Status of Muon chambers and UF/PNPI HV-system.

23.02.09Oleg Maev 1

Status of Muon chambers and UF/PNPI HV-system.

Outline

- Status of Muon chambers

- HV-system, status, tests and repairing of voltage sensors (VS), recalibration VS in situ, spare channels.

23.02.09Oleg Maev 2

Status of Muon chambers

M2-M5 stations

1104 Chambers are at 2,5 kV

from spring 2008

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Status of Muon chambers

Q1:

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Status of Muon chambers

Q2:

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Status of Muon chambers

Q3:

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Status of Muon chambers

Q4:

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Status of Muon chambers

• In total from 4416 gaps 99,7 % are OK

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Status of Muon chambers

Last spare R4 chambers were delivered from PNPI at the end of 2008.

So we have spare:

M2R4-11 chambers

M3R4-15 chambers

M4R4-15 chambers

They passed gas leak, capacitance and integrity tests successfully and they are awaiting some components to perform final assembling and final tests.

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UF/PNPI HV-system

8 Master modules and 56 RDB#36 modules (960 from 1104 chambers)

Status on the end of October 2008.1. Masters work without problems after summer repair.

2. Several RDB channels had a permanent pre-trip status (I > Imax, but ttrip< 1s).

Tests of voltage sensors of RDB channels in “transparent mode”:

(HV on premier PS =2,5 kV, Vset>=2,6kV) 13&20.10.08 have shown many bad channels:

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UF/PNPI HV-system

Test 28.11.08 HV on premier PS =2,5 kV, Vset=2,7kV

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UF/PNPI HV-system

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UF/PNPI HV-system

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UF/PNPI HV-system

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UF/PNPI HV-system. Spare elements.

Master modules:mother board – 1

with 8 channels (repaired by Nikolay last month)

plus 8 spare channels which aren’t checked yet

RDB#36 modules:mother boards – 4

channels – 36 x 3 + 3 =111 chs

to be repaired – 45 chs

Reserve inside system: Master chs. – 8,

RDB chs. 12x8=96

Quality of them is ?

This year our understanding of system really grown up. And now, we ensure that the HV-system is working properly in acceptable and safe mode.

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Conclusion.1. After about half of year of system in operation we found 2,5%

unstable voltage sensors in RDB modules and approximately the same percentage of noisy (trips of channels) channels.

The reasons of bad channels are various. There is a simple mortality of electronic components and also an inconsistency of component parameters to the design requirements. Part of them have been found and partially fixed by Nikolay.

2. We are sure that the HV-system doesn’t need any global upgrades (replacing of HV-resistors etc.) or principal changes at present! We must provide just a final tuning of system and the permanent monitoring of it during operation.

3. SW for recalibration of voltage sensors in situ under preparation and Evgeny hopes to finish it before end of March. Next task is installation and debugging this SW in the PIT.

UF/PNPI HV-system