Interventions on problematic Vpd channels (OVC)

• BMF2C14, Vth cable reconnected (resin injected chamber)

• BML6_GC07, Vth cable swapped in minicrate (back of rack)

• a few more chambers with unstable Vpd (OVC coming and going) have been checked but no evident problem was found

• Only chamber BOL4C07 has still Vpd with a stable OVC, but it is very difficult to reach

Swap checks [elog]

• SPC4C16.CO.DP2.Ly0.DZ1 gas gap in HV channel BMS.C.16.CO.Ly0 (DCS) confirmed to be actually connected to HV channel BMS.C.16.PI.Ly0 (cavern)
• SPC4C16.CO.DP1.Ly1.DZ1 gas gap in HV channel BMS.C.16.CO.Ly1 (DCS) confirmed to be actually connected to HV channel BMS.C.16.PI.Ly1 (cavern).

Recoveries of HV channels

• [elog] BMS.C.16.CO.Ly0 and BMS.C.16.CO.Ly1 HV channels were ramped down to 7000V and masked by expert (Daniela) on June 3rd, see e-log. The HV channels were ramped down by automatic scripts due to these problematic gas gaps driving high current:
  SPC4C16.CO.DP1.Ly0.DZ1, Igap, 2025.06.03 02:47 HvGapSafety (20.19 uA 9001V), Y_4603_X1_C1, BMS.C.16.CO.Ly0
  SPC4C16.CO.DP2.Ly1.DZ1, Igap, 2025.06.03 02:47 HvGapSafety (20.30 uA 9002V), Y_4603_X1_C1
  These gas gaps have been masked so that the HV channel does not ramp down automatically, even if they drive high current.
  BMS.C.16.CO.Ly0 and BMS.C.16.CO.Ly1 HV channels umasked and ramped up again. SPC4C16.CO.DP1.Ly0.DZ1 and SPC4C16.CO.DP2.Ly1.DZ1 gas gap masked.
• [elog] BME.B.13.CO.Ly1 HV channel was OFF due to BME4C13.CO.Ly1.DZ1 gas gap tripping the HV channel. It was not possible to reach the gas gap on chamber side to check the trip cause, so the disconnection of the gas gap was done on the rack side. Luckily, being BME, the HV cable rack side connected only one gas gap, so disconnecting a cable rack side meant disconnecting just one gas gap, the one that was actually tripping. BME.B.13.CO.Ly1 HV channel was put back on and check that it didn't trip anymore.
  BME4C13.CO.Ly1.DZ1 gas gap disconnected, BME.B.13.CO.Ly1 HV channel turned ON.