No dead cells (yet) The integrated luminosity since the last meeting: 477 pb -1 ; since the last TS: 609 pb -1 ; smooth operation since the last meeting, with several LED based gain corrections: 16-Oct, 21-Oct, 01-Nov, 09-Nov, 18-Nov. HCAL status Yu. Guz

HCAL HV corrections – LED view LED-based HV corrections sum/sum ref, 56 central cells 60 pb -1 TS3, source calibration 87 pb pb -1 Since the last TS, 6 LED-based corrections: 04-Oct, 16-Oct, 21-Oct, 01-Nov, 09-Nov, 18-Nov Yu. Guz 101 pb -1 TS3 reference: :05: pb -1 before TS3, a “plastic ageing” correction was used, which appeared to be somewhat overcompensating. Now the correction map was updated on the basis of the 137 Cs scans at TS2 and TS pb -1

HCAL HV corrections in Yu. Guz total of Cs calibrations and 16 LED-based corrections performed. 2-3 more LED based corrections before the end of 2012 a 137 Cs scan will be performed at the end of the 2012 run attempts of compensation for the “plastic ageing” are visible. LED-based HV corrections sum/sum ref, 56 central cells shutdown 137 Cs calibration TS1, 137 Cs calibrationTS2, 137 Cs calibration TS3, 137 Cs calibration

HCAL HV corrections in II Yu. Guz LED-based HV corrections sum/sum ref, 56 central cells TS1 TS2 TS3 an alternative view, as a function of delivered luminosity

Yu. Guz HCAL HV corrections in 2012 – L0Hadron view ECAL update TS1TS2TS3 TCK changes ? ~ 07-Nov

Yu. Guz HCAL LED / PIN stability A systematic drift of PIN amplitudes is visible in HCAL: on average, -1.4% since April, -0.4% since TS3. As it is not clear whether it is because of reduction of the LED light or ageing of PINs themselves, the corresponding correction is not applied to PMTs (anyway, the effect is small between two TSs). Such effect is not observed in ECAL, probably because the ECAL LEDs and PINs are installed out of the detector aperture.

Yu. Guz HCAL LED / PIN stability The PINs are not taken into account, because: the effect between two TS (source calibrations) is small (~ %) it is not clear whether it is because of reduction of the LED light or ageing of PINs themselves. The comparison of the Outer PMT trends with and without PIN corrections gives some preference to the hypothesis that the reduction is due to PINs themselves and not LED light (next slide). there are several PINs which have instabilities at this level due to contacts at the FEB inputs (next-to-next slide)

Yu. Guz HCAL LED / PIN stability In case of not correcting to PINs, the trend looks more stable. This supports the hypothesis that this is the degradation of PIN response and not LED light. There is an overall shift by -0.65% in the period after the TS3. It is due to the source calibration, this was mentioned in the previous HCAL report, 10-Oct, slide 8. NOT corrected for PINs corrected for PINs

Yu. Guz HCAL LED / PIN stability PINs with irregular fluctuations, presumably due to problems in FEB input contacts