Pion Meeting January 15 2021 11AM ET

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Agenda

1. Lucite detector shielding from downstream and at inner radius (Elham) [1]

Attendance

David, Elham, Wouter

Minutes

• New geometry increased rate of pions to electrons from 0.1 to 100, and would increase rate of photons similarly, but the effect on photons was not observed due to backgrounds from downstream
• New shielding (1cm lead) was added on the downstream and inner radial faces to remove the low energy electron backgrounds: visibly removes background for Moller generator, while keeping pion generator signal
  • Rate of backwards moving impacts on lucite is reduced for Moller generator: 1e6 to few 1e4
  • Rate (GHz/uA/det) change adding shielding: 2.9e-5 to 9.4e-6 for Moller electrons, 2.2e-2 to 1.2e-2 for photoelectrons from Moller electrons, 2.5e-5 for pions (constant), 5.4e-4 for photoelectrons from pions (constant)
  • Location of impact on lucite plots show reduction in impact from inside and from back reduced, now dominated by impact at top
  • Remaining impacts at top dominated by events generated in showermax (in sector and neighboring sector)
  • Q: How much of the rate is really coming from the top edge? Separate total rate into parts. Also separate by origin: front showermax detectors, back showermax detectors
  • Q: Separate rate tables for open and closed sectors (e.g. slide 19), and look at background origins separately too
  • For asymmetry, background is an issue, but for rate measurements we may be fine since gems will
  • Q: Multiplicity of shared particles per event: is large rate due to large multiplicity of low energy events?
  • Q: Can we weigth plots with photo-electrons?
• Q: Are there other processes that generate light but don't show up as hits in the lucite detector?
• Absorption of photons at inner radial face? Add absorber and study how this affects rates.
• Possible redesign to put stack of lucite in 90 degree rotated orientation to be less sensitive to diffuse backgrounds?