Technical Group Meeting
Jamie Boyd, Linden, Yankelevich, Bolotnikov, Bo Yu, Asner, Rescia, Wenjie Wu, Yichen Li, Yu Seon Jeong,
Sebastian Trojnowski.
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Jamie presented studies of radiation in FPF.
Jamie and Jonathan had a positive meeting with CERN management. Collaboration building is quite important. The CDR needs to demonstrate that a capable team is getting formed.
Initial studies on trigger rates in FASER location have started. Rates are somewhat higher than expectation, but studies will progress. The higher rates may come from scattering within the rock with products that end up in the detector.
Trigger rates appears to be sensitive to the settings of collimators in the beam. When collimators are tightened the rates are reduced by factor of 2. The collimator movement is at the beginning at each fill.
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Going through the technical group tasks.
-- Simulations: Jamie commented that some more serious work on the BSM (dark matter physics) simulations are needed. Current work is phenomenology level studies, and we need to make it more firm than that.
--- Some work has been done on dark matter signatures: elastic scattering on electrons, and nuclear scattering.
Dark matter scattering papers:
https://arxiv.org/abs/2107.00666
https://arxiv.org/abs/2101.10338
--- Steven: how detailed do we need the simulations ? Do we need to simulate both options for TPC orientation ?
--- Cryogenics/cryostat: Yichen will give us some of his time. Yichen needs to understand how detailed this needs to be. Needs to work with CERN technical teams. Need engineering support for very preliminary 3D integration design.
--- Steve: How much do the safety requirements inform the design ? How deeply integrated does the safety team need to be at this stage ?
ODH, fire safety need to be robust given that the FPF no longer has a connection to the LHC tunnel.
Jamie: Safety contact at CERN has already been established.
--- Steve: TPC design needs specific BNL expertise on two issues
* TPC modularity needs to take into account the muon rate across the detector face.
* Bo suggests trying to understand the physics requirements..
* Sergio: Modularity could be achieved in many ways. In principle, one can get to whatever spatial resolution one wants if one makes the modules small enough to reduce diffusion.
---- We will organize a special meeting to discussion physics requirements and technical feasibility.
---- Photon sensors/trigger design:
* MVD states that we need to get a rejection of muons by at least 10^3-10^4 to get a reasonable trigger rate.
* First set of homework should be to simply make a table of photo-sensor technologies and their parameters.
--- Wenjie shared some slides of his progress on simulations
* Wenjie has started examining other tau decay modes for event identification