Commissioning of the ECAL A-side Irina Machikhiliyan, Reference data samples: #45498 PM HV nominal, LED LV = nominal, 5K of 5 TAE events, LED trigger rate 56 Hz, C-side is also included (taken ) #45396 PM HV nominal, LED LV nominal, ~34K of events, LED trigger rate 2 Hz, 5 TAE events, A-side only (almost 5 hours stability run, taken ) On behalf of joint ITEP / IHEP team: A. Arefiev, N. Filimonov, T. Kvaratskheliya, I. Machikhiliyan, P. Shatalov, T. Zakoryuchkina, A. Zhokhov, S. Zvyagintsev

Irina Machikhiliyan, Test program: -Check of the functionality of PMs / LEDs: several cables were not plugged, fixed; few PM/LED power distribution cables are repaired; -Connectivity test (swapped cables): some swapped control / signal cabling in the Inner section, both PM and FEB sides, fixed; -Pulser test to check connectors quality: 9 connectors on signal cables on PM side, repaired or replaced; -Update / check of connectivity in Database; -~5 hours stability measurements; -Adjustment of integrators: were adjusted 11 of March, but 12 March it was found that pedestal values for two of them drifted. The experience from both C and A-sides shows that current system is not very stable and its adjustment is painful and time-consuming. The general feeling of the group is that it will be worth to modify the circuitry to achieve better performance. Pavel kindly agreed to take care of it. For a moment we have a prototype ready – to be checked on detector. Remaining problems / tasks:  Cells O 58/28(21/08/18) and O 35/46 (19/12/03) – problem on FEB side;  Couple of cells showed instability: to be watched further to understand the reason;  One RJ-45 cable with connector of poor quality (fire signal distribution for LED A310.4), to be repaired (not urgent, LED is now operational) For a moment:  LED intensities are not optimally adjusted. It does not make sense to do it now: they will be tuned after the calibration of PM gains will be done;  PIN system functionality is not yet checked. To be done (data are collected, to be analyzed); Commissioning of the ECAL A-side

Irina Machikhiliyan, r.m.s. of pedestal distribution  “Wide” pedestals: Most of the cells (12) belong to FEB 15 (crate 19)  “Narrow” pedestals: all from FEB 13 (crate 15) ECAL A-side, performance-I (pedestal rms)

Irina Machikhiliyan, ECAL A-side, performance-II (LEDs) Response on LED, nominal settings(1d) (!) 13 cells: amplitude is below 150 counts (!) (among them ~ 6 cells with damaged optical fibers) Response on LED, nominal settings (2d) All three optical bundles, which were replaced – work well!

Irina Machikhiliyan, ECAL A-side, performance-III (stability) Relative signal deviation, first hour excluded (stabilization) 99% of cells are stable within 1% Relative signal deviation, all 4.7 hours of data taking 83% of cells are stable within 1% 95% of cells are stable within 2% several cells with small / absent signal are excluded, few of them were finally repaired

Irina Machikhiliyan, ECAL C-side: ? time-alignment problem ? It seems that some C-side LEDs are even beyond the TAE sequence and therefore they are missing Upd: 23 March: According to Anatoly, there was a problem with LEDTSB recipes after power cut. Should be solved by now. LED response, Prev2LED response, Prev1LED response, T0 LED response, Next1LED response, Next2