Demonstration of Lapds in a slightly different context than previously the first sandy deployment aims to study about 2 to 4 weeks of beam data.
We will be removing it again, and then pushing towards the the final full deployment of our 5 lapds.
Our next step is well. We have everything in hand. And this this was a long time coming.
We had a lot of minor problems with with our electronics.
Boards do partially to aging and time, and also a few other issues.
But we're now at the point where we have the full suite of electronics.
We need to finish our 5 deployments. We plan to take the full beam year next year with all 5 lap Pds.
More Lapb's can be added to any than the 5 in. Situ.
We do plan to increase the coverage. We'd like to work up to.
We've said in the past 20, and and I think that that would be an excellent goal.
I think some of our future Lap Pd interests are in trying out le gend to lap.
Pds so that we can study the reconstruction comparatively in the same detector work, is underway to finalize also designs for upgraded electronics.
A lot of the challenges and lessons learned with the first deployment are easily addressable in in new revisions of the boards and work on that is, underway.
This is the site I presented last time, so I'll just go through very quickly.
Noise and heat inside the module power management are definitely technical challenges that one needs to consider that again, those we have largely worked out.
The still at this stage with Lapds. There's some hand tuning for individual Lapds.
It's possible that we can mitigate the design with with a design that independently controls the high voltage settings for different, Lapds, with a design that independently controls the high voltage settings for different lapd layers.
Right now we're using a single voltage settings for different lap Pd layers.
Right now, we're using a. As I mentioned, we have lots of small changes that we wanna make to our next revisions.
The electronics, but one of the design challenges is that there's a frame on the outside of Lappds is delivered that has to be taken apart when certain aspects of the electronics are modified.
We've mentioned this before, but community wide efforts to come converge on a generic design that makes certain kinds of these modifications easier would would be, I think, a desirable thing for the community, and having some sort of standardized interfaces that we can all agree on would be very useful and
you know, one of the reconstruction challenges which I'm excited to say we've got a lot of data to work with on is multi-photon disambiguation.
So if you have pile of a photons on the strip lines of an Lappd that could be challenging, especially when you add real-world effects like noise and and end other sorts of issues along those lines.
But but there's a lot of promise that that's the summary.
Basically, we've constructed and assembled our detector.
We've put 3 lap Pds. In the water.
We've tested Wbls. We'll hope to get all 5 in the next several months, and then next year it'll be a fairly.
My dream is a very beige year of data, taking matched by a very exciting year of physics and reconstruction with Lapds.
There are lots of opportunities, and new collaborators are welcome.
Alright, thanks, thanks, Matt. Any questions from the audience.
Oh, Sylvia, go ahead!
Yes, thank you for this presentation. You have shortly mentioned your electronic chain, and I have not understood.
If you use or do not use amplification before analyzing your signals.
No, we don't use any preamplification of the signals.
So we they go directly into our readout electronics, and we've found that the signals are are adequately sized to be able to do that.
Yeah.
Okay. Thank you.
Yup!
Alright. Okay, let's move on to the next. The talk.
Alright! I can see your slides. Go ahead.
We kinda hear you. By the way.
I can hear you now.
Sorry I muted. I was still muted.
Okay.
I forgot the mute. Okay, so just a short update that was not much happening since the last meeting.
We almost a year. We don't have lapd in the lab, but hopefully soon we will have new samples, so we will be able to continue so just first few slides will be more or less introduction that I showed last time.
So let me go quickly through them.
Okay, let me try like this. Okay, so we have lap.
Pd. 109 and so you are familiar, basically with 20.
Micro of course, with the same as all the others. What we use is a 2D.
Stage with laser focused Tom to less than 100 microns, and with full data marks of about 20 peak a second from producer.
So then we detect multiply with mean module and discriminate with new multimodal, and then the tech tdc, in the in come up module and Adc in the Vm.
Mode. So this is our setup, and there is a little bit more into backup.
Okay, so this is the standard. On the left is the standard backplane from the income, and on the right is basically the backplane that we produce with different patterns so what I will show is basically today, most of the measurements are from this area it's 5 strips and
3 one inch beds, and also an update on timing from the Faustic or the Channel.
We just connected here on the half inch back. Okay?
So what we do is measure. The Adc edc, typically with a standard connectics, make a correlation and correct it and correct it.
Tdc. Is what one would expect. So it's about 40 picoseconds.
The main peak. Then there is a shoulder, and then there is a basically flat extension of the backs get the elastic cut of both electrons.
So this is a typical spectrum and chart sharing was actually what I showed last time this was the main interest for us in the beginning.
So it shows that this is one each, and you can see that the charge is spread well over the dominance of the pad.
And this is just a blow up of this transition from middle of one path to the other path.
So this shows that the signal goes well beyond the path, and when you measure the timing in principle, what we what I will show later is how this changes the timing changes with the position.
So, as I said, the previous one was measured with the Standard Income Board.
This is a part of the beck, please, that we produced.
This is the job sharing between the 5 and the timing for 5 is not bad.
Actually, it sleeps 2 inch long strips 5 width, and the timing case, and awfully, the solution is roughly the same as with the bets.
So the size didn't really change the timing. Now, few slides, basically of a position.
Dependence of the timing. So this is the now, the scan along this one inch pads below channel 1, 2, 3, and you can see on the bottom.
This is on the scale. What is actually plotted is the position on the X-axis and on the y-axis.
Each slice is basically the timing distribution. So this is the main peak, the shoulder, and then the back scattering on the you can see the back scattering bottle liner scale is actually not so.
And this white roughly the boundaries between the pads.
So you can see that within the bed area, basically, the timing with end position stays basically the same.
But the signals that are detected from the illumination of the neighboring path actually are detect detective Delayed.
It might do something without the way we connect it, or some other things.
It's not really at the moment started. So. But within the bed it seems to be basically stable.
This is the left bats the needle pad, and this is the right path, and this is also the logarithmic scales.
So you can see the extent of the elastic backscaping timing on the back.
Now what we usually did already many years ago, when we started smaller ones, was to basically select only the timing from the channel which produces the maximum.
Signal, because sharing was also also happens on the last stage, and was also, in the previous samples that we had.
So if we limit only if load the timing only for the signals that produce the maximum response on the corresponding channel, then basically, you can see that the distribution is much more flat.
But that is still a little bit of variation at the edges.
So this is what the scale over the middle of the bed.
Then we'll probably be a little bit more on the corner, but it seems to be pretty flat within the surface of a bet.
What what actually happens at the edge is, we still need to start.
So this is one thing that I updated.
The other thing is, we scale over the somewhere here in this area.
There is this spacer we have a we have an lap. Pd.
Which had 2 parallel spaceaces not across. So this is the scan, basically over the spacer.
And you can see, this is the basically the typical disruption of the signal on dispatch at Number 2, and you can see that it's follows nicely, except for the area of about 4 when it actually it's basically that this left.
Is not very good plot, but it's basically just the Adc as a function of positions. But you can see that again.
The in a bit wide range of about 10 but actually the with lower gain.
Of course, still works, it does work in a range of roughly 4 and this is the variation of timing below.
On this area. Here is again blocked it with marks.
If the maximum was detected on this channel, and since this channel iss don't have the same geometry, basically, this does not really well separate the bigger and narrow strip on the top so the white is basically the bombed area, so you can see that in this on the right side this
is from this thing. The timing from the Steve.
When we go on the middle of the street along the street, basically.
So you can see it's pretty stable within this area.
As I said, this marks selection doesn't really work well in this case.
So this is the old. These are all signals. This is the chat.
This is this large pad, number 2, with a space that in between you can see some variation of timing around the space so, and then this is the street, basically.
City actually goes beyond this area. This is the neat of the street here, so you can see that the timing basically is again flat in this region.
Okay. Now, the last is an up to just a quick update on the solution with plastic plastic is a cheap that will eventually end up as a past the reach of something like that.
The name of the finals of Asic, which will have more channels.
This one has actually 4 differential channels, or 8 single end.
Its. So we made the rotable board to take for 8 single-handed channels connected to the backplane.
Now the electronics from the readout, the Vme model that was used for Tdc. Is slightly different.
So it's has about 25 speakers, Jeter and let me just go to the next slide.
So this was shown over the last time. This is uncorrected.
So the output of this Asic at the moment is just a discriminate and output.
So it produce a leading edge signal in Lvds logic, and this was connected directly to the time Pdc.
Module, and without any correction of the pulse side.
Basically, the solution was about a 150 picoseconds.
If we are in the middle of the path. This was basically scan of the larger area area, and if we are on this path, then the solution without connection is about 150.
Now the signal was actually too narrow to we saw we were not able to get.
This was the last minute. Basically the test with this electronics, we were not able to get the time of a threshold from the information from the Asic itself.
So what we did was to pull back channel and measure the is the charge shared signal on this channel, and then blocked the correlation.
The timing from the and the ABC. Which in principle could be obtained from the time of that threshold.
Now, as I understand it may be possible also, for this short singers, with adjusted plastic parameters we didn't have time to learn this, but so maybe it's it is possible.
Still with this A/C. But anyway, each shows that. Of course, if you correct for pause variation, then the timing gets better, and this is again non-core non connected on top and correct it on the bottom is roughly 70 picoseconds.
So that is the digital part at least gives the output on the order of 70.
Picosecond, including all the contribution from electronics place.
That is a certain connect each other at this level. Okay, so that's it.
Thank you.
Thank you. Thank you for the talk. Any questions from the audience.
Yeah. Correct. Go ahead.
Yeah, you showed that the timing resolution deteriorates around the support regions that supports that but I'm just wondering, does it?
Did did you measure the timing at the edge of the detector near the boundary of the detector wall?
The edges, if you like. On the other picture. Is it?
Do you think it changes as you get close to the edge of the detector itself?
No, not this time. It's actually actually my I mean, I didn't measure with this one.
I would expect something similar, but I don't really know what is the old. I mean.
I would say that the resolution doesn't really change just the delay changes.
So if you combine all without any correction of course it will affect their solution, and I don't know whether you have the information to correct.
Yeah.
For this. So this needs to be started also. Here also.
Here one could say that the No at the edges.
I would expect that something seeming that happened at least with the smaller devices that we tested many years ago.
They had a similar St. That effect at the edge, then between the channels, but similar the shift in the delay, but not really the shift in the the spread. Yeah.
Yeah. That's what I'm thinking that even without the spacers, as you get near the edges of the detector maybe this is, it's difficult to correct, for at least and maybe there's some timing.
The effect near the edges, so.
We? Yeah, we didn't. With this first measurements.
We didn't really test the all the just.
Yeah, right, right?
Some parts of the lapd. But when we receive it we even do it.
Yeah. Okay. Thanks.
Okay. Great. Sylvia.
Oh, it seems a question for clarification all this time, and resides in that. You have shown some.
They have been obtain in single fault. Electron configuration.
Have I got it correct?
Yes, typically, it's in the sample. It's more than 90% single focus.
Yeah, it's a very weak signal. So there are always some small portion of double on worthy photon.
But more than 90%.
Yeah.
Yeah, yeah, the nice detail is just to make sure this. Okay?
Great. All right. Okay, great. So, thank you, everyone. And then I think, we now can conclude that the first section and we have a coffee break for 10 min that's 1124.
So we have the less start, and the 1130 or 1230, or 1235.
But we continue, Alexander still be there.
So that may be needed, I would say.
Yeah, okay.
Alright, so let's have a 10 min. Break and back at 1235. There!
Okay. You see the screen?
Yes, yes, it's not in a full-screen mode.
Not yet. Huh?
Okay. Now should be full screen.
Yes, now it's fine, and I think we start so it's already.
Oh, okay, so this is an update of the status for we deliver Ppd.
For the hub in our client. I will give a brief reminder how the aims of the project, but if you look for the information and also have a lookup to your results, you can refer to the to her your Lapd workshops, and links here for your communities and what we are going
to discuss today is the results of the latest being tested.
Daisy, with the electrons from one to 5 point Tengb.
With data taken last December, and we will see the results about the timing resolution that we got the position resolution and also reduction efficiency.
