Make New Entry, Make Followup Entry
User name jroche
Log entry time 21:09:35 on October 9,2010
Entry number 334120
Followups:
- 334122 10/09/10 21:14 Jin Huang HV change on Gas Cer
- 334323 10/10/10 23:17 jroche Cerenkov PMT1 now showing a nice pe peak
Just changed the pedestals and amplitude calibration of the Cerenkov in the data base. The lines below show the changes. This should solve the issue with Cerenkov 6 noted by Salvatore and others earlier today.
I call this a partial calibration because the data so far show no PE peak for Cerenkov 1 (see plot) I asked the shift crew to increase the HV for this cerenkov by 25 V. I will follow up with the data.
More details
- For the calibration, I used run 7048 (Thursday night) and 7088 thei afternoon. Results are consistent.
- The plot below shows cerenkov ADC without pedestal subtraction for run 7088. The red line show the pedestals while the green lines show the PE peak.
- The pedestals of cerenkov 2, 8 and 9 are twice as large as the other ones. Looks like noise to me.
pedestal width: 4, 3, 10, 4, 3, 4, 3, 4, 8, 7
- Change in the database
Pedestal values of Gas Cherenkov channels --------------------------------------
old values: 387 321 316 289 443 501 605 436 349 358
new values: 389 316 315 290 441 499 467 435 348 357
Amplitude transformation coefficients of Gas Cherenkov channels
----------------
old values: 1.353 1.338 1.285 1.261 1.263 1.285 1.252 1.304 1.200 1.269
new values: 0.992 0.976 0.936 0.968 1.246 1.288 1.304 1.108 0.944 1.018
###############
FIGURE 1
