Cavern intervention, for the detailed Summary here see the e-log:
- BOARDS:
- LV board with increasing temperature replaced, temperature now OK.
- LV board for Igap for sectors 11 and 12 power cycled, now OK.
- Gas gap disconnection:
- Gas gaps disconnected from HV or HV+gas.
- HV problem
- BOL.A3.05.CO.Ly1 HV channel trips due to BOL5A05.Ly1 chamber (the one that might have caused the many DAQ resyncs e-log).
- After debugging on both rack and chamber sides, a problem is found on the cable powering BOL5A05.Ly1 chamber.
- Built a splitter from the HV spider powering the BOL6A05.Ly1 chamber, but still trips due to electrical problems (checked that is not due to gas gaps).
- Serial number of the cable did not match due to swap between layers (the same serial number on the cable rack side is Ly1 but on the spider side is Ly0.
- In the end, BOL5A05.Ly1 disconnected (4 gas gaps) at spider level, before cavern intervention disconnected rack-side. To be followed up by Bologna technicians.
- BOF5C12.PI.Ly0 (4 gas gaps) disconnected from primary cable due to channel trip (DZ1 chamber driving high current at 7kV tripping the channel, DZ2 also driving high current). This chamber was connected before TS1.
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- BMS1C04.PI Vee trips at 6V, now fixed.
- BML1C03.PI Vee and Vpd OFF, fixed by board parameters reloading.
- BML3A11. CO. DP1LY0. DZ2 connector rebuilt.
- Canbus connector on the pad located on BOF3A14-confirm-toward sector-15 broken inside, replaced it.
- Vpad OFF for sectors 9 and 10 during TS1 due to 48PS failure, fixed.
- Disconnection moved from rack side to chamber side for the following gas gaps:
- BMS4A10.PI.Ly1 chamber driving high and instable current. Not possible to remove the overcurrent disconnecting DZ1 gaps, left disconnected rack-side. To be followed up by Bologna Technicians.
- BOL.B.09.CO.Ly0.RO HV reconnected on rack-side and BOL1A09 gaps (DZ1 and DZ2) disconnected on chamber side.
- Disconnection moved to chamber side for gas gap BOS5A10.CO.DP2.Ly0.DZ2 (difficul to reach, was skipped before). BOS5A10.CO.Ly0 chamber reconnected rack-side in HV channel BOS.A3.10.CO.Ly0.
- SPC4A04.CO.DP1.Ly1 and SPC4A04.CO.DP2.Ly1 giving a trigger hole reconnected to the HV (no Igap readout).
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Some gas gaps repaired from gas leaks [Dubna team].
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Missing hits in some trigger sectors in the feet regions, powering checks:
- BOF5C12.PI (s21_t4) Ly0: reconnected primary cable and one gas gap found disconnected and powered on but after some time trip on the HV channel, disconnected again.
- BOF3A12.PI (s54_t2) Ly0: reconnected one gas gap found disconnected and powered on but after some time trip on the HV channel, disconnected again.
- BOF5A14.PI (s57_t4) Ly0 and Ly1 missing hits: powering OK, everything seemed connected.
- Next top-priority intervention:
- Fix a LV Vee connector (no current for BOS5A02.CO Vee, with Vee powering FEs for 8 gas gaps, also causing BOS5A02 Vpd in overcurrent, after Friday intervention).
- See also the summary of cavern intervention for RPC trigger from Claudio [e-log]
- Communication issue on 2 mainframes, configuration rebooted [e-log]