So a quick reminder is here. The 2 will operate in a hashtag environment that delegates see with of protocol edition. So about 1.5 times 10 to the 34 there would be a high background in the most central region.
And what we believe is measuring the time of the heat.
Would be crucial, to the pile up, and in particular simulation indicate that a timing resolution was about the order of 20 people.
Seconds is necessary. So the idea is sketched in this pictures.
On the top you see, the colorimeter is divided in 2 h, and then a tiny layer is inserted in a in in a small gap.
The other idea, which is pretty simple, is, that is, to operate in a photocopulous mode.
So you have a target particles from the community shower which are utilized directly.
Electrons within the course of the Mcps. Such that you can get rid of of the photocopath.
And then you don't have the problems of the lifetime of the photocopy, which is the earliest one to die with this, this type of detectives.
So consider that we are talking here of integrated charges during the lic time, of the experiment of the order of 300 Coulomb space centimeter, which is still in order of magnitude, larger than the best themselves, that are that layman for example, as demonstrated with existing okay so
this is a sketch of this premises at the top, and Daisy.
We had an electron beam and then in a centimeter twitter which was used just for triggered the interaction to records for time.
And then 3 tracking chambers. What you see here on the right is the front half of the eagle module, and then there is the Pd.
Which is getting this electromagnetic showers and measure the time.
So we use it. A custom-made.
The Aap Pd byin comma, which was with the cycle 3 Mcps.
In z star configuration, as I say, it's good for cartoon less operation.
And then the current model was relatively small, about 4.5 cm inside it was covering just a little region of the much larger Itbd activity.
So this was a generation to a Pppd. So we were working in practice with 4 only 4 pixels, which were the ones which were colored by becoming a model.
Okay, so let's move on. And this is just a sketch which indicates where the company needs to model was placed.
And so which were the 4 pixels affected by this measurement, and then we also perform this kind of the beam position in order to illuminate various regions of these 2 by 2 pixel metrics, then one problem was how to
combine the measurements of the 4 different pixels.
So, because in general you may have a in electromagnetic shower which is spread over more pixels.
Certainly when you eat integrated, but also I do it on one of the pixels.
You may have particles spreading goals on the surrounding pixels.
And then one problem was how to combine this, what we did, what we use it, the machine learning approach in the end.
So with a important.
So these are the input variables from the 4 pixels.
So the amplitudes of the signals, the time it's a 10%, 50%, a 9% sign signal 8.
And the position indicated by the tracking challenges so what we did do we train with the the regressor on a subset of that measure.
The performance on the rest of the. So before go ahead, we made the first the voltage scan in order to understand Optima voltage sets of the.
Fcp. So, as I said, we have 3 Mcps here, but then we also have the possibility of that.
The possibility to disactivate one of the the top one, so we could in this case, since we are not using a photocapher.
So, if we, if we in a bit the upper Embassy, we can work with the meeting to once, and in fact, what we found is that with 3 active Mcps we get having resolutions which are at best around the 25 people seconds.
This was for run of 5 Gd. Electrons, where we 2 active Mps.
We can go down about 20 picoseconds for 5 Gdp.
So, for this reasoning the following, we will show the results with the 2 mcips instead of 3 so far we reduce it ourselves to a region which was far from the edges of the E of the pixels simply because we couldn't use the information of the surrounding
Pixels because they were not covered by the calorimeter module.
So this is what you see here in the center is diffusion of region that we use and the values see, are spots that you see are the beam spots.
Each spot corresponding to a different rank, where we were scanning the position of the so due to the big auditions, as you may see, it was impossible to have events distributed very uniformly.
However, we were able to get the decent coverage of the meetings.
So what you see in this slide are the timing resolutions.
So these are the time measured as an output of the Random Forest regress, or combining the information of the 4 pixels and the reference the type of the reference Pm.
Cpk is so from one Gd. To Gbp.
To G. 4, 5, and 5.8, which was maximum energy, that we measure it.
And Daisy. So you see that the distributions are Gaussian mic, I mean, and they even improve the integrity going from one Gv.
To to the largest energy of 5 point Eightgb. And here are on the left you see the dependence of the title solution as a function of energy, where the type of solution of the reference and Cp's already been subtracted.
So what you see here is the plane time, resolution that we get from the Ppd, so you see, we are about 50 people.
Second one Gb. And we reach about when 18 people seconds.
Okay. Then, another thing that we said we wanted to. What was issue, resolution.
We could achieve with the with with this a generation.
For Mppd. So let me remind you this Lpd. At 2.5 cm speech for the another pixels.
So the pixels are really large.
Then we try to understand how much by compiling the information again, of the 4 pixels we can get in terms of position, resolutions, and you can have a look here.
So you see, this on the left is the the quote real position of the impeaching electrons measured from the tracking chambers.
So in this is a an Xy plane, and that you're right is what is seen by dealt with.
So it's, you see, the same pattern, but it's much more blood, because you know the pixels are large, and however you ever you may have any idea of what is going on, and then we can look at the one dimensional distributions of the resolutions
of these are the resolutions in the position measured by the Vd. Minus the position measured by the attractive chambers, and then you see that the solutions have good good sanity in general for each of the technologies, and if you look at the dependence of the position
resolution, function of energy. You see that we go from about 4 of one Gb.
We are about 3 met meters. This is the so, despite we are working with the pixels of 2.5 cm in inside, we were able to achieve at best 3 in in a position resolution is just the distribution for x but
for wider. Okay, the last part is on detection, efficiency.
So we want to measure to understand those cases where the Pdp gives no signal, and this can be both to or either to automate showers, situation.
So you don't have enough particles. Reaching the Dlpd. In the shower.
This is particularly true, what the energy is more so around one Gd.
Is then then the multiplicity of the particles in the shower increases almost linearly with energy.
Or can be due also to an interesting inefficiency. So not all the electrodes which traverse the emcps are unions in the right positions, such that you can get the measurable signal leading up.
So basically what we do, we would take cut of the sum of the 4, the updates of the 4 channels.
And then this way we get 3 dot events where we have no, no, no, no! So we count non-empty events from this black line onwards on the on was on the right.
Okay. Okay, this is the same block in line, right? And then this is what we got here.
So you see here the efficiency defined this slide before as a function of energy.
So for one Gb. Electrons, we had quite a drop in efficiency at about 75% for 2 Lcps.
But you see that with 3 Mcps we have a larger efficiency in general, which is this is because I mean, we have more material.
Where the initial electron can be inside, inside the Mcp.
So it's higher. The probability that the signal is.
And also I mean so, whereas I see that 2 Sps are better concerned, time, resolution, because you have lower transit time.
The detector. So also, with the transit time spread but 3 are more efficient and lower energy, and also the idea of starting an Ltp with 3 andcps is that it may be also beneficial for highway to population but this has still to be understood okay, so in
conclusion we have operated, the less mode with the stack custom made by income and data will collect the daisy last December.
We'd like from one to 4 5.8 Gv.
The laptop was placed at the bottom shore maximum within a kilometer module.
We use the mathematician approach to combine the information of multiple.
We got slightly better time resolution with 2 up to the Cpc.
Instead of 3 in the range of 18 people. Seconds for 5 point Gg.
Electrodes and 50 people seconds for one Gd. Electrons although the picture size was larger 2.5 cm, a good position resolution within 3, and the 4 was achieved by compartment definition of the 4 pixels and we observed a drop in detection efficiency
at one to Gb. With 2 Mtps, which was better with 3 emcps.
We think that improvements, both in time and position, resolution can be expected and slightly reuse a pixel size.
So let's say, it picks its sizes of around one centimeters in pitch, and then we are coming.
The best at service. Ps. In in next June, with electrodes from when to Gene to 100 plus and more. Gb.
Where we diet energies in general, we expect the even better performances than in base. So we wish to take invaluable support. Thanks, that's it.
Thank you, Vincent, and we have questions. France, please your first.
Hmm, yeah. Hi, Vincent, I'm trying to understand.
And putting put put in perspective how this works for you, I mean, where are the electrons generated?
Are they at what do you call when the map versus a boundary?
When? Yeah. Yes. What?
And do you know, and do you know how many MIPS per centimeter of Mcp.
How many Inish primary electrons you start out?
Okay, so this is an estimate is not the precise measurement, but yes.
So the electrons are generated on the surface of the Po.
So when the a track in this case, in electoral or a positron, noble, the shower crosses this is the internal space of the port.
So these electronics are detached from the the both part of the efficiency for a single particle is in the is around 70%.
So it means that when you have a single particle charged particle toverse in the detector, it's about 60 70% of them release a measureable signal.
Hi! In a shower you may have even tens of particles.
And so basically, you know events, you, you have a signal. But if you use it only for a single chartered particle value inefficiency with this photocopy.
I think you are muted now. France!
Yeah, to turn it around your time resolution of what is it?
1020 pico second, or even better. Yeah, how much of this is due to square root of N of having many.
So what we measured that in the lab with with the laser is that with the single photo, with this model we we can get something around 50 picoseconds.
So if you want, I mean a raw estimate, because, of course, yeah, what we are doing here is not the same thing as using it.
For account of the laser. So, but roughly, for a single electron, let's say we would expect to order of 50 50 vehicles.
Oh!
Maybe in our case, even more, because the difference with the photocopied operation is that all electrodes start from a given surface, whereas in this case you have a spread which also depends on where the initial electron is united meeting Dmcps however, order of 56
Pico seconds for a single port. Electron. With this model.
And then, yeah, for the rest, it comes from the square root.
But you also have to account for the fact that not all of the particles in a shower are perfectly synchronized.
Yeah.
So you have a time spread also devolution of the shower that these, with the performance of the detective.
But now I'm confused. I thought you only had the Mcp's and not the photocode. Or is this incorrect?
No, no, yeah. I mean. So in this, in this, in the beam test, we use just the Dmcp.
And with delay. So you put the photocaster in front of it.
There is a photocopy in in in the tuned.
But we need it during the test beam operation. So we put a yes, such that in any case we don't have any.
Okay, yeah. Clear. Thanks.
But in the that we we can.
France was that? Did you get the answer? Because I think we also need to move.
Well, thank you.
Yeah, I'm done. Thanks. Oh, yeah, I muted too early.
Sit down, please.
Yes, so thank you for this very interesting result. Been changed. So.
But this is also 3 gap. Some question, for example, if I have understood correctly your electron beam was always illuminating a very small portion of the surface.
Yes, but when my show results, we are putting together all of the runs.
So we esc scanning a lot.
But this means that in this way probably it was difficult to get collective effect in the sense that tomorrow, in a large cloudy method, what do you form a shower of a certain size, you will have at the same time particles crossing a different points of the same device.
Timing device, I mean, and therefore this taste is not giving you an answer about possible.
How can they say effect? So I wanted it due to the correlation of more.
Amplify this multiplied particles crossing the same device.
So you mean, you mean, you mean that we may have pile up of particles going to the same region this?
Byile up, or whatever also the fact that the devices are assisting.
Can can play at all.
But well, probably what you mean is that you may have some put in quote Cross told from the from the fact that you know if if you raise the charge on the car from your pixel at this will spread out and then new level, so
some signal in a in a factor. Pixel, this is what you mean.
Hey? Guys? Yes. But if you have several particles, you can have also only shorter timescale, a reduction of the effective voltage, because the distribution of the voltage is via.
So I don't know. I'm just asking.
Okay, no, I.
And the second thing is in the same direction is now that you have so clearly explained that you generate your second body.
Electrons on the walls of the microchannel plate, and as you expect it to work at higher rate in a clouded environment, as it is at Lhc.
Do you imagine to study also aging effect?
So we. I showed some studies in the previous.
So if you go on the links that I put on in the outline, and the previous presentation I gave with the last lapd worship, there was the result of a study made by irradiating the Apbd.
With 10 to the 16 protons. So in a square centimeter.
And then there was also another study of the gain of the Mcps.
As a function of the integrated charge. Where we reach it about 300.
Okay. Good. Thank you.
Kilo per square centimeter. So it doesn't appear that there is a problem of aging, at least up to 300 a quarter of a square centimeter, so that well, not there is an agent, of course, but is not I mean it's an agent, that you can
compensate by changing the voltage bias.
