ECAL

ECAL

Technical stop: Recovery during July technical stop (detector +

monitoring system) C-W pumping frequency measurements

Comparison of LEDs with minbias data

ECAL cells DQ

Irina Machikhiliyan, 20.07.2011

Fills 1799 – 1955Average relative PmToPin change with respect to 1st run (fill 1799)


1799,21/5/11

Time, minutes.One point per run

Red: physics runsBlack: the rest

1901,28/6/11

1944,14/7/11

1955,18/7/11

Fills 1799 – 1955, InnerAverage relative PmToPin change with respect to 1st run (fill 1799)



1955,18/7/11

1944,14/7/11

1901,28/6/11

1799,21/5/11

Fills 1799 – 1955, MiddleAverage relative PmToPin change with respect to 1st run (fill 1799)



1955,18/7/11

1944,14/7/11

1901,28/6/11

1799,21/5/11

Fills 1799 – 1955, OuterAverage relative PmToPin change with respect to 1st run (fill 1799)



1955,18/7/11

1944,14/7/11

1901,28/6/11

1799,21/5/11

Run #95947 (fill 1944) wrt run #94385(last physics run of the latest fill 1901)

PmToPin(95947) /PmToPin(94385)


R/O crate 20, Not present in #94860 (6 Jul), present in # 95656 (12 Jul)

PmToPin(94860) /PmToPin(94385) = 1.023PmToPin(95656) /PmToPin(94385) = 1.009

PmToPin(94860) /PmToPin(94385)

Up to 12% recovery in the Innermost / “horn” areas.

Average ratio per section:Inner: 1.045 (r.m.s. 0.019)Middle: 1.029 (r.m.s. 0.019)Outer: 1.018 (r.m.s. 0.022)

Average frequency <f>, kHz: Group # 10 May 5 Jul

#1 64.8 61.9 #2 65.5 65.2 #3 68.9 69.1 #4 69.0 69.2Innermost C-Ws (group #1) show decrease of <f>

on ~4%, which must not affect C-W performance. <f>-values for other C-W groups are stable.

C-W pumping frequency(done together with Yu. Guz)

- initial measurement: 10 May, logbook entry: http://lblogbook.cern.ch/CALO/1587- second measurement: 05 Jul, logbook entry: http://lblogbook.cern.ch/CALO/1701

1

2

3

4


http://lblogbook.cern.ch/CALO/1587



LEDs vs mbias: fills 1799 – 1883Average relative PmToPin change with respect to 1st run (fill 1799)


Fill 1799: 21 May, 10.5 hoursFill 1883: 21 Jun, 18 hours

Physics data: mbias selectionSignal: position of π⁰ peakPhotons: et > 300 MeV

M(92035) M(94012) M(94012) / M(92035)

PmPin(94012)/PmPin(92035)

M(1799) M(1883) M(1883) / M(1799)

All 135.1±0.8 130.2±0.7 0.964±0.006 0.952 134.1±0.2 σ = 8.6±0.1%

131.0±0.1σ = 9.1±0.1%

0.977±0.001

Inn 131.6±1.9 125.6±1.2 0.954±0.016 0.936 132.0±0.3σ = 8.7±0.2%

127.4±0.3σ = 9.1±0.2%

0.965±0.003

Mid 135.7±1.3 132.8±1.3 0.979±0.013 0.957 135.1±0.3σ = 8.5±0.2%

132.9±0.3σ = 9.3±0.2%

0.984±0.003

Out 134.7±1.3 130.9±1.3 0.972±0.013 0.956 134.8±0.3σ = 8.5±0.2%

131.6±0.2σ = 8.6±0.2%

0.976±0.003

Run 92035

Run 94012

LEDs vs mbias: fill1883, signal change during the fill (1)


(PmPin(N) – PmPin(0)) / PmPin(0) (PmPin(N) – PmPin(0)) / PmPin(0)

N (Relative run #) N (Relative run #)

