Discussion
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Discussion 20mSpeakers: Anastasiya Magazinik (Tampere University of Technology (FI)), Connor Miraval, Filippo Resnati (CERN), Jamie Boyd (CERN), Jean-Pierre Corso (CERN), Johan Bremer (CERN), Larry Bartoszek (University of Colorado Boulder (US)), Milind Vaman Diwan (Brookhaven National Laboratory (US)), Steve Trabocchi (Brookhaven National Laboratory), Steven Linden, Yichen Li
Some discussion and homework
Putting this entire list here. Additional comments from this meeing will be made below.
4 items were discussed.
1) A report for the PBC is being prepared by Jamie and Anastasya. The draft report is almost ready. Jamie will share it when it can be commented on. Steven, Yichen, and Connor will look though the report for details regarding FLARE. Both vertical and horizonal insertion are options in this report.
2) Larry provided a summary of the horizontal insertion idea.
Johan: at CERN the seals have not been successful for large surfaces. In the end all experience was with welding including for large successful cryostats. Same issue has surfaced for ATLAS cryostat and the decision is to weld it.
For the foam cryostat, some more thining is needed. What is the essential difference between FLARE cryostat and the protodune style.
The outside walls of the cryostat must be able to withstand some purging of the gas. Inner vessel takes all the forces, and the outer one just takes a small bit of pressure. Few millibar of pressure is enough.
The cold vessel must have no leak of argon for CERN safety purposes . The cold vessel is not a vacuum vessel, but some means of leak testing can be found (Johan).
Structurally the jetsealed lid is probably ok. But after making it cold the structure will deform and will make it difficult to be replaced making the idea of a future upgrade difficult.
3) Yichen presented his calculation of the heat leak for FLARE and a conceptual design for gas based purification.
Turbo-Bayton to Gran Sasso is delayed by 14 months. So this needs to be considered.
The use of direct LN2 cooling from surface will be needed whenever there is a power cut. The storage volume of LN2 will be needed. For ATLAS, the rule is to be able to operate for several hours without power, and then switch to surface LN2 if needed.
For ATLAS there are no backups for compressors, etc.
4) Anastasiya: LAR storage tank as designed does not fit through the shaft, and so we need some options.
The tank was sized for 30000 liter storage. The specification was from Steven Trabocchi. The spec was for 57000 lt. This may be too conservative because he anticipated losses.
Yichen, Connor, Anastasiya will look through the tank options and make decision on a smaller tank.
The dewer could be brought down before the staircase is installed.
The LAR tank has to be kept cold with a heat exchanger inside the LAR volume. The reason for this is to make sure we can take the detector LAR out without large losses. This will also allow us to keep the tank volume relatively modest for FLARE.
Update Jun 14: Yichen will decide on this tank and modify the PID
================ist of homework
Connor will make sure all drawings from Larry and Steven Trabocchi have been converyed to Anastasiya
0) Get information from Jetseals - Larry
Connor will contact Larry and Jetseals to understand what is needed to make further progress.
"I believe we can make a seal to fit a cavity close to what is drawn up. I do have a concern with the leak rate. Everything leaks, the challenge is getting it small enough that it is manageable. There is a lot of seal line for a small flaw to create a leak just large enough to create an issue. We will have to check for to see if we can find a tin plating tank large enough. "
Steve Hudlet, PE, Engineering, JETSEAL, Inc.
Updage June 14: Larry will ask about a cost estimate to do this prototype Does it have to be cold ?
1) Conceptual design and options for electronics -- Steven is arraning a meeting with Sergio, Aleksey and others.
Prafull Purohit is spending some time understanding QPIX design. The power cost of QPIX is very low ~ few microwatts.
A document has been written to summarize where we are.
A design for the anode is needed with some tentative calculations of the heat load and performance.
2) Cabling options to get cables across to the feedthroughs. -- Everyone ?
The one unique aspect to FLARE TPC design is that the cables have to cross over TPC modules. This means the grounding planes have to be considered
to make sure there is no field in the place where cables must go.
We could consider all optical readout, but we must then also consider optical power. Power and readout must be done over fiber.
A new paper from DUNE is circulating about this development. We should use it.
"Characterization and Novel Application of Power Over Fiber for Electronics in a Harsh Environment".The draft appears as DUNE-doc-30532 (link). (also on arxiv: https://arxiv.org/abs/2405.16816 (added by Jamie))Who is going to do this ?
3) Concepts for light readout. -- Jianming ? Trigger ? Time tagging for LHC bunch.
New SIPMs are VUV sensitive down to 120 nm with 10% efficiency
BNL has ordered 18 units at $250 each. We need to get these tested in Yichen's LAR chamber.
4) Electrical field calculations in the gap -- Yichen using comsol.
Comsol -- can it use stp files ? This module apparently costs $8000 per year.
Check with MIcki Chiu: Module is needed.
5) electrical field calculation in special positions near the cathode -- Yichen using comsol
Yichen will communicate with Jamie Boyd about using Comsol at CERN. And what is needed in terms of getting access as well as putting in the
correct design data.
6) Some simulations studies to understand the fiducial losses due to gaps. -- Matteo/ Wenjie
Pixel simulation ? -- full simulation is not ready yet, but an effective simulation could be done with just different binning.
--- Put some deadlines and get the simulation note finished.
--- Get comments on simulation note by May 15.
We need to work on reading this simulation paper.
6') Include the Baby-MIND detector modules in simulation. Matteo
Update June 14: Larry needs to provide some geometrical details.
7) Settle on a very small prototype / using BNL 260 liter system ?
--- Keep it < 10 cm drift. 16 channels of pixels, and 8 channels of SiPMs.
--- Readout out of the liquid.
--- Aleksey ?
Aleksey, Connor and Yichen will work together to make a drawing or idea for a small prototype
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For the CERN FPF civil construction and ingtegration document we can list the following people as technical contributors to the document from FLARE.
Steven Linden, Connor Miraval, Larry Bartoszek, Steve Trabocchi, Yichen Li
Please send comments on the document to MVD
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Common scientific narrative for FLARE simulation and Technical notes are needed.
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