Now. What matters most, however, is the operation, high rate conditions.
So we what we have seen is that if we exceed all of N megas per centimeters of charged particles, the game starts to be very low, so probably the I'm not probably for sure.
I mean the most important aspects. To understand that now is the operation in high rate conditions.
Okay. Thank you.
Jeremy.
Okay, I have a question, what is the total charge?
Per shower you see on the Mcp.
Well, that, of course, depends on on on the voltage settings.
No, I mean for your typical condition.
Hey! Now, I don't have the numbers out of my mind, but you know, so I can.
So!
I can make a backup. The online calculation, since in the end we are working with relatively low gains of the order of a 5, 10 to to the 5.
So, if we have say in a shower, we have, say, 10 p particles which corresponds more or less to 3 gb, so 10 particles in then assuming that on average you are united wireless with the particles is 5 to 10 to the 6 for a per hour for the Gd and that
Yeah.
increases linear. So for 30 Gvs. 10 times more for 300 Gvs is one of the times.
So for the largest value. Do you see any of the pulsing?
Did you look at at that?
But no, we don't see any of the pulse in in the samples.
Yes, yes, but so.
But how can you make them so? You mean you mean an eye on which it's the. It's the internal wall and starts another. Now we did not observe anything like that.
So that's that could indicate that the after pulsing is caused by photocato. You don't have photographs right?
Okay.
Yeah.
No, no, we don't have photocopy. Well, yes, it's it's I mean, it's something that can be said for sure after passes mainly come from photocopy.
Yes, so so the only sort of limitation I since you don't have a photocopy, the only limitation I can see is that the microchannel plate is a kind of full conductor, actually.
And so you can charge it up with.
What do? What do you mean? A conductor?
Well, it's not metal, it's not metal.
So it, you know.
I mean it's well in this case for the incommensity piece. What you have is that you have a layer, a conductive layer, I mean resistively, actually, which is deposited on the surface of the post.
When you have a strict current which which continues, inflows in which is really wrong.
So inside the upcps there is a high impact, actually, which is always there, even without any any electromagnetic shower.
But obviously you you can with a lot of charge.
You, you can basically start the being limited by the resistivity whatever that is.
We don't charge. What you are limited for is the replenishment time of the so if you are very high rate, of the deposit of of a limited charge, then your for start to be quote a good discharge it, and so you have to
wait that the stripping current which is flowing in the force recharges the posts, that they are ready to create a new avalanche.
That is the usual problem of Mcip. Pmt's.
For?
So did you measure time, constant? How how many?
You know how long it takes before the Mcp. Is back in sort of nominal situations.
So the in in the s beams, not because the rate of the particles from the beam is relatively low, at most, that certain is up to a few 10 kilos, whereas in a in a days it's just order of one kilos, so the rate of particles
initial particles is small in the laboratory. Yes, we made measurements with direct bounces laser pulses, but I'm not sure if it here.
Yeah.
But I mean, if you want a doctor of magnitude of the time, the port needs to be recharged, it is the order of a Mini second, which is the tipical, the typical time.
So it's a long time actually.
It's a long time. Yeah, but fortunately you don't ever.
It's a good pool, so, since you have many pores, I mean the strategies that is that of reducing the number.
The sites of the Post such that you have a larger number of boards per unit area.
Now, income is come, is now started to produce 10 migrants hopefully in the future they may go even below the micro and the other strategy.
Yeah.
To cope with their rates is to a large distributing current in order to recharge more quickly. These are the 2 basic strategies.
Okay. Okay, okay. I think that I ask, no, okay, thank you.
Okay, thank you. Vincent. So I think we need to move on.
And your second talk. Please.
Okay. So Alexandra, asked me to give this talk, and a bit a shame that there is.
Stephanie connected because he is the one who invented this, and so knows much better than me anything I will be talking about, so I hope you will forgive me for any.
Okay, so so we were talking in particular, the 1742, which which is is a Dmv.
Board, we talked to channels plus 4 channels for the 2 trigger inputs which are based on the Ts 4.
So we have 4 ds, 4 Cheaps, 8, signals, plus one trig so each cheapest 9, 9, 9 9 inputs.
The maximum cycle rate is 5 giga simple per second, which means around about 200 people seconds per set on average.
In this case we do need 500 we have a full acquisition.
We don't offer 200. Then something in our seconds the board comes, break and graded from the factory.
We didn't know it integration, but did the for calibration, we found is largely above email.
And so one needs to perform at the of calibration, for you want to achieve.
The performance is for the Us. So that's 2 types of calibration.
One is concerning most of the job sets for reach, sell.
When I say, sell an email, a capacitor of the of of the capacitor rate and and and then also you have to calculate the time rate of each cell and so the calibration has to.
Go beyond set by cell, which means, I mean a relatively large number of cost costs that one needs to.
So just I mean very briefly, on the concept of the Ds. 4.
This is based on our S. E. S. Which capacitor are raised operating in a sample in all mode.
So there is a fast sequence of like pulses which allows the recording of the waveforms in the capacitors at very frequency, which then can later be read out and digitizing by ABC.
At a much lower speed, and then each cell comes with a random offset, which is cost over time, although there is a in mind dependent on comparator. I mean, we didn't observe with normal temperature ranges very very large differences.
But it is well known that if you have a cooperate in a wide range of competitors, you may have to take that into account for the voting.
So this is the plot taken from this paper, which I think was one of the old.
So let's start from the offset calibration put kind of bring the one to just injected into each channel of the board a set of custom voltages so, for example, 3 points are ready enough to make the
fee. So, for example, from minus 0 point 4 to 0 point 4, passing by at 0, remember that the full dynamic range of the Ds.
4 is about 1.3 to be more actually, and the for each set is that performance on the voltage as a function of the accounts, and then the cost of from the feeds provide the absolute voltage calibration which not obliterate. So you see here.
For example, yeah, we took much more than 2 points in 3 points in this example, when you see the voltage as a function of The DC counties, and there is a very good linearity.
And then on in the middle plot you can see a typical fix of voltage before the calibration. So I'm kind of graded.
And then on the right hand side, you see the same one, but after applying the calibration, and then on the bottom plot is the distribution of a single channel of the receiver.
Noise after calibration, and you see that once you properly calculate the cheap, the electronic noise, which is typical of the years for is audio of 0 point 5 menu.
Okay. Okay. Then, going to the same time with calibration.
This is more complicated, there's a one needs to measure the effect of the sales.
And so the basic idea is the same paper that they see before I found the also the same idea described with the paper by Dominic I collaborate, so do I couldn't find the reference when I was preparing the talk.
But I'm sure you can find it if you look around.
We just made this more improvement to the technique, disturbing the paper that we weren't using.
The procedure that was indicated as the technique and then describing that paper.
So we made a little change such that this is not no longer necessary.
Then the technique for time calibration is just to ensure the channel of the board a fixed frequency.
Some waveform 4 or 5 data sample per second. The optimal frequencies are in the range of 50.
100 megets, whereas for lower, for for other separate grace over simply creates, you may choose these accordingly, and the idea is to look for 0 crossings of design reform.
Ideally, it can be done even faster with the triangle of form, as the linearity of the term where we form a one to use more points and not only 0 crossings, so less lower statistics, if you want to make the good calibration, but in order to have one of the megas.
we travel away from you need to high end the box generator that we actually have.
So we tried both triangles inside. We in the end I mean, we try and go with less events.
But indeed, the results are okay. So if you look, then after the calibration, you make the distribution of the time with the of a single sell, I mean you.
Oh, sorry, obviously good Channel. You see that each sell as a def time wheat.
And in this is what Stefan was commenting on the some talks ago.
So the difference between sales can be on average order.
100 people's seconds. But you know, if you consider, the tastes can be even 200, because I could, then you may have all sorts in some rate cases, even in some chips.
But this is very great, I would say order of 1% of all the channels may have such an issue, but in any case, if it happens, you have to take into account also that what you see on the right is that so as I say, old and these 2 picks.
Correspond to all 10, even cells. I don't remember which one is, which is even.
But it's not fair enough, and then you also may see if you plot the cell number.
The time, we, as a function of the cell number.
You also see that the first 500 to 12 chapters and the assisted offset, and then the rest.
The reminder of the channel. 7 other offices.
So there are 2 distinct regimes which are separated by 509, 12 all of this is well known, by the way, bye, bye, bye, bye, bye, bye, bye, bye, bye, bye, bye, bye, bye, bye, bye, bye, bye, bye.
bye, so nothing new. Oh, that in order to cross, check the time accuracy of the calibration, what can make a simple signal to test?
So what you see here on the right, you take one signal generated by with generator or whatever generator, and then you split it into 2 identical parts, and you send one part, one signal, one of the speak signal to to channel, and then you take the time, and you
take the time, difference. So you can make this test easily.
When you are working within the same Prs for chip this test easily when you are working within the same Prs for Chip. But, for example, the 70 42.
As for Chips, so if you want to synchronize them, you have.
You have to use some one channel, basically that you know.
I mean that you feed with with the with the speed signal share the commons that you can use that one as a reference will hide the time of the different years for Chips, for example, in the case of the seventeenth Plato, you can use the trigger
channels themselves to do this job. Then just a was light of the experience in the knowledge so that from my end effect they came to borrow the last 3 April, the third. So the basic tools that we use at the okay time, 1742 in this case they at the
vme Controller read out by, you know by USB.
Or alternatively, you can use direct in the of the 70 42.
Then we add the standard pass generator, which was from Key Side.
And then, okay, the other basic tool is a root-site. And then, okay, the other basic tool is a root based software code which is needed to produce the growth here is not really essential when you could be bringing into quite easily from the code so in the afternoon over the third we calculated together the
channels. The first 8 channels for the first year for cheap, and tested a 10 year solution between the channels in the full day operate for but alone. So without my yet they calculated the remaining 24 channels, and then on the morning over it will be fine then calibrated to keep the channels and test the table between the different groups
so we challenge us using the figures as as a reference forcing conversation between the teams.
Hey? That these are a few plots, other prosperity by chartered them.
So this is the type of solution between chunks 0 minds X. Wex. It goes from one to 7.
So one challenge speaks, and and then we move the other channel and measure the time of solution between the 2.
So you see that this is all in the back of 2 pixels seconds.
You may have situations even up to 2.5 to 6 picoseconds, because of the chance.
So we have not stick to the integral. And then another interesting feature is this, one.
So if you look at the time offset within the channels, you see that there is a pattern which probably reflects the length of the tracks inside on the PCB.
Conducting the signals from from the connectors to the Dl.
For chip, which, of course, I mean, it's quite understandable.
And then here, okay, this is the plot produced by them on the Trigger channel.
Set time with distribution, which is, course, is a channel like the other. So it's exactly the same pattern.
And then here is the approximation between 2 channels of 2 different groups.
Use using by reference the 3, the figure channel, and they measure it about 3.5.
People say, 9. Resolution in this case. Okay. So to conclude, 2 full days are enough to explain the logic and kind of break those channels of a 1742 kind board with about 2 3 Pico second, precision and in case one needs to calculate multiple boards.
That necessary some automation would be needed but for the one of the calibration procedure that we were open and the code I'm not hopeful for that, because we had just 1 2 boards.
Concentrated so was not worth making an effort to automate it, for our case.
Okay, I think, I finished.
Thank you. Vincenta, and of course I asked you to give this presentation on purpose, because there are several groups which are using these modules.
And this knowledge transfer. So if it, if it was possible to share the coins, let's say.
Yeah, the code is the code that? Well, of course, it is possible.
I share the code with with that big Chandra which are free to share the code.
Okay. Very good.
We do whatever they want. If if you want to ask me I mean, of course, there is no problem oh, there's no problem for me.
There is no problem, then.
And then, if there is an instruction or something like, because not everybody can come to can visit you for.
Yeah, well, this is unfortunately, I never managed to make any documentation, but I mean, the logic is well described in the paper by chef and the collaborators.
So that is exactly that there is just a small modification.
