O4 Commissioning Task List

This is a list of things to do for each commissioning stage for O4.

Each stage include ASC.

References

• klog review during O3 commissioining JGW-E2112729

• Summary of Optical Characterization

• Commissioning (IOO): Evaluation meeting JGW-G2112491

• MIF Schedule Estimate for bKAGRA Phase 2 JGW-T1707079

• Definitions for the X arm commissioning JGW-T1808343

• Definitions for the DRMI commissioning JGW-T1909573

Preparations

• Tune f1, f2, f3 frequencies to IMC FSR

• Replace all the in-vac steering mirrors and pick-off mirrors to proper ones JGW-T2112592

• Replace all the beam splitters in in-air optical tables to non-polarizing beam splitters JGW-D2112956

  • This is necessary to estimate the polarization content of the interferometer correctly (without too much confusion)
• Install polarization optics to backward POP or POS, and TRY and TRY.

  • This is necessary to estimate the arm cavity round-trip loss correctly JGW-T2011633

• Check actuation efficiencies of IMC mirrors, frequency actuation efficiencies of PSL.
• Install picomotor+PZT steering mirrors for POP green and POS green.
• Install coil driver switch for ETMs (and ITMs?).
  • High power for lock acquisition, low power for low noise mode.
• Install picomotors to center the beam on oplev QPDs and ASC QPDs.

Xarm

• Measure the finesse at room temperature and at cryogenic temperatures, for both 1064 nm and 532 nm.
• Measure the round-trip loss by taking into account the effect of birefringence correctly.
  • Measure the beam spot position dependence.
• Measure the amount of POP/POS p-pol when the arm is locked and unlocked.
• Measure the mode-matching for both 1064 nm and 532 nm.
• Tune the Gouy phase separation between two QPDs at REFL/AS/TRX.
  • Make sure all the signals are in in-phase.
• Measure the alignment sensing matrix at REFL/AS/TRX, for ITM and ETM.
  • Try closing ASC loops.
• Measure modulation depths for f1, f2 and f3.
• Check ITM and ETM actuation efficiencies.
• Make a power budget of each ISC detection port.
• Refining the automation -- mainly for the successive full ifo initial alignment.
• Leave a record on the demod phases -- for repeating the Schnup asymmetry measurement.
• Establish IR/Green co-alignment procedure -- for full ifo initial alignment.
• Could we check out the common mode servo board at this point?

Yarm

• Same as Xarm.

Michelson

• Check BS actuation efficiency.
• Check out the LSC optical gain. Should be easy enough to doublecheck.
• Measure, again, the contrast defect.
• Record typical Mich length noise.
• Close the ASC loops -- mainly for the purpose of the initial alignment automation.
• Refine the automation.

Power recycling cavity

• Measure PRY length and PRX length.
  • Previous methods give inconsistent results and also not compatible with Schnupp asymmetry measurements.
• Tune IMC length to PRC length (and re-tune sideband frequencies).
• Check actuation efficiency of PR mirrors.
• Measure PRC Gouy phase.
• Close the ASC loops.
• Refine the automation.
• Check out the power build up in the carrier-locked and side-band locked conditions

• Correlation measurement of p/s-pol sloshing (https://klog.icrr.u-tokyo.ac.jp/osl/?r=9333) against angular fluctuations or whatever.

• Identification of any drifty suspensions as the carrier is locked -- to support the coming full lock operation.
• Tune up the triggers and filter shapes for fast lock acquisition.

Signal recycling cavity

• Check actuation efficiency of SR mirrors.
• Measure SRC Gouy phase.
• Automation?

Dual Recycled Michelson

• Measure power recycling gains for carrier and sidebands, with and without SRC.
• Measure length sensing matrix.
  • Both for 1f and 3f signals.
  • Optimize the modulation depths if necessary for sufficient signal-to-noise ratio for 3f signals.
• Measure power at each ISC detection port when DRMI is locked.
• Tune the Gouy phase separation between two QPