Transcript HCAL commissioning

HCAL status and plans
Yu. Guz
IHEP, Protvino
Yu. Guz 16/04/2008
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HCAL status: PM/CW & LED-PIN cards
two access periods: 25.02-03.03 (side A), 12.03-18.03 (side C)
● all the LED-PIN cards (both #1 and #2 in all HCAL modules) tuned
uniformly: ~7000 ph.el. at max control voltage)
● several minor repairs during access:
✔ one of HV boards was producing HV 15% higher than others, at same DAC
code  fixed by Anatoly
✔ good news: no CW went dead since Dec’07 during commissioning
✔ PM/CW replacements during access:
continuous current : 1
broken nut : 1
slow discharge after HV OFF (resistor missing) : 1
✔ several cases of contact problems in connectors attached to PM/CW
! four more found later by reflection tests (A.Arefiev) – will be repaired at
the next access (e.g. dosimeter installation)
● ATI connectors: ~20 were repaired (many thanks to Irina!); some more
appeared since then, to be fixed
Yu. Guz 16/04/2008
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HCAL status: HV, noise, spurious trigger rate
HCAL PMs behave stable (no current, no dead CW) at both “cosmic”
(gain=200k) and “almost” physics (Et_max=15 GeV) settings
★ the rate of spurious HCAL triggers at physics settings (Et_max=15 GeV,
Et_thresh=5GeV) was measured yesterday, 15/04/08, by Patrick. It turned
out to be well below 1 Hz :
7.2 GeV
0.05 Hz
5 GeV
0.08 Hz
2.8 GeV
0.15 Hz
1.4 GeV
0.6 Hz
(The preliminary rough estimate performed with integrator readout gave
just an upper limit of ~10 Hz)
 THE HCAL PM NOISE DOES NOT MAKE A PROBLEM FOR PHYSICS DATA
TAKING (however more studies, with data taking, are necessary).
Yu. Guz 16/04/2008
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