We avoid the procedure that they were using, but besides that, the logic is basically the same, then the code itself, it's basically the same. Then the code itself, you know, it's a simple mind that I mean, it's not anything fancy I mean, it's something that was written for the park also being used
by by a few people, so I think I can share it.
I can. There are some comments in the code.
I can provide some help in using it. That book started to use it and learned to use it in a in a while.
I mean in a couple of hours. So it's nothing.
Probably we can ask them to write a manual.
Well, I volunteer. Don't ask me, please, because, unfortunately, I have really a lot of things to do, so if they can. It could be more than a.
Okay, save that. Please go ahead.
Yes, so thank you for this instructions.
Talk. If I got correctly from your words. That is the following aspect, that when you would like to use China is from more than one cheaper, then you need in a certain way to satisfy one channel per cheaper sending the same signal as a reference, have I got it correctly.
Not exactly in the sense that we did. The 1742.
You have at least one channel. Which of the Ds for which is already devoted to the 3, and so you can use the trigger channel directly to make this synchronization, since in any case you have a trigger, so that is that is already enough.
One thing that I didn't touch. Here is the existing of the spikes in the Vs.
4, which is a feature, I mean an annoying feature, which which is there that can be easily intercepted.
For example, if you waste the channel. So if you're the user channel, and then you look for spikes in the channel, you may recognize those and then correct.
Then the other in the other channels, because they are synchronizing in time, however, in general, we have seen also we have been challenging a few weeks ago.
Even if you forget about the spikes. The effect on the global performance, this is is almost irrelevant because the spike becomes relevant when they accept 3 append on top of the rising front.
We check that with the very low probability, anyway. So those can be can be forgotten that I would say.
Thank you.
Yeah, I've 3 things to comment here as I can imagine.
Okay. Great.
First of all, the spikes are solved, since it's like 5 years.
Okay, that's great.
So I understand where they come from, and they can be easily fixed by a firmware modification which brings me to the it.
Actually, I can maybe tell you offline what it is.
Huh!
But you put you need to modify the firmware, and in your case you would have to talk to Kyan, which basically me to my second point, I mean, it's really nice to see that people understand.
Now, the time in calibration, and they want to pass it on to the next to the next, which is kind of cumbersome, right.
So, since there are some Italian people in the collaboration.
Have you ever thought talking to kind about that? I mean that, as I understand, they don't have the resources to put, if also themselves, they just want to sell ports right that they don't have time just to fine tune things and because they won't get more income, by that but if you
Yeah.
have good context with Kai might be. Somebody could not go to Bologna, but going to VR you, it kind work together with them, and then fix it once and for all, so that everybody then buying the ball from kind would benefit from that right?
And I would, and I.
That's a good point. Probably Syria is the most indicated one, because it's the.
Yeah, yeah, and actually, I'm happy to help.
I'm happy to come down to that. We are rich.
I like it myself, and not that I can teach everybody. You know how to do it, probably in order to avoid double and truly work right.
So it's kind of cumbersome.
Yeah. Well, in principle, they could also quit the boards with with with the line back, and then also with the with the oscillator, and perform the calibration automatically in principle.
Exactly. Exactly. Yeah, yeah. Yeah. And the third part is you mentioned already?
This between the chips, sacrifices channel, or use the trigger channel.
So. The point is that the each chip is controlled by a pl, and this P.
Ll between the chips between 20 and 30 picoseconds.
Yeah.
That means if you start comparing between Chips and you don't do anything, you get an accuracy of 20 to sort of picoseconds, which, as I understand correctly in your case, is too much so.
Indeed, there's the nice channel of the Ds.
And that's exactly for that, you know. So to assemble something on the ninth channel.
However, it does not make sense to assemble the trigger, because the resolution decreases.
The wide of the signals are upon. So if if we measure the time between 2 signals which are apart, 100 numbers against them, the solution is much worse than if the signals are part.
But you know, a second something like that, because this is slowing between the channels increased over time right?
Yes.
And then get fixed on the next round. So, having a Singapore, it's not very good.
So what we do in our experiments, we put a 100 Megahertz clock.
What on this ninth channel, and then you have every 10 on the second.
Yes, so!
So you have a edge, and then you choose one edge, and then the maximum delay.
You have between the edge and any signal is like plus minus 5 nanoseconds.
And then, and only then, you get this interchip calibration in the region of 2 to 3 pico seconds. And that's the only way to make it.
Yes, this is this, this is indeed exactly what we do in our testimony.
So we use one channel of the of each of the 8 groups with the with an external sideway form. So so this is exactly what we do.
But if you don't want to waste work to challenge that, the possibility that we are already ex it depends on what is the precision that you are.
You are looking for, of course.
Of course. Yeah. But the ninth trend is there on every d as chip.
So if you can commince Kyan again to modify the firmware and not to send the trigger to this 9 standard, but to send the clock to this line channel, then your problem would be solved without wasting a channel.
You're right, but I'm not so powerful.
So maybe I can try to make.
If we have to.
People issue that I had infinite power. This is not exactly correct.
Okay. In any case, we will see.
We have to bring some a good balloon to me.
Hmm!
So, Stefan, if I may ask just a short question. But if I use a Limo connector, so for this external trigger for triggering and feed this 100 Megahertz into analog trigger inputs is it the same effect, then.
I don't know how the time borders made I don't know if they have this Excel tractively going to the Channel, or if it goes through the Fpga.
I would have to see their schematics, which are never so so I don't know how it works internally.
You have to ask.
Okay, cool. Thank you. Okay. So at the very least, then we can expect a short manual hopefully in the short, you know, maybe we can applaud this to git.
Yeah.
I don't know, so just make it a repository so that people can't afford and save because I myself wasted weeks of time trying to reproduce, so make it better because I wanted to calibrate several boards and make something more generic and somehow it would be a it would
save me time if something like this was available. Maybe other people.
Yeah, I think if some time to make it, I'd be just that being unfortunate.
Okay.
Okay, thank you, Vincent. So I think we should move on.
And I saw that Luca is online. Look, how can you please?
Bye!
Yes, sorry. I just start sharing.
I think I think you should be able to see my screen.
Yes.
Hopefully it's gonna start. Okay? Alright. So yeah, thanks.
I wanted to thank thank Alexander for inviting us again to to give a an update on our activity, for on the on the digitizer asics and this is gonna be largely a follow-up to the to the talk that we gave last last October and basically
just updates on the various chips, and I apologize if there's some some replicated slides.
But I just wanted to make sure that the the context is, the context is, the context is clear.
So well, first of all, just to of, in case people are not.
I don't know where we at now our concentrated in building this waveform, didizer system on a chip where we basically do a a, a sample and hold a chip that also has digitization, capability and some and some some Dsp on board to to
offload some of the operations that would would need to be done.
For example, as in the Drs. 4 K's. On the on an external on an external device, and besides fabricating a chip, we're trying to do work some in integration in boards, and I'll show this at the end of the slide and with main application
in, and Php. Experiment are also trying to branch into.
We have a Project for Pt. Imaging and Plasma fusion, Diagnostics, and and some some other related the field.
The only other thing that they wanted to mention is that we are.
We have a collaboration in agreement with the with kind that has become our exclusive distributor for for North America.
So we will if anyone is interested in some of our chips or our evaluation boards for bench of testing, it is possible now to go to Kyan, and we we effectively are providing the board at the moment.
But we need to go through them in order to. In order to do this, this initial testing.
This is the list of the current by current basic projects I mean the projects for which we have.
We have Asic that are mature enough to be distributed to to potential users, and as you see in this, in this table, we are actually going through different types of sampling rays from the from the slower like around one giga, you get a sample, per second to the faster which are above 10
Giga sample per second. We have measured the different timing resolution from a minimum of 10 to a maximum of I mean to a, to a, to a, to like a 100 or a little bit over a 100 for the slower sampling rates, and also like large number of channels so for example.
HD sock the last version actually, we just got a Rev.
2 that will be will be tested. That contains 64, 64 channels.
Now I first want to to mention. I'll be very brief here, because effectively, there's a lot of the the previous talks are have been underlining this some of these advantages of the way from the digitization, and I will move on.
To describe some of the updates on the on, on a few chips that we described last time, and also on a couple of others that I don't think I had time to discuss now the the advantages of a digitizing architecture, at least from our point of view with respect to
more traditional way of extracting, timing, and charge, that using Tdc, or time over threshold is that we could potentially give a better estimates of overall charge because effectively, we know we know the entire waveform we the way for me information having more than one sample can help.
Us, in giving a, in giving a better timing, a timing resolution, as the previous talk, as a demonstrated with the Drs.
4 K's, mostly because it noise on the on the single point it becomes less important when you can actually sort of average the effect of multiple points and potentially, you can correct for a pileup and gain variation overall wonder of the signals the obviously there's a there's a disadvantage which is the
complexity, the additional design complexity is much higher, and but the good thing is that with modern technology, with the hire integration, we can really fit a lot of channels in in a single device.
So again, this is a slide. This is an old slide, so I don't want to dwell too much on it.
But the idea is that if we, if we use the same parameters that are typical for and for an Lapd readout, we actually can reasonably fit this into a into a small channel with a relatively smaller power power power envelope and a very simple monte carlo shows
that this can also give a given advantage in terms of in terms of timing reserve.
Now this is an overview of the typical architecture that we're using in our chip, where we have sampling cells.
This is a capacitor, array exactly like the Drs.
For that as a group of sampling cell at the input, and then periodically, groups of this and sampling cells are are copied into a still analog storage cells that that have their own containers, and on demand they individually region of the storage cell can be a can be digitized and then the process
by the rest of the chip, and here there's some parameters for some of the chips that I'm going to present.
So there's a the input cells, as in this case, are all 128.
But the number of storage cell can be varied.
Then mostly from the case of the arbark, is because we have a larger number of channels in the before.
There are 2. For who of these chips have 2 different approaches in the way that they are used? The Udc.
Was was meant was designed for slow rate experiments, and so effectively the way it works is that it fills up the entire.
Entire array ways for a waste, waste for a trigger when a trigger is issued, the entire ray of 4,096 sample purch.
There are 16 channels. New DC. Are are converted and stored inally, and then they can be retrieved, retrieve through a serial interface the other chips, which are probably more useful for some of the applications that were we're interested in here like the hardware to a continuous
acquisition, a kind of a streaming acquisition, streaming operation, because the triggering can be done externally, or via self trigger.
But after a triggering the the chip in time does the entire operation autonomously, and sends out the data.
The digitized data to to the outside world.
As soon as the data is ready, and there are mechanism in in our art to to make sure that we we are not. We don't.
We don't incurring high in hide that time.
Now, if if you more details on on some of the some of the chips that you see, this is actually a slide that really goes very well with some of the with the previous talking calibration, and shows it's also in this case, it is very important to do to do a proper
calibration of the voltages. Here you see that the black line shows a role, a role read of a new DC.
Of the entire array of a channel of Udc.
And and it's it's really, really noisy.
That's 35, more than 35 counts arems.
But after we apply the Calibration costs, that in this case are calculated not even not even with the with with a ramp, or with with more than 1 one sample, what we, just with a simple sample, we can actually reduce the overall the overall variation, with the with the below 1 point.
5 counts rms, and this is this is another view of the same thing.
Effectively. Here's the the pedestal, value, what we call the pedestal, which are the kids.
This calibration constant and after we do that, to the subtraction and pedestal value, the average standard deviation for the individual sample is between one and 1.5.
The other thing that we we are interested because, as I mentioned before, these chips actually have their own comparator.
And so they have much more sources of nonlinearity that purely sampling architectural, the Drs.
4? Have we? We need to correct, or at least to know what our linear range is?
And in the case of the Udc. The linear range, which is the range where, after a linear fit, gives a relatively small range in the in the residuals, is approximately between 0 point 3 and 0 point 8 volt.
The whole. The whole input range technical is between 0 point and 1.2 and one of the activity.
For we are trying to plan for a next version of the ship is trying to push this this range a little bit, more probably to the to the left here by by redesigning some of the some of the internal electronics in terms of analog bandwidth there are 2 types of measurements here
that have been done, one using a using tones and the other one using an fft, or a faster or a fast pulse.
