Latest revision as of 21:06, 15 September 2023

Update on GEM

Xinzhan's slides on GEM efficiency correction: [1]
suggestions: for gain matching, GEM3 both x and y can use some matching (scale up the blue so the lower end align with the red)

Ye's slides: slides.
- The focus is to find consistency in the "horizontal scaling" of the Shower spectra and the observed MIP height and baseline shift vs. current. We compared ("MIP height" + "baseline *2") * "T_window" and "MIP integral" and found they agree with each other within error bars. Here "T_window" is the peak integral divided by height from the decoder, which for a triangular shaped pulse would represent full pulse width (end - start) divided by 2. This is why we need to multiply baseline shift by 2 * T_window because the baseline shift would affect the integral like a rectangle (not triangle).
- In extracting T_window, found two values. This is due to slight peak mis-identification due to pileups.
- Preshower does not show the same PMT gain shift, though its background is quite high.
- A difference observed between Shower and Preshower is that Shower background is dominated by small pulses, while Preshower is dominated by MIP pulses.
suggestions:
- for MIP scaling factor, focus on using runs after the "mysterious" 20% shift; uncertainty in the scaling factor should only be from MIP fit and other similar factors, not the 20% shift of unknown origin.

Mike worked on getting event/trigger statistics
Carter continued fitting the timing resolution. Suspect position contribution is to all of T, B, C, and D. Note: C and D are both read out from beam-right only.
Xiaochao setup overleaf for writing, see link

@@ Line 4: / Line 4: @@
 =Update on rate study=
-*Ye's slides: [https://solid.jlab.org/wiki/images/a/a8/08312023_beamtest_update.pdf slides]
+*Ye's slides: [https://solid.jlab.org/wiki/images/a/a8/08312023_beamtest_update.pdf slides].
+**The focus is to find consistency in the "horizontal scaling" of the Shower spectra and the observed MIP height and baseline shift vs. current. We compared ("MIP height" + "baseline *2") * "T_window" and "MIP integral" and found they agree with each other within error bars. Here "T_window" is the peak integral divided by height from the decoder, which for a triangular shaped pulse would represent full pulse width (end - start) divided by 2. This is why we need to multiply baseline shift by 2 * T_window because the baseline shift would affect the integral like a rectangle (not triangle).
+**In extracting T_window, found two values. This is due to slight peak mis-identification due to pileups.
+**Preshower does not show the same PMT gain shift, though its background is quite high.
+**A difference observed between Shower and Preshower is that Shower background is dominated by small pulses, while Preshower is dominated by MIP pulses.
 *suggestions:
 **for MIP scaling factor, focus on using runs after the "mysterious" 20% shift; uncertainty in the scaling factor should only be from MIP fit and other similar factors, not the 20% shift of unknown origin.