Sheila, Naoki, Vicky - SQZ OMC mode scans with cold OM2

• 76mW seed power launched on SQZT0, and OPO = LOCKED_SEED_DITHER + FC = MISALIGNED:
  • To start, we measured opo ir seed trans power on sqzt7: OPO_IR_PD_LF_OUTPUT = 0.876mW, and OPO_IR_PD_DC_POWERMON = 0.888 mW. PD calibration LHO:72761, Sept 2023.
    • After seed dither locking at 1387039858, opo ir trans increased ~1% in the first 5 min and settled.
• Open SQZ beam diverter, align SRM, misalign SR2, open ham6 fast shutter.
  • immediately,  ASC-AS_A_DC_NSUM_OUT16 = 19,  ASC-AS_B_DC_NSUM_OUT16 = 51-52.  ASC-AS_C_NSUM_OUT16 = 680e-6.
• Engaged DC{3/4} centering loops - just worked. Will leave DC3/4 on for mode-scans.
  • This aligned ASC-AS_{A/B}_DC_NSUM_OUT16 to 51 counts both. On OMC QPD's, ASC-OMC_{A,B}_NSUM_OUT16 are each ~630e-6.
• OMC ASC master gain "one click up" to 0.025.
• Lock OMC on SQZ beam. (scan OMC PZT2, find max, set trigger value to 0.1, manual OMC guardian: DOWN, ASC_QPD_ON, PREP_LOCK_OMC, OMC_LSC_ON, OMC_LOCKED. Freeze OMC ASC. Manual optimize alignment using OM3/OMC sliders.)
• Take 1 minute "LOCKED" time.
• Turn off OMC LSC servo (input,output). Move OMC PZT off-resonance, take 1 minute "UNLOCKED" time.
• Take OMC mode scan (run DTT template).

Taking SQZ-OMC mode scans, using DTT template saved in $(userapps)/sqz/h1/Templates/dtt/OMC_SCANS/Dec19_2023_PSAMS_OMC_scan_coldOM2.xml

PSAMS 200/200, cold OM2

• Locked: 1387045702 + 60 seconds.  OMC_DCPD_SUM_OUT_DQ~0.476.
• Unlocked: 1387045917 + 60 seconds.
• Mode-scan (ref 30) cyan. 19/12/2023 18:32:56 UTC (1387045994) + 200 seconds.

PSAMS 120/120, cold OM2

• Locked: 1387047076 + 60 seconds.  OMC_DCPD_SUM_OUT_DQ~0.465.
• Unlocked: 1387047200 + 60 seconds.
• Mode-scan (ref 31) pink. 19/12/2023 18:55:33 UTC (1387047351)+ 200 seconds.

Dark

• Dark noise: Turned off DC centering, fast shutter, sqz beam diverter.
• Dark: 1387048209 + 60 seconds.