They sure they pretty much agree. Please disregard this.
This word spike, because it was a narrowing in in Readout, and the overall 3 dB.
Point is around is around one Gigahertz, which is a little bit lower than what we expected, for the ship, and we are actually invested.
We know that we found a an issue about in the in the way that the input distribution was done, and in the Channel, and as well, we believe there are some contributions to the Board for this, but this will be as you as you'll see now their chips this is actually better.
For it can be, can be, can be, can be much better than this.
Another point which is pretty important channel timing evaluation for this ship.
With it, with it, some some experiments similar to the ones that were were shown before, in which we actually feed, a series of peaks with with known distances to different channels, and try to see what is the what is the jitter between channel and channel and by doing a correlation of waveform so it's slightly different
types of of of timing, of timing estimation that was shown before we get to a relatively low jitter around 10 picosecond or so for the for without any any further timing calibration, I will show with another chip that this is actually consistent with the
type of technology that is used. So our work uses the same under in 30 nanometer pretty much the same type of channel, and we found similar results.
The oh, sorry. So this this is duplicate of the same slides in terms of packaging this ship.
Actually can we actually use 2 packages, one with the 12 by 12 square that could take so all the possible interfaces, including a parallel interface.
But if we want to reduce the impact, the footprint of the chip, we can actually use the smaller 9 by 9 that uses only the serial interface, which is what was being as being used in the some of the denser board that we were making and the just to give you an idea, the actual
bare die is 5. It's around 5 by 5
So potentially. This could also be be reduced if it needed, by using some more advanced packaging techniques.
We identified a bunch of issues on Udc. V. One.
So the power consumption is not as low as we would like is a 35 milliwatt per channel.
We have a complete power model that is consistent with what we measure, and we know where to touch the power.
And so we're we'll be trying to do that.
In inversion in v. 2, and the bandwidth, as I mentioned, where we will try to get better, possibly by using an input stage buffer.
That shows a much better bandwidth in in the org v. 4.
And we also identified some artifacts of being started.
And I think we have some solutions for those.
So the the udc. For the applications that we're interested here is as advantage of being a relatively dense 16 channels in a 9 by 9 package and a relatively moderate power consumption.
But it cannot really suffer a high rate because of the way of the way it is.
It is built, moving on to the other, to the other chip, also in 130 nanometer.
This is the Rv. 3. It's it has a very similar channel, but there the extremal, the the digital control, is much more complicated and allows self triggering.
What we call Ouri mode, which is a patented mechanism by which, basically, we, we, we mark in individual portion of the storage array with the its own trigger.
And so we can use only we can digitize autonomously only those portion of the of the array to to save on bandwidth and to save on digitization time, and finally, we have a banking system that allows us to switch from portion storage ray to portion of storage
array, so that while 1 one event is being as being digitized, we we are not losing other other other events that might be piling up at the same time.
This is a picture of a board last time that I present.
We just got the the the new album before Chip.
This is a picture of a board where we incorporate the Rv.
The hour before. With this 8 channels shown here, some of the differences between the V.
3 is that this is an a channel device. We have an input buffer that should allow us to go to to around 2 gigahertz.
We have an internal pl to simplify the clock in the previous one require 2 or 3 different external clocks, and we extended.
We corrected some digital bugs, and we made sure that all the readout modes are orthogonal.
It can be all combined together. Some results, some initial results.
We just started doing some evaluation in the last couple of months in terms of timing calibration.
This is this time. Calibration is actually being made in a fairly similar way, as a once shown in the previous talk, we, instead of using a sine wave, who basically just using this this this fast pulse inputs.
But we're still using that. A crossing over a given threshold to estimate what is the the width of the individual of the individual interval.
And this is shown what is the width of the individual interval.
There is some, some stitching problem at the end of the of the array.
That shows why that explains why we have a why we have this this very large variation for the last sample.
The after we apply the correction for this, you can see that the initial distribution of for a for a pulse, to pulse distance, estimation, goes down to around a little bit over 1010 pico, second, which is consistent with what we did already with our v 3 in terms of bandwidth we did
try to estimate the bandwidth in a couple of different ways.
One way was just to to feed tones and see what the with the bandwidth is, and the other ways feeding a fast poulse and doing an fft of the polls both on a on a scope with a 2.5 gigahertz
bandwidth, and on the signal coming from our chip, and it's if you use these 2 mechanism, you can see that approximately the bandwidth is around between 1.8 and 2 giga, which is more or less what we expected.
This ringing is, is's is more or less what we expected. This ringing is A is being investigated, we believe is due to some subtle interference effects on the on the storage arrays.
So it's a and this is the reason why doesn't really show up in the with the signal, with the, with the single pulse, in terms of advantages and disadvantages of the artwork.
The artwork has self triggering, streaming capabilityilities can potentially go up to to high rate and has that time free operation and potentially can use a single reference clock.
But it has a higher power consumption. Right now we're around.
Actually, I can bring this down to around 60 milliwatt per channel with some fine tuning.
We just did, and a larger footprint the let me just.
We quickly go through another couple of chips that we have been working on.
This is actually not probably not very useful, for the lap.
P application, because it's too slow. The HD sock chips is A is a 64 channel meant to read out a cypm array, and the idea is that this is a very very dense readout where every channel effectively operates independently and autonomously and can and can and
can send the information potentially with some feature extraction on board of the chip to the outside world, and and these are these are the specifications for for for the for the version, 2 of the chip, which is a true 64 channel device.
So far we did. The we did tests on a 32 Channel device version.
It's there's a revision one that confirm more or less the the performance that we expected did the the reason why I brought this up here is that not not because this is neshly useful for the lap Pd read out as I said this is one giga
Sample per second, which is probably too slow for for operation, but for the, for the concept that allows us to to increase the the density of the individual ship and increase the amount of channel that can be serviced.
Finally, this is a, this is much more of the prototyping stage. We have this concept of a HP sock, which is a chip.
I didn't mention it here, but it's being done in in a more advanced technology.
65 nanometers, and the idea in this case was to target algae.
Pixel readout, so we wanted to be much faster, and we also wanted to have an in input Tia which is embedded in this particular.
In this particular device, via the the target structure here is that for the individual pixel can operate internally in extraction of charge and time, and potentially in on the same chip, you can do some data fusion that can that can merge information from multiple pixel to extract positioning
and timing information. The Channel architecture is slightly different. The previous one.
In this case we have only a single sampling array, so we can.
We can digitize only a short portion of our of of our I mean only up to 128 samples, but the advantage is that this saves a little bit in in power, and allows a relatively fast operation.
We still use a kind of a banking mechanism to avoid the to avoid the effect of a of that time, and we actually have a little chiplet that has been fabricated at 1.5 by 1
And right now we are designing a 4 Channel version as a stepping stone towards the full.
The full chip. So, concluding this, the ideal Asic, that we believe it could be very useful for an lapd readout merges a characteristic from all these other chips from Udc.
The dance, the possibility of having high density and moderate power from artwork.
All the capability of a autonomous and kind of almost streaming capability.
Potentially, if very high, density are is needed, can can borrow some, some, some lessons from the HP.
Sock. The last part of the to of today. I just want to mention that we, as as I said at the beginning, we are not only interested in fabricating the chips, we're trying to to make systems with them.
So we are, as I already presented last time we we we have 7 our works in a relatively old project to read out the genuine lappd called Hyper Project, with.
That shows a fairly good. The channel to channel even across across the board.
Timing resolution, the the have boards, smaller boards with couple of our works on it.
We have a larger board that we are now we have a we are being, we are being evaluating much more, using the Udc, so it's a 90 sign, a 96 Channel Board board readout.
And for other projects. Using an older device, but that could do a sampling at around 3 giga sample per second, the for it for another project, 8 of project.
We're actually doing 48 channel device that was meant mostly to read out a silicon silicon.
Pm. In in conclusions.
I want to just to summarize the say that we believe that way from digitizing can be a robust and flexible solutions for readout of high density.
Lap, Pd. And the and the current versions cover some of the Lapd specs that we are interested in covering in terms of the updates of today.
We believe that all these developments can have the potential to help a target, a delay.
Ppd. Rad out mostly by hybridizing the solution, by putting together some some features from any of these.
In one thing that we learned it is that for a there's not a perfect ship for any application we really need to kind of modularly put together things that that that that can work for the for the specific application and the also that optimize board integration is essential for leveraging the both the capabilities
of these readout ships, and the capabilities the old Ap.
Pds, and obviously we're looking forward to working with the community to try to develop a solution that is usable for for most people that are interested in this readouts.
And and this concludes my talk. Sorry I was a bit long.
Thank you, Luca. Let's see whether there are questions.
If not, I have 2 short ones, so first one is in the at least in the former times it was not so easy to get a evaluation boards from you, so do I write that recently the situation improved, and you actually descent.
I like hard work, base one to Jailup.
Yeah, I mean, it's right now for most of our evaluation board us to go through Kyan, and it should be possible to to get evaluation board pretty easily.
Oh, so now it is going through Kyan. Okay, I see.
But you can. I mean you can contact us directly, and we we we can handle that properly.
France! Please go ahead!
Yeah.
Yeah. Hi, can you hear me? Very nice presentation.
Thanks.
This is quite interesting. Maybe I missed it, but I'm trying, as far as I know, in terms of what you call rate.
None of the solutions you present would be able to cope with a basically, the 15 auto second structure at the Nhc.
Oh, really mistaken!
Yes, correct. I mean, we can't read that at at the 50 50 Nano second rate.
That is correct.
But the question is, do you really need to read everything at 15 Nano, second?
So. The the question is at the level of the individual chat, what is the rate at the individual chat level that if we need that that rate for the individual channel? Yes, I agree.
We? We can't cope with that.
Well, you know, there are gonna be some areas in some detectors which have let's call it sizeable occupancy. I didn't. Let's just say 10% to give a number.
So. Yes, you you don't need everything but you.
It. Well, you either need a long buffer.
All you need to read out quite fast and have a reasonably what do you call?
It I mean.
All. You can also reduce the window.
Yeah.
Yes, so we have a lot of different approaches to this.
So acquire less, same prosperity.
So the, for example, in the ag Sock, one thing that happens is that every channel user can use its own, every channel.
One thing I didn't mention here. Every these ships have a video discriminator at the for every individual channel that can mark the position of a signal that passes a trreshold, and that can be used to market position in the in the storage array for for digitization and
if that, if nothing is marked in a particular timing region, then the chip will not respond with, will not need to digitize, and will not need to respond with anything.
So this is mostly taking care of the low occupancy cases effectively in the case of very high occupancy, we can really go towards a a system like the Channel architecture, like the HP.
Sock, where we have a kind of a short, a short array, but that can be a can be converted at a fairly large, a fairly fast rate, so we could potentially convert as fast as one to 2.
Microseconds around that we can probably push it to around one microsecond.
So we could potentially get up to a one Megahertz rate with this type of architecture.
Okay, thank you. That's useful.
Thank you. French, Matthew, you've had a question.
Yeah.
So this looks really nice, and I particularly like the this concept you've shown of the hybrid ideal Ace taking the best of all worlds from multiple other systems.
As you probably know, we're in the process of getting an Eval board to use with our strip line Lappd for a test bed we're building in the Uk.
Underground. You said at the beginning that your Us.
Distributor now is can, and at the moment one of our us partners is arranging with for the Email Board.
But looking further in the future for a larger order than that for Europe, how would one go about ordering?
I don't know. Actually, if if Ezra is online today, at the moment he was, it was busy with another, with another.
Okay. So I'm not entirely sure what? What?
I don't see him.
What the actual plan I'm I know that is, I was looking into broader distribution, and I mean, for now I think we can, we can arrange things directly with the with nalo.
But obviously, if it's a if it's a fairly large order, we will have to something that will have to be arranged properly.
Okay. Sounds good. Thank you very much.
But yeah, .
Thanks.
We'll do. And we're looking forward to getting our email board. Thank you.
Okay, thank you, Luca. So I think we need to move on.
Okay. Thanks.
Federica, you are the next one.
