ECCE Detector Location Meeting Oct 8, 2021 (1:08 PM) Cameron Dean: To add to the barrel discussion, Sourav has a detector simulation to switch out the Barrel AC-LGAD. We're working on the pull request now and can run this as a small subsample to quantify different detector technologies, independent of the alrge campaign (1:11 PM) Kenneth Read: https://docs.google.com/spreadsheets/d/181rBQbkuRVywHYZ7rmjvZwm_Chg7W53N34blqgnsn-w/edit#gid=680498336 (1:22 PM) John Lajoie: Agree with Greg - we need to have some management/control after we make decisions here today. (1:24 PM) Bock, Friederike: how about we switch back to the number from G$ (1:24 PM) Bock, Friederike: G4 (1:50 PM) John Lajoie: The inner radius of the hpDIRC frame cannot change w/o changing the electron acceptance. Nor can we change the inner radius of the BECAL (or outer radius of the hpDIRC frame) without affecting the electron acceptance. That has to stay fixed for now. So what can you do? All you can do is play with ordering. Put the hPDIRC at the maximum radius you can ideally at the outer radius of the hpDIRC frame. Inside that comes the mRPC and uRWell (1:51 PM) John Lajoie: In the end this plays with the mRPC and uRWell locations at the level of a few cm, and this cannot cause the performance to drop off a clifff. (1:53 PM) Douglas Higinbotham: If the TOF fits in the DIRC frame; then I think mechanical model is good enough or is a small shift needed? (1:54 PM) John Lajoie: mRPC + uRWell needs 8cm + 2 cm = 10cm, this is what I have been hearing. (1:55 PM) Tanja Horn: @Doug for this the issue is where the bars are located in the frame - as Joe pointed out it's a complex problem (1:58 PM) Douglas Higinbotham: 👍🏼 (1:58 PM) Greg Kalicy (CUA): I agree with John 100% (2:00 PM) Douglas Higinbotham: Evenb more pragmatic, we need to be able to show it all fits for the review and we can still say further optimization is being explored. (2:00 PM) Douglas Higinbotham: *Even (2:00 PM) Tanja Horn: Yes, indeed. I need to know how to update/revise the mechanical model (2:01 PM) Tanja Horn: to make the image(s) for the proposal (2:01 PM) John Lajoie: 100% agree Doug - so we select what is safe now, and note that we can continue to optimize. (2:01 PM) John Lajoie: Including the last point improved the tracking resolution by 20%. SO move it 2-4% closer and how much worse do you think it will be? (2:03 PM) John Lajoie: I agree with Or that tracking resolution is something we will be hit on no matter what. I would rather be hit on just that, and not BOTH tracking and barrel electromagnetic calorimetry (2:06 PM) Douglas Higinbotham: I would be surprised if a thin 2cm uRWell would mater; so if we want to push tracking then from outer too inner uRwell, DIRC, MRPC. (2:08 PM) John Lajoie: That's a very valid concern, Or - the mRPC material in front of the hpDIRC. (2:08 PM) John Lajoie: That would need simulations to quantify. (2:11 PM) John Lajoie: So here's another potential path: We have 2cm in the frame already for the uRWell between the hpDIRC and the BECAL. So we put it there. The hpDIRC stays as it is. This then all boils down to ONE question that can be answered by simulations - can we tolerate the mRPC in front of the hpDIRC. We do the simulations and return to the discussion with data in hand. (2:18 PM) Joe Schwiening (GSI): If we move the uRWell inside the DIRC radius, then we lose the benefit from the extra track point outside the DIRC on the hpDIRC performance. (2:19 PM) John Lajoie: Good point, OK. (2:20 PM) Joe Schwiening (GSI): 👍 (2:25 PM) Bock, Friederike: EEMC stops at 61 cn (2:25 PM) Bock, Friederike: cm (2:25 PM) John Lajoie: OK - so the 5cm that Jin referred to is real (2:25 PM) Bock, Friederike: yes (2:25 PM) Tanja Horn: What is between endcap EEMCal and DIRC frame (2:26 PM) Bock, Friederike: cabelling for the inner detectors and 1cm steel for holding the EEMC (2:26 PM) Or Hen: have to jump to a DNP meeting. sorry. (2:26 PM) Cameron Dean: Tracking support barrel with a lead support (2:26 PM) Kenneth Read: Thank Or (2:26 PM) Tanja Horn: which one? (2:26 PM) Cameron Dean: Steel yes (2:26 PM) Kenneth Read: Thanks Or (2:27 PM) Tanja Horn: tracking support or cabling or both? (2:27 PM) Cameron Dean: Both, cabling and carbon fibre frame in the simulation (2:27 PM) Cameron Dean: I was using tracking support as a catch all (2:30 PM) John Lajoie: uRwell - hpDIRC - mRPC from inner to outer (2:31 PM) Cameron Dean: Current simulation is: uRwell - hpDIRC - TOF (2:31 PM) Joe Schwiening (GSI): The DIRC would prefer the uRwell outside the DIRC to mitigate multiple scattering inside the DIRC bars (2:31 PM) Greg Kalicy (CUA): uRwell outside the DIRC had advsntage! (2:31 PM) Greg Kalicy (CUA): thanks Joe (2:33 PM) Douglas Higinbotham: So it sounds like we have converaged on uRWell, DIRC and mRPC (inner to outer). Though we want a quick check of that uRWell location. (2:34 PM) Douglas Higinbotham: Sorry, outside DIRC.... (2:34 PM) Joe Schwiening (GSI): +1 for uRWell outside DIRC (2:37 PM) Bock, Friederike: I have to leave unfortunately (2:38 PM) John Lajoie: So I see several key questions; (1) What is the optimal radius for the hpDIRC within the DIRC frame? (2) If we remove the large R uRWell and replace it with a double uRWell at 67cm what is the track momentum resolution? (2:39 PM) John Lajoie: WIth these answers we can move forward on solid ground. (2:44 PM) cfanelli: @john: we can check that... (2:44 PM) John Lajoie: Thanks Cristiano! (2:44 PM) Douglas Higinbotham: I also like quickly checking if this solution works. (2:45 PM) Joe Schwiening (GSI): Agaiin: the DIRC folks would like to have the track point outside the DIRC (2:45 PM) John Lajoie: Why Joe? (2:48 PM) Douglas Higinbotham: So we would like uRWell's on both sides of the hp-DIRC. (2:48 PM) Joe Schwiening (GSI): I do not think that the DIRC currently is at the inner-most possible radius at all (2:49 PM) Douglas Higinbotham: The tracking into the DIRC and tracking out. (2:49 PM) Douglas Higinbotham: And we just need 2cm. (2:52 PM) Joe Schwiening (GSI): Yup, we only look at small radial variations within the frame (2:54 PM) John Lajoie: I am good. (2:54 PM) John Lajoie: Thanks everyone! (2:55 PM) Douglas Higinbotham: So, we are going to study the following order: hp-DIRC, uRWell, and mRPC. We do need to move the hp-DIRC in 2cm. checked by Joe/Greg and Christiano will check tracking performance. (2:56 PM) Douglas Higinbotham: And yes, it needs to fit in the mechanical model. (2:56 PM) Murad Sarsour: On another subject: is the position for mRICH final in e-arm?