02 pedestal(capID)


 Run 9067013, 30K st_physics events, spectra accumulated separately for every cap.

Top plot pedestal (channel), bottom plot integral of pedestal peak to total spectrum.


Fig 1. CAP=122

Fig 2. CAP=123

Fig 3. CAP=124

Fig 4. CAP=125

Fig 5. CAP=126

Fig 6. CAP=127

Fig 7. Raw spectra for capID=125. Left: typical good pedestal, middle: very wide pedestal, right: stuck lower bit.

For run 9067013 I found: 7 tiles with ADC=0, ~47 tiles with wide ped, ~80 tiles with stuck lower bit.

Total ~130 bad BPRS tiles based on pedestal shape, TABLE w/ bad BPRS tiles

Fig 8. QA of pedestals, R9067013, capID=125. Below is 5 plots A,...,F all have BPRS soft ID on the X-axis.

A: raw spectra (scatter plot) +  pedestal from the fit as black cross (with error).

B: my status table based on pedestal spectrum. 0=good, non-zero =sth bad.

C: chi2/DOF from fitting pedestal, values above 10. were flagged as bad

D: sigma of pedestal fit, values aove 2.7 were flagged as bad

E: integral of the found pedestal peak to the total # of entries. On average there was ~230 entries per channel.

Fig 9. BPRS pedestals for 'normal' caps=113,114,115 shown with different colors

Fig 10. BPRS pedestals for caps=100..127 and all softID , white means bad spectrum, typical stats of ~200 events per softID per cap

Fig 11. BPRS:" # of bad caps , only capID=100...127 were examined.

Fig 12. BPRS:" sig(ped)

Fig 13. BPRS:" examples of ped distribution for selected channels. Assuming for sing;e capID sig(ped)=1.5, the degradation of pedestal resolution if capID is not accounted for would be: sqrt(1.5^2 +0.5^2)=1.6 - perhaps it is not worth the effort on average. There still can be outliers.