Yes.
Yes, please. Go ahead.
Can you see it through screen? Okay, okay, so this is another application for the Lcb experiment.
The another a another application over the Lhpd.
And I will talk about the activities in Edinburgh and Federico.
The University of Edinburgh. So this is the outline of the talker.
So, first of all, I will give some motivation now to user for the upgrade to reach the sub-dectctor.
The lapd, and then we'll talk about the Edinburgh setup and some program Lapd measurement that we did, and some measurements so that we have to do.
Then I will show some some results in particular. The first gain that are great study and the daytime resolution the ultimate time resolution studies is still obserina improving, but I will show you a measurement that we did so in progress. But I will show you a measurement that that would be the measurements that we did so
far well, first of all, just to present a bit the application of the laptop for the upgrade at the moment there is a an upgrade, one ongoing for the Lsb.
And basically, it's a brand new director. But at the moment is is second data.
At the moment we are taking data, and and we are also working on, what are they are in defense for?
The upgrade. To that we will see the you see here, basically for the upgrade to.
We foresee an increase of the luminosity of 5, 6 times.
So this means that will be a really a really challenging environmental in particular, for the photon detectors over the reach.
Some that subdectors that you can see here. It's there, is a there is there, each one, and the reach 2 in the layout of the experiment.
So basically, the main strategy is to add the timing information to the Richard sub detector and to reduce the pixel size these these are these plots from our simulation.
Now for the current upgrade, just to show you that, for example, if we take today, it to map the equipency of the rich one in the separate region, we foresee already for the upgrade.
One a pick over the Cubancy, nearly over about 35, 40%.
This means that if we foresee a increase of the luminosity or integrated terminosity of 5, 6 times, this means that we would reach 100% of the Qancy during the upgrade to so it said the possible solution will be that time read out for the route so directors
you can see here, for example, it's a a simulation similar to this one.
If we take a time, float to one a second, we are not able to distinguish the the rings, the the drinks of the richer detector, and if we did as a lot to 100 people, second, we are able to distinguish this, this, so that's the reason why
we are considering at the moment the different technologies for the in particular to other timing information, for for for the reach.
So basically these are, these are the main technologies that that are considered for for the future.
So other groups are testing that is again so. And also also they, the Ma.
Pmts. Will be would be considered that this this is a technology.
That is used right now at the moment, but for the future probably we foresee to to improve this design mit pm, piece technology, anyway, the A Mcp based solution at the moment is is also the one that
is considered, and in particular we are testing all the delay. Pd.
In in the lab. We know in Edinburgh.
So basically we have the. So we all know that the advantage of the the advantage of the Lppd is a really low time resolution.
That's the reason why we are really interested in in in this technology.
So basically we we are, we have a generation, generation generation to lap.
Pd in Aidra since late 2021.
We have a Dlpd 97 that you can see here in in this pictures.
This is a different side. And the back side, basically, the moment we, we still have this Readout board directly provided by incommodate usual one with the depict sites of about a depict of size of a 25 pitch to pitch, so I would show some some
somebody's also obtained with. With this readout.
So basically this is a list of the program. Lipd measurements and some measurements that we did with the real Pd, 97 in the lab, in any work.
So at the beginning of course, we tested the.
We checked the Hv. And current trends to be sure that the current absorption, the leakage car and towards them they wanted that to also income.
So you know, you know there are the reports.
So before the shipment, just to be sure that the detector was working properly also in our setup, done with the from the other count study, and as soon as we put in place a last source procedure, we measured the gain and the gain was extracted that the
measurement of the gain was a strategy with a decain digitizer.
That was a user, that it is a it's a the ken digitizer. But the desktop one with a with the 16 channels.
So basically always there, there's for cheaper based the technology.
And for the time reservation. I will show some some results.
But this time obtained with the a duct obtained with the with the about 22 of up to 20 giga giggles and a digit rate up to 128 to
at the moment the current plan is is to basically we are designing in Edinburgh our custom pixelated board to improve the special resolution.
So to low the size, down to 3 and there are some partners, but also that we are.
We are studying, but I will show you later, and another another feature plan now is the quantum efficiency study.
So basically this is the the setup that we have the delay.
Out of the setup that we are in a Edinburgh. Here you can see in the dark box we have the Lapd.
On the support. And we basically connected to to desktop Hb supplies.
And in the dark box. We have also aiser mount on stages, stages that that that allow the displacement of the laser and it's it's a it's a it's a fibera coupled.
And we basically basically, the lies are the laser driver is a typical laser.
If you go quant laser with the a wavelength of 470 nanometer, and we departs with over with a maximum of 70 people are going to.
We use the synchronization output over the laser this can digitizer that I said before, for the gain studies or for the timing study.
So, the scope. So these are.
These are some pictures of over our setup.
This is the very first picture. Really, you can see that today some cables are not a Tach days.
Just it's just to show you the the distance setup that we have.
So basically the this is, delay, delay. Pd, and we have the laser mounted here on state.
This are on. These are the stages in a that allows the yeah.
The displacement next next, and Y, and then outside the dark box.
We have both the digitizer can and supply, or the oscilloscope, the tools for the determining studies.
So basically at the beginning with the form, though kind of a comparison between now the Dick's current to be measured in the lab, and they were not provided by income and the we observed quite, we were observed to acquire an agreement between now between the
measurement, and and yeah, it's a just to show you that it's a the trend that that was already foreseen by by in coma changing.
Now they defaultance of of the and A, the devolved interpreter for the Ncp.
Go in to the measurements that we did in Edinburgh.
As I said, the game studies again, studies and data count studies were performed with the decay digitizer with the did simply rate over 5 giga sampling per second.
And yet you can see an example of the accounts. This these are, of course, these are number of sample blocks that are moving the visa over a 200 ms.
If we consider that so basically, we performed this study for for the direct rate versus the photocopy voltage for a fixing our Dncp voltage to 850 volt.
And it's it's a day the same.
It was an agreement with the studies that were performed by in coma before the shipment.
Then we switch to yeah to use them.
The laser, and here you can see a a signal of a signal.
Acquire the always with with the again. It's a single photon.
And it's that these are plus minus one meal volt, basically, then we extracted the the trend of the gain in in number of photon electronons. Of course.
So that's the Ncp. Voltage, and it's it was the trend expected this one was obtain this a trend was obtained.
The center of fixing the photocopy voltage at 100 volt.
And the one big thing.
Then talking about the time resolution, we extract.
It is a time resolution using Aiza kite with a simply rate of 120 giga sample per second, which means that if we consider this plot, this is a number of sample bodies are it each sample is a less.
There is each sample is a less. The resolution for a rich sample is less than 8.
So, yeah, you can see an enormous difference.
So a huge difference between between now the signal showed before basically what we are doing now with a withd signal is a updated, you know, an online digital subtraction.
Considering other, the first 200 sample just to center in in 0, the pedestrian, then well, considering the time of the signal, or performing performing negotiation fee, though, and taking the mean as a reference
for for the dying of the signal. We don't accept the time resolution, considering the difference taking into account today's education output of the laser.
So they the laser trigger. Basically. So this is of the time of the signal, minus the time reference provided by by directly by the synchronization output of the trigger.
And we then perform another, another, another g. Ocean feature, and we extract the basically the sigma of these distribution is our time.
Distribution is our time distribution is our time, distribution.
So here I'm I am requesting the the start.
With the within a single photon electron condition, with a Lser frequency over 5 kilohertz and the fixing the Ncp.
12 thirds at 860 volts. Yeah, you can see that we did that.
A kind of a photo photo of the voltage scan.
So so studying the Time reservation versus the photocopy of Voltage.
Here you can see that we we can. We can reach for photocopy voltage up to 400 doubles that we can reach 82 picoseconds but this is still not corrected, but these are these are pointed.
Read, it's still not corrected by the the, the, the uncertainties of the introduced by the laser.
This is a the point corrected by the full, weighted dark maximum of our laser.
So talking about the plans that we have in Edinburgh at the moment, I said, that we are using as a readout board the the usual border from from in coma with a 25 pitch, and now the design is ongoing to
to ever a new customer customer. Pixelated board decreasing the the size of the size of of of the pixel down Ebina, a pitch of 3 or, for example, we are considering also some other ideas for the for the partner for
example, we could, instead of over in 64 picks, I'll say to by 8 pixels with a picture of 3
We can, for example, considering to ever to study 8 by 8 pixels with a pitch of 2 or, for example, 8 by 4 pixels, so with a picture of 2 by 4 to have rectangular pixel so this is a a working progress and our goal, our AIM
for a day this year is to bring. These are, the plan is to bring in in autumn the laptopd on Beim, basically with this new custom board that we are designing, and we will produce.
We can couple of them our device with the a duct chain made up of some facilities, board, epic, Ddc and Lapgbt.
Basically these are. This is a decorrent plan for the the reach readout for for the next test beam.
So, in conclusion, we are already studying. This is a still.
This is already an end phase for the Lsb upgrade to, and we are considering as an application for the lap.
Pd. They reach the Reach photon detector. So that is, they did reaches the subdivor of the of the of Ncb.
We have, the tie. Ltpd.
97 in Thera in the lab that is currently in the deskt, are currently ongoing, and we extracted the first promising results.
So as a show do in agreement with those extracted by email we were extracting in particular, the We did a kind of that council study so, and our gain studies, and we extracted the the time resolution.
But also studies to achieve the ultimate time.
Resolution is a study, is still ongoing.
In parallel. We are designed with a custom board. The group is designing this custom board, and we hope to bring the Lapd.
97 on Bima, with this new board, 187. So thanks a lot for the opportunity.
Thank you for the questions.
Mark.
When do you think the new board or the first new board will be ready for you?
Well we for see as a schedule, we don't have a fixed schedule at the moment, but we plan to have a first of the type of this board in May to to start the the test.
If with a kind of integrated with with with a kind of a integrated board.
Let's say to have a kind of readout, you know.
In a sense we will, we will read out to these these pixels, still with the Dsm.
Connector. So we need the yeah to have a kind of integration board.
And yeah, in May in May, we will start today. The test.
And then in some September of October, we will bring.
Okay, he'll be interested to hear the results in May and June.
Yeah, I will let you know.
Okay. Thanks.
Mark while you are online. So for the 97 is 86 s, something which would be expect.
I have also the that was a, you know, brought in the backups right?
So I put this is the plot in in the report.
And basically you, yeah, you have to consider. These are 8,850.
So these are this point with a 120.
So when we made this measurement, actually, we were using the laser that we have this laser in a very bright mode, which means that it, the laser light can be on for like a 150 nanoseconds, even though most of the light is coming out in some like 20
picoseconds full with fmax. There's still plenty of light bulbs coming and I think that's the reason that we get such a large time variation.
So if if we had this back we would alright measure with a dimmer one, which is more Gaussian at 60 picoseconds with half Max.
Okay, thank you. So one thing I wanted to say is that several groups by now built actually, these pixelated boards.
Yeah.
For like summer, who is online, I think. So. Misha built one with Saveria recently.
So there are a few popular, not mistakes, but a few things to to keep in mind.
If you want, you may want to contact the guys and ask them some questions.
So maybe share the designs just to avoid, like crosstalk and reflections and things like that, just to save you time on iterating. Maybe.
Okay.
Who is the second person you mentioned?
So Mikael Osipianco may be still online.
Where I see.
Who built such a board just recently. I mean, we can take this offline.
Yeah, okay, that's 6 is offline.
So if you send me. Yes, okay, welcome. Okay, thank you for the rico.
I don't see any other questions, so we have still 2 more talks. Rob.
You must be the next one, right?
Yeah, can you? Is that one?
Yes, please. Go ahead.
Okay. As so Hi, everyone, I'm Rob. I'm a Phd.
Student at the University of Sheffield, and I'll be talking about some of the activities with Ipd as we've been doing a Sheffield specifically focusing on this technique for multi photon reconstruction on the generation one strip line Lapds
so I'm just to start off the Uk.
Is really increasing its involvement with with. We have 2 of these Gen.
One strip lines. Only people in Sheffield one of which we've learned out to work university so they can develop their own test, stand one.
