This morning at 09:04:42 Mon 24mar2025 we had a BSC3 sensor gitch, which VACSTAT normally logs as a single gauge event and does not send alarms. Today however many LVEA gauges also tripped and alarms were sent to the Vacuum Team.
The reason is that on 13mar2025 we had a lock-loss due to an LVEA vacuum event which was below VACSTAT's nominal trip level. To counter this some LVEA slope trip levels were reduced from 1.0e-10 to 3.0e-12 (https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=83366)
Fast forward to today and the sequence was:
09:04:42 standard BSC3 sensor glitch, num_glitched = 1, all other gauges set to sensitive mode, meaning 3.0e-13 for most LVEA gauges
09:05:03 2nd LVEA sensor glitched on noise while in sensitive mode, num_glitched = 2, Alarms sent to Vacuum Team
09:11:07 3rd LVEA sensor glitched on noise while in sensitive mode
09:12:37 4th LVEA sensor glitched on noise while in sensitive mode
09:18:35 5th LVEA sensor glitched on noise while in sensitive mode
Vacstat code was changed to permit a sensitivity multiplier to be applied on a gauge-by-gauge basis. The multiplier for those LVEA gauges which have a 3.0e-12 slope trip was set to 1.0 (i.e. no additional sensitivity following a BSC3 trip). The increased sensitivity for the Delta-P trip level was retained.
prod.yaml
---
ifo: H1
glitch_monitor:
lookback_times: [60, 300, 600]
proc_period_secs: 10
vacuum_gauges:
default:
glitch_press_rate: [1.0e-10, 1.0e-10, 1.0e-10]
glitch_delta_press: [1.0e-08, 1.0e-08, 1.0e-08]
valid_value_min: 1.0e-10
valid_value_max: 1.0e-04
sensitivity_press_multiplier: 10.0
sensitivity_deltap_multiplier: 10.0
H0:VAC-LY_X0_PT100B_PRESS_TORR:
description: "Corner Station HAM1"
H0:VAC-LY_Y1_PT120B_PRESS_TORR:
description: "Corner Station BSC2"
glitch_press_rate: [3.0e-12, 3.0e-12, 3.0e-12]
sensitivity_press_multiplier: 1.0
H0:VAC-LX_Y8_PT132_MOD2_PRESS_TORR:
description: "Corner Station BSC3"
H0:VAC-LX_Y0_PT110_MOD1_PRESS_TORR:
description: "Corner Station HAM6"
H0:VAC-LY_Y3_PT114B_PRESS_TORR:
description: "Corner Station CP1"
glitch_press_rate: [3.0e-12, 3.0e-12, 3.0e-12]
sensitivity_press_multiplier: 1.0
H0:VAC-LX_X3_PT134B_PRESS_TORR:
description: "Corner Station CP2"
glitch_press_rate: [3.0e-12, 3.0e-12, 3.0e-12]
sensitivity_press_multiplier: 1.0
H0:VAC-LY_Y4_PT124B_PRESS_TORR:
description: "Corner Station Y-Arm"
glitch_press_rate: [3.0e-12, 3.0e-12, 3.0e-12]
sensitivity_press_multiplier: 1.0
H0:VAC-LX_X4_PT144B_PRESS_TORR:
description: "Corner Station X-Arm"
glitch_press_rate: [3.0e-12, 3.0e-12, 3.0e-12]
sensitivity_press_multiplier: 1.0
H0:VAC-MY_Y1_PT243B_PRESS_TORR:
description: "Mid-Y Y1 Beam Tube"
H0:VAC-MY_Y5_PT246B_PRESS_TORR:
description: "Mid-Y Y2 Beam Tube"
H0:VAC-EY_Y6_PT427_MOD1_PRESS_TORR:
description: "End-Y Y6 BT Ion Pump"
H0:VAC-EY_Y1_PT423B_PRESS_TORR:
description: "End-Y Beam Tube"
H0:VAC-EY_Y3_PT410B_PRESS_TORR:
description: "End-Y BSC10"
H0:VAC-MX_X1_PT343B_PRESS_TORR:
description: "Mid-X X1 Beam Tube"
H0:VAC-MX_X5_PT346B_PRESS_TORR:
description: "Mid-X X2 Beam Tube"
H0:VAC-EX_X6_PT527_MOD1_PRESS_TORR:
description: "End-X X6 BT Ion Pump"
H0:VAC-EX_X1_PT523B_PRESS_TORR:
description: "End-X Beam Tube"
H0:VAC-EX_X3_PT510B_PRESS_TORR:
description: "End-X BSC9"