All cells

(M(N) – M(0)) / M(0) (M(N) – M(0)) / M(0)

Inner cells

Net π⁰ peak π⁰ peak, Inner


LEDs vs mbias: fill1883, signal change during the fill (2) (PmPin(N) – PmPin(0)) / PmPin(0) (PmPin(N) – PmPin(0)) / PmPin(0)

N (Relative run #) N (Relative run #)(M(N) – M(0)) / M(0) (M(N) – M(0)) / M(0)

Outer cells

π⁰ peak, Outerπ⁰ peak, Middle

Middle cells

For π⁰-signal:try to add other selections? (π⁰ position compatibility for different selections should be checked)

Detection of problematic cells, fills 1799-1901 (1) for each [physics] run #N and for each

LED ratio R(N,LED) = <PMtoPIN(N, LED) / PMtoPIN(0, LED)> is produced. 1/ R(N,LED) serves as correction factor to crudely account for :

(1) clear fibers rad. damage(2) signal change due to PM training(3) ? some other factors ?

(2) After correction is done, cell is marked as suspicious if:- maximal deviation of corrected PMtoPIN(N) from the PMtoPIN(0) over all runs is ≥ 10%- or signal change over two adjacent runs ≥ 5%

- or maximal width of LED peak over all runs > threshold

(3) Individual check of suspicious cells (see next slide)

Finally : 19 cells have been found

Average relative PmToPin change with respect to 1st run, corrected

Correction factor for the last run of fill 1901

Time, minutes


Example of the cell with “unexpected” behaviour (O 61/28)Original trend

Correction factor for current cell

Corrected trend

Correction makes things worse

6%3.5%

Cells where correction makes things worse


List of problems + suggestions(1)One cell out of 19 must be excluded for all runs (O 51/56, bad C-W:

unstable, noisy spectrum, presently: very low gain)(2)The rest: noticeable signal change in one-few-many runs. In many cases

it is accompanied by an increase of the r.m.s of LED peak due to noisy spectrum. Signal change: could be gradual drift during some time period(2 cells); one abrupt change(1 cell); unstable behaviour (more than one abrupt change, 11 cells)

• Suggestion: – if for certain runs spectra are noisy but signal change is small (1-2%), do nothing

(4 cells)– if few runs are affected and signal change is large, mask the cell for that

particular run(s) or make [rough] gain corrections if possible– if during certain period signal variations are large and frequent: exclude such

cell for this period

Correction factors / periods to mask for each cells could be provided before the beginning of the next week. Do we agree that the reference point should be fill 1799? Run-based or fill based corrections?Irina Machikhiliyan, 20.07.2011

Example #1: Cell O-01-32

The signal change is not significant, no action is needed


Average relative PmToPin change with respect to 1st run

LED peak r.m.s. (ADC counts)



In one run over several hundred signal decreased, r.m.s. OK

Mask this cell for one run?




Make correction for this period


1400 ADC cnt

Transition

1300 ADC cnt




Example #4: Cell O-09-15Average relative PmToPin change with respect to 1st run

Make correction for this period + exclude some runs


1100 ADC cnt

Transition

800 ADC cnt

Ex #5:Cell I-40-29

Large signal variation, exclude period t<22000, correct the rest w.r.t. first point

Ex #6:Cell O-09-17

Large signal variation, exclude period 20000 - 30000

Average relative PmToPin change with respect to 1st run Average relative PmToPin change with respect to 1st run

LED peak r.m.s. (ADC counts) LED peak r.m.s. (ADC counts)

Ex #7: Cell O-08-57

Gradual signal increase for t < 5000. Correct all points > 5000 ?

Ex #8: Cell I-41-43

Signal increase, than gradual decrease for t < 5000. Correct points < 5000 ?

Average relative PmToPin change with respect to 1st run Average relative PmToPin change with respect to 1st run

LED peak r.m.s. (ADC counts) LED peak r.m.s. (ADC counts)

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