You just saw from Federica, at Edinburgh, and there's also a second Gen.
2 Lapd at Glasgow that arrive fairly recently, and so the Uk studies are focusing on the characterization, as you saw in the previous talk at the moment.
But the Sheffield in particular are also gonna be, are also sort of for developing for use in as well.
So the motivation for this multi photon stuff that we're talking about is that's, I think, Matthew Mike sort of briefly mentioned that we're building this 30 Tonne water rank of the sector at Bolby underground Lab in the Uk it's gonna be very
similar to any idea I guess. And it's, you know, similar similar size.
And using this just more tank off detection and any sort of detectors we want to really precisely reconstruct every photon.
So we can get the best reconstruction of the event.
Vertex, but on the strip line, if you did especially, this becomes really challenging.
The more photons you add to the to the events you get. This problem.
But my! What's Dean briefly mentioned in in his talk about dissembiguating all these signals and trying to figure out which signals came from which photon, and so ideally, we want to have some kind of algorithm that can reconstruct
photo hits on the lapd face like a range of photo occupancy is from from the single photon level up to you know.
Maybe a 100 or so photons. And this becomes even more important as we potentially move from pure waterfall detectors to liquid scintillator or or water.
Basically anything with a high light yields. You can run into these problems pretty quickly.
And so just talk through the this. We have these 2.
As for planning Pbds and talkbox, we're using this.
The same can. Dr. S. 4. Based digitizer.
It seems like, basically everyone's using. So I was very interested to hear about the talk on that.
The calibrating these, these chips definitely, that into account.
And we've been following our own sort of characterization of Pbds like the gain and Doc and that sort of stuff.
But one of the things I've been using is using this app to inform simulations which I've been using to help sort of characterize this this reconstruction algorithm that I've mentioned.
And so the results from the the characterizations are being put directly into these.
These simulations. And so what I've been developing is this, this waveform simulator that allows me to take a simulated events in this case, I've been using rough packages.
Jump 4 based, simulation, toolkit and so to simulate liquid synthesiser events with all with the Lpd geometry. This old 20 by 20 cm square, and this gives me a bunch of photon positions and times the simulation then smears
with the appropriate time the time spreads and charge distributions, and I can then use these.
This Monty color information to then afterwards produce, produce waveforms like produce, a simulated lapd response to to that event, and so it has a very basic model of child sharing involved.
But no cross talk. And basically each photon the responsibility for each photon is just stack together at the end to produce the sort of total you know the total response of the Lpdcs from a given event and noise is also added to make things be more realistic so to show well.
I'm discussing. This is kind of a these are the 28 strip lines, and then, you know, 209 s, dearest, for accession window.
And this is like a single photon events. And so you can see that you get like the charge sharing across a couple of strips and and you can see that, you know, it's slightly closer to this neighboring strip than this neighboring strip cause pulls us higher and you can sendroid.
And find the position. And if you add the noise, it looks a bit more realistic, and then, if you look at the individual strip line, you get the sort of characteristic lipd shape pulse with the fast rise time, and oh, and a second wide or so and so this is the sort of basic
waveform signal that I've developed, and that if you look at multi photon events, you start to see, the kind of problem that you have in this.
What trunk of experience with these multi-photes hits is that you get this sort of response and this I think this is just 5 photons in this.
In this simulated event, and you have to start to figure out, okay, where did the photons actually hit on here?
So we wanna have some kind of algorithm that can take a an input like this response from the Ipd and actually try and figure out where the photons struck on the Ltp phase as you add noise.
This gets more and more challenging.
So the method I'm following is is follows very closely on from a paper that Glenn Jocker and and others row a few years ago.
Now, and I'm kind of trying to revive it and see how how appropriate it'd be for use and and button, and maybe other water trunk or experiments.
And this idea of using this deconvolution based, approach where you have some template waveform which is shown on on the right here of like basically a single photon response of the onlypd, and you then use this as kind of like a point spread function to go
and deconvolve the entire Lapd response.
With this template, and this should hopefully hopefully help you disambiguate and separate out individual photon hits from the sort of mass of peaks that you get from a multi-foton event.
And so for real data, this would be some average, you know, like, like an average of thousands of single thought on, I'll single waveforms for the simulated day are all the way for us to proceed using a functional form that I know so I can just sort of reproduce it in a
and it's from the simulation data which is obviously absorbed.
Best case scenario. And that's why I'm gonna be sort of showing today. It's just ready to the best case scenario.
So as an example. Here we have. You know you have both sides of the strip line that you read out.
This is an event with sort of 5 hits, so you can see quite clearly obviously looking at event like this.
It's quite simple to see whether photons hip!
As you add more and more, it becomes more and more challenging.
As an example. So we have these 5 hits on the left and right side, and then you perform a deconvolution.
This shows like on a single strip, what the deconvolution actually performs and the oranges after the convolution and you sort of maintain all the sort of characteristic of the post you maintain the fast rise time, so you can still get good timing off it. But you're really
flattened. All of the noise on, on the strip and you can kind of see in the heat maps that you know you get all this sort of like checkerboard pattern here from the noise, and not really.
It's always fun, and then you have a really easy time finding every peak just using some kind of local maximum finder, and then you find your 5 peaks really simply.
And because we're working on the strip lines you got, you have the extra challenge of not only do you have to, you know deep convolve and find your peaks, but you have to actually match up your peaks and you're left to right side, which again, in this case, it's
fairly simple. You can kind of look at each one, and just kind of judge, but as you add more and more, this becomes really quite complicated, and so again, you want to have some kind of algorithmic way of doing this.
And we do this using the solve likelihood based approach where you know this well.
So every peak that you find has some exposition which is still at the time in the acquisition window, some Y position which is itself, which strip its on its voltage value.
So HP. Can be described by these 3 values, and then using this, you can kind of creates likelihoods, to judge from a selection of lay peaks and a selection of right peaks on each side of the LGBT how likely those peaks are to be correlated with
each other for a single photon event.
Basically. And so the Pdf should be, I think, fairly intuitive.
The strips have some characteristic signal propagation belong velocity.
And so you know that if you're if a left speaker, right peak is separate in the acquisition window by more than the time of it takes to travel the entire strip, and there's very little chance they're gonna be from the same origin.
But obviously they have a much greater chance if they're within that time.
Window, and then like, and then likewise in a similar way, the the closer they are in position, the closer they are in amplitude on the left and right sides of the strip line, the more likely those peaks are to have originated from the same original original photon so basically you
can create some. So matrix of your left peaks and on your right peaks, and you can just go down, picking the maximum likelihood value until you've matched up all your peaks, or until the light it's too low and they you have some unmatched so much
peak, and then, once you've done that, you can then actually before we are reconstructions, actually find the X and Y, and then time in the on the Lfp itself, and for the strip lines, you know the exposition you've just which is sort of a longest
trip line you just find by taking a difference from the left and right peak time I use some constant fraction discriminator.
I think about 25% polls high or something.
And then across strip line. You can just centroid across a few neighboring strips, and I guess you know what position.
And then a time. I take the average of the left and right times that I found from the original position, calculation on the constant fraction, discriminator.
And so what I've done that is sort of simulate a few different scenarios.
So this sort of single photon scenario, so obviously with a single photon, you're in the easiest case, and you get very, very good.
So good resolution. Few millimeters, and why? It's less than a millimeter and I have this efficiency as well.
As, how how many photons do you actually reconstruct versus how many you see?
And it's basically a 100% for the single photons.
And then the real challenge comes when you add more and more photons.
How do these resolutions degrade? And you can see that you kind of expect that your X and Y resolution of the reconstructed photon position on the Ltpd gets worse and worse, as you add more and more photons the time resolution also degrades because you're this is the sort of the
same photon time resolution, I guess of the you know you're comparing the Mc Photon time to the to the reconstructed time.
So you know, typically, you just like the time resolution to decrease as you get your sort of route event thing.
But you know we're not reconstructing, plus the times here.
It's just it's the Mc. Photon time.
And most importantly, you actually lose a ton of efficiency as you increase your photon.
So by the time you get to 100 photons only actually reconstructing about 30.
So this is very much the only work in progress. There's definitely, I think, work that can be done to to improve this as law fine tuning that can be done in the in the deconvolution process.
But then just a show kind of example of a 100 photon event it might be hard to see his team at the top.
But so this is a liquid synthair event, where I've you know, created a 100 photons from licenses.
And because it's because of the properties of Sinclair.
Most of the hits happen in a very short amount of time, and you get a few hits in the tail as well.
So this guy shows you the challenge that you already have is that you get this kind of mess of the heat map.
And you have to try and figure out where the photons actually struck.
And so on. Here we have the time and the acquisition window and the vertical position on the Ipd.
And you can see that when the photons, the blue dots, are the Mc Photons, and their crosses are where they're reconstructed.
You can see that when they're nicely separate in time, you basically reconstruct perfectly but as you cluster more and more hits together, you start to just sort of reconstruct the the clusters rather than the individual hits as the disambiguation starts to fail when the pulses of
this close together, and now on here you have the actual real X and Y position where it's been reconstructed, where the photons actually work.
So this is kind of been a quick, quick summary of the so sort of algorithm that I've been working on for these multi photon events.
The reconstruction actually was quite nicely, in most sort of lower first occupancy scenarios.
I'm still not certain sort of detectors like Annie, and like the one being developed a bulb.
How many photons we really expect to see a typical event on an Ltpd cause I'll definitely help to inform what this the direction this algorithm gets developed in and we see this sort of decreasing efficiency for the resolution.
Well, the decrease, the performance of the rest of the reconstruction.
As you add, normal photons, as you'd expect I'm currently working this 5 giga sample sample right?
Based on Drs. 4. But we know we may move to other other potential digitizers like the Psac, that any users 10 gig examples, and we saw the talk from about that digitizes as well.
And so maybe higher sample rates might help more. With this.
And I'd also like in the future to sort of do a similar test.
But with the pixel analogypd, to see whether we even need this algorithm at all.
If we have the Gen. 2 and we, you know, use pixels rather than rather than strip lines.
But that's yeah. That's the end of my talk. So thank you.
Thank you, Rob, that's interesting. So well, other people are waiting.
So this last line here, you don't necessarily need to use German tomb.
So in principle, you can use something called Hrpp, d DC.
Coupled, which is also, and there is no windows signal there, right?
But what I also think is that if I were exercised with tech drum succeeds, and one can shape, they are not.
Wait up in some, you know, in almost debitory way, customized for a particular experiment.
So this also can be of interest, because, instead of pixels in principle, you can have shorter strips, and then somehow, all your machinery would apply.
But the Channel count will be much smaller than in a pixelated case, but if you see that your coupons is not is too high for full lengths, strips so one can probably cut them in in in pieces, and increase the channel count only like 2 3 times but reduce the effective
occupancy to the, to the limit which is needed.
Okay, yeah, that's really interesting.
Well, Mark.
Rob? Are are you planning to?
Yes, okay, go ahead. I thought you were muted. Okay.
Are you planning to try testing your reconstruction?
While you say, using 2 lasers with fibers or something to deliberately put photons at home locations on a I'll strip line and then see if you can reconstruct it.
That would be a great test. Yeah, so this is, yeah, this is all simulated.
I forgot to mention that. Yeah, I would love to do some tests with the real.
You know, real real data. Yeah, I would love to do that.
I just haven't quite figured out how yet I know.
I think when I was at the income workshop we had a brief look into doing something similar.
But yeah, I I I figure out how to set up that experiment.
Yeah, I, think we yeah.
I think you can use a splitter. It would be cheaper.
Yeah, it is what I would like to do. Yeah.
Yup!
Okay, thank you, Mark, and thank you. Rob. I don't see any other questions.
So now our last presentations presentation on the agenda.
Rory, please.
Bring your slides.
Online.
Okay, hopefully, you can all see this screen. Okay?
Yes, please. Go ahead.
Great, so Hi! I'm Rory. I'm Phd.
Student, university of work, amazing work in the Annie Experiment.
So what this is pretty much an overall summary of, or an overview of, the independent dark box setup, for we have set over a phoneilab with an lappd and the overall software that goes into analyzing the data
that comes out of it.
