SoLID Ecal Weekly 20230818

Rate discussion

• Mike's slides on MIP shift (integral): 08_17
• Ye's slides [1] on MIP and baseline shift (height), and expected rate of low-energy background in ECal from beam-on-target simulation
• suggest for the MIP shift study:
  • Ye can apply beam current cut to get baseline (from "before pulse" window) for intermediate beam current values;
  • decompose MIP shift as sum of baseline shift and PMT gain shift. To do so, we need a few plots clearly indicating each component:

1. plot total MIP peak integral vs beam current (Mike already has this)
2. use 2D peak integral vs. peak height plot, extract a "time factor", let's call it t_trig
3. plot baseline vs beam current (Ye already has this but need more current values), expect an exp() function
4. multiply baseline with "t_trig" then times two (2), plot this vs. beam current; expect an exp() function
5. plot MIP height (minus baseline) vs. beam current
6. multiply MIP height (minus baseline) from above with t_trig, plot this vs. beam current
7. add 4 and 6 from above, do they agree with 1?
8. check how much horizontal scaling is needed for the Shower histogram to match the 5 uA run (from Ye)
9. does the scaling from 8 resembles the inverse of the values from 3 above? (make a comparison or plot)
10. If possible, plot all above vs. background rate instead of beam current (but only if we have a reliable way to get the rate).

• suggest for rate comparison with beam-on-target simulation:

1. Can we add a tiny Edep cut, rather than greater than zero?
2. Can we possibly get this from random trigger FADC raw signals?

SPD timing

• Carter's slides
• need to add C-D data, perhaps check the timing propagation