Yu. Guz

• 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

12012-11-21

Yu. Guz

HCAL HV corrections – LED viewLED-based HV correctionssum/sumref, 56 central cells

60 pb-1

TS3,

sou

rce

calib

ratio

n 87 pb-1 129 pb-1

Since the last TS, 6 LED-based corrections: 04-Oct, 16-Oct, 21-Oct, 01-Nov, 09-Nov, 18-Nov

22012-11-21

101 pb-1

TS3 reference: 2012-09-30 10:05:56

107 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 137Cs scans at TS2 and TS3.

103 pb-1

Yu. Guz

HCAL HV corrections in 2012

32012-11-21

• total of 4 137Cs calibrations and 16 LED-based corrections performed. • 2-3 more LED based corrections before the end of 2012• a 137Cs scan will be performed at the end of the 2012 run

attempts of compensation for the “plastic ageing” are visible.

LED-based HV correctionssum/sumref, 56 central cells

shut

dow

n 13

7 Cs

calib

ratio

n

TS1,

137 C

s ca

libra

tion

TS2,

137 C

s ca

libra

tion

TS3,

137 C

s ca

libra

tion

Yu. Guz

HCAL HV corrections in 2012 - II

42012-11-21

LED-based HV correctionssum/sumref, 56 central cells

TS1 TS2 TS3

an alternative view, as a function of delivered luminosity

Yu. Guz 52012-11-21

HCAL HV corrections in 2012 – L0Hadron view

ECAL updateTS1 TS2 TS3

TCK changes

? ~ 07-Nov

Yu. Guz 62012-11-21

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 72012-11-21

HCAL LED / PIN stability

The PINs are not taken into account, because:

• the effect between two TS (source calibrations) is small (~0.3-0.4%)

• 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 82012-11-21

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 92012-11-21

HCAL LED / PIN stability

PINs with irregular fluctuations, presumably due to problems in FEB input contacts