So just start off with the experimental setup. So we use the the Anni Psac electronics.
So each lapd is read out by 2 A/C. DC.
Cards, and this the process that each lapp goes through before it is deployed.
Each goes through before it is deployed.
Each of these aggregate cards has 5. These PC.
Chips with 6 Channel coach, chip with each of the channels, digitizing away form.
Is run out to an A/C. Cards, which also does some other magic which then sends it on to raspberry pi, or any other computer, really doesn't have to be that for storage.
So we've got this schematic. If the data flow in the in our darkroom setup.
So we have our Lppd. On the Ipvd.
To these Acds, and those are physically attached to the back of it, as well as this trigger board.
So the trigger board can be used when it's running, in is self triggering mode.
Otherwise it's not used. But buttering mode is how it's used when it'll be deployed in the experiment, but that we don't have to use it that way in the dark room.
An external trigger, which is just pulse generator, sending signals to a pickup board.
It also sends smoke signals. It sends fake beam gates to the A/C.
When that's high, then we can take data. It also drives our picosecond laser, which is in the dialog box with it as a step.
4 of that sort of goes through to this raspberry pi, which runs the entire data acquisition sort of operation.
So that's how we collect all our data. Really.
Analyzing. It is so split into a few different broad steps.
So this is all it implemented with the tool analysis software has been saved framework there which is obscured by the logo, but that this is the the software that Annie uses for pretty much everything certainly analysis related and much of the other software as well.
So first of all, the data is go through some pre-processing which is passing the raw data that can take a few different forms depending on which way we would like to store the data.
It can be stored as rural Ascii, or it can be stored as in a binary format, and the society definitely had reading both of those in.
We subtract any of the pedestal values which are to do with the Psac chip.
It. Time aligns with signals, and then it subtracts the baseline from the waveforms itself.
Does that by fitting a well, taking a histogram of all the values in the way form fitting a Gaussian to that, and then subtracting that from the entire waveform and then it goes through this simple pulse, analysis still the best way to see what it is but it
finds pulses in the roll way, forms just for the time over threshold. Method.
You can adjust parts of that within.
The analysis sort of configuration files before you run it, and it'll save all of those.
There's also a filtered pulse analysis.
Which is a slightly more complex technique of forming a fast Fourier transform of the signals to remove any high frequency noise, and then it also identifies pulses with a constant fraction.
Discrimination, method rather than a time of a threshold. Method.
All of this is saved. Between all of these as well, there is some clustering which goes on to try and resolve to individual photon hits, so as well as the polls data there is being saved.
There are data saved on these hits themselves, and also on the larger scale of sort of times of each event, and then also down to final levels of rather than just a polls. But also just strip lines and any other thing we want and this was just a.
So this is an example of some of the outputs.
The we can look at. So this is from L 63 before it sort of went in.
But this. These were some voltage scans that we took so pulsize just one of the variables we can take, and so this is our dimensionless gain, variable.
I think, unless it's gone. Lost. Okay? Yeah. So I did.
Haven't another slide showing one of the other variables, but that seems I seem to put the wrong one.
But we've got the poll site. We can also use the maximum aptitude in which is in terms of an actual charge, and these are more of these sort of pulse related variables.
I was talking about what's going to hit variables, and you can also look at individual strip lines or across the whole lap as well.
So it's a few sort of, I guess. Yeah, useful takeaways from this also.
Next steps that could go onto it. But first and foremost the Annie Lapd test stand is great for training newcomers and new students to the eye experiment and utilitarian case.
In point, Big. I now know slightly more. After working with this test stand, then, I did before.
We can also use this as a as a base for analyzing the data that will be coming out.
The increasing amount of data that'll be coming out of Avani's deployed Lapd system that will involve changing from the output formats to match the overwhelming data for data structures.
Hip building from type data as opposed to laser data with. And that'll involve.
Complicated process which I'm sure you've had loads about and integrating the information with the other subsystems. So the pnt's and they are arranged to to in order to get some useful physics results and really leverage their potential.
And finally, this is also replicated. The annual expertise and lessons learned to bring back with me to the Uk.
Into work with the test sound that we're setting up here, which is, can be phenomenally useful.
I'm doing. So. Yeah, that was just a short, short, short summary of what we got down there.
And Yup any questions.
Thank you, Robin. So since we start having more and more of this data, analysis talks, calibration.
So, maybe so, somebody takes care to create a shared repository where people can post pieces of code.
So that everybody could make use of them, not only in the Uk, but elsewhere.
Look up, please welcome!
Yes. Thanks. Yeah. The question about the yeah, exactly.
The calibration procedure you the you say that the second step to be making this after the first row, cut where you are identifying the pulses, is basically doing an fft.
Of the signal doing a assume, probably a using some form of low pass filtering, and then going back to the time domain.
Did you try to analyze to see what happens to some of the some of the phasing information that you lose with that?
Because the signal you're looking at this is pretty fast, anyway.
So there's the risky are actually disturbing a little bit the phases of the component that my might have an importance in the in in destination of timing so I'm wondering whether you had the you had a way of analyzing and fine tuning that filter that
you're using.
Yeah.
That's a great question. So I almost wanted to ask the same.
What is the answer?
Yeah, that is a good question. And I don't know.
Yeah. Love. Yeah.
Yeah, that's a good question. And I don't know the answer.
Yeah.
I mean, you have all the machinery. So I think that you probably can change the parameters of the filter, and and also use no filter at all, and then see what is the you're probably going to have a best possible bandwidth or to consider right that will give you
the best results. That's gonna be interesting. I think.
Yeah, yeah, thank you. Yeah, I'll definitely look into that.
Indicated in his talk of Sorry. Go ahead!
Okay. So Rob showed in his, in his talk that the the leading edge is kind of the same, I mean has the same slope half time after the same fft.
If I understand character, it was. What was that Wiener Filter?
I think, which is pretty much the same. A 50 back and forth into the time domain, and somehow the pulse looked the same.
So maybe it's not. It's not a problem.
It my experience. I took quite a lot of fine tuning to find the the right sort of yeah.
The right filtering it doesn't just destroy the post completely.
So I'm sure if yeah, before we look through some.
So iterate over a few different forms of the fft filter.
Then there will be some optimum.
Other questions.
I don't see any. Thank you, Rory, are the topics to discuss.
So, then don't let me thank everybody who was present, and especially everybody who contributed with the talks.
I think we stick to the same scheme, to the same periodicity, and have the next.
The next workshop in half a year from now.
So one thing I wanted to mention is that we did set up this lapd mailing list, and there was not that much traffic.
If at all, in the last half a year. But in principle, if people have, if anything, to share, so don't be shy to whom to post to this mailing list, and so that everybody knows what's going on, so that we have more exchanges than once every every half a year.
Awesome. Yup.
Alexander. This is Mike Foley. I recall in the last one, or maybe even in the first one, that getting all of the users together to help, maybe fine tune or tweak or lead us in a direction to a unified design, so it could be
used across many different avenues in here, in different projects, and I didn't know we were still talking about strip line.
We're still talking, you know, capacity couples.
And now we have the Hrppd coming in with both capacity, coupled, and we're, as you know, we've been doing a lot of design work trying to find tune the next generation of directly coupled.
So any overall comments toward that end of trying to unify a design, or at least get it down to something that's only one or 2 ones, sort of, say, 4.
But I don't actually see this happening because the applications are pretty different.
So in some cases you want to minimize the channel.
Count, for instance, and at the same time don't lose the special resolution, and if your occupancy is small, then of course, the capacity will be coupled design is the way to go if you don't want to stick to the strip line, of course, so, if you want to have something pixelated
so, if your application, like in Book of York, assumes very high occupancies per event, there is no other way other than to go to very small, very fine pixelation, and DC.
Coupled, one I don't know. So general design, principle principles, of course, can be the same.
So like where to put high voltage connections and things like that.
But so I think the more people, you know, once once we have a design, so we can post it.
And then tell people on this list that this particular modification is going to be produced.
Let's say in this quantity, and if somebody has, you know, says something to say.
So then people say.
And as a commercial supplier of this, it's it's good for us to to know these things because we can't be all devices and sensors to all people, and you know we certainly like to streamline our fabrication process as well as
be accommodating to some things like that.
So I appreciate that answer.
Even if we can't.
Yeah, if I can add something.
Oh, sure!
Well, first of all, this effort of unifying what is needed is done within.
Because we have now a well-defined project.
Maybe it's a sub project inside our detector, maybe a second one, and we are trying to request the same specification.
This is our current effort concer concerning the more wide community.
I would imagine that desk still be application, which are much more confable with capacity, coupled, pixelized planes.
But it's Alexander underlined the.
The differences between these 2 devices can be kept limited.
And in particular, after that one is developed up to the end, and becomes the used on a large scale in an experiment that this will also have a driving meaning within the community.
Oh, Craig, thank you. Sit down.
Yeah, I mean, I just wanna sort of make an analogy to the technology has been around for 60 years or so.
That's sort of multiplier tubes, which you know, when they first came out with course they were, and all sizes and shapes that we were just.
Developed what eventually, you know, kind of midterm along the way there were certain, you know, standard sizes, I mean, everybody, of course, wants a detector that's optimized to their own particular experiment.
Just like we talked about to like one ship that fits all needs.
So they're always going to be some customization. But I think you know the the way to think of it is come up with a few compatible with common.
Standard sizes that you could make it so.
One size isn't enough at all. That's pretty clear, but start off with a few that then people take that is more or less the strain, unless they're willing to spend a lot of money for development, and then they design their experiment around that I mean rather than the other way.
Around, designing the detector around the experiment. They say.
Well, they come in 10 cm square is 20 cm square, but maybe something in between basically, all those same or similar properties.
But then people realize that's what they have to design. Experiment around.
But you know good well, fine, too tubes evolved for a long time, and now you can get them.
In all sizes. But this is, which earlier in the design, but I think I would think, starting with a few, get a consensus that we would.
The optimal sizes may be, and starting with one or 2 and see if people can work with that.
Excellent point. Craig, and you know, as we've seen here at income, the internal strip line is really only found.
A couple of homes and the community, and most shown even here, has been leaning toward the capacity, coupled version of the lap. Pd.
So the smaller Hr Vpd. Capacity, coupled is there relatively, should be more or less the same, although focusing on the smaller P. M.
Cps. But the exciting news is gonna be when we can start doing these directly coupled.
Oh, and I'll soon get that moving, you know. The fifth factor comes through and then we can make these things and show how they work and be able to tile them together and hook up the proper electronics with certain readout boards as
Alexander was showing. I mean, that's the next exciting thing for us.
Well, I think that if we succeed with this exercise, with Tethra and standardized things like high voltage connections, and, you know, optimize the active area and demonstrate that one can build custom Arab based plates and have reliable interface to to the external asic board so this
would be already enough, or pretty much enough, for any other experiment. Like, like, Yeah, I seen to use the same optimized sensor. But just customize the the base plate and the PCB.
We have a challenge ahead of us. That's for sure.
And of course, which might not be so obvious to the end user.
But the mic follow is well aware internally, here, at any we are consolidating that skews, if you will.
We're working very hard to transition away from glass towards Ceramic.
Like well ceramic tiles, ceramic is more challenging from a ceiling point of view because of the cte differences.
But as Lexi showed this morning, we're making excellent progress in that and over time, all these ceramic.
We're also moving away from Borough silicate windows to, you know, consolidate around exclusively.
Choose so like us. So there are a lot of internal kinds of design changes that are becoming more of the main screen, so it will take time.
But I think we're going to over time.
Have some of that standardization.
Thank you. Michael.
Any other concluding cream, remarks.
I don't see any hands.
So I think we I think we conclude this meeting now.
The recordings will be posted, and I mean talk to you in half a year from now. But hopefully there will be some exchange over the mailing list in between.
Thank everybody, and have a have a great evening or great a great rest of the day.
Bye, bye!
Thanks.
Thanks. Alexander.
Thanks, bye!
Well done!
Bye, bye!
Bye!
Hi!
Thank you. Bye.