Recap from last week
- Guna reached out to Alexei about neutron cone transition window (Alex was CC'd) --> still waiting to hear back.
- Karim reached out to Gang about updates on impedance calculations.
- Yulia: we need to invite Gang to give an update.
- Yes, but the issue is availability of the computing resources. --> overall issue right now.
Karim on neutral cone/Roman pots interference
- Still not fully quantified how much interference there is --> we can start identifying potential solutions.
- Part of the issue is the HSR/IR finalization - still some work being finished here, which could affect our coverage downstream.
- Guna will update the figure to get some hard numbers on the amount of interference.
Karim on Cabling and RF shielding
- Bend radius of the cables on the RP PCBs? --> question to Jack, Alex already emailed Jack to discuss.
- Different solutions requires different cable lengths and bend radii
- RF shielding -- attach RF fingers to chimney or to the detector?
- Having RF shield on the detector could create additional loss of acceptance --> trap door/brush seals/etc. on the chimney better option to not limit acceptance.
- Default cooling option is the Peltier approach developed by IJCLab --> alternate options to be considered if impedance calculations indicate significantly higher amount of cooling required - TBD from Gang's calculations.
- Issue of RF shielding on bottom edge of detector (toward beam) becomes an issue of acceptance at low-pT --> need to look at how much material will be needed for RF to then perform a simulation to assess impact on particle acceptance. (Alex needs to do this)
- Chang: How often is the detector inserted/retracted in a given year? 100s of times per year.
- This is a problem then for a "trap door" or something which has an additional moving part, another thing which can fail.
- Raphael: For vacuum, do we need to pump on the chimneys themselves? Will there be a pump there?
- Karim & Guna: there has not been a discussion about adding a dedicated pump here, but it's something that needs to be discussed. Is there even space for a pump?
- Raphael: this is why the question is important - we need to really think about how we maintain vacuum in this region to reduce liability to the machine. Would be better to pump the chimneys, if possible.
- Alex: UHV has new "screw pumps" which are quite compact - is there some option which can be space-saving and provide the needed vacuum?
- Chang: What is the vacuum level?
- Yulia to Wlodek: what was the grounding scheme for the STAR Roman pots? Where were the power supplies located? --> Need to discuss, Alex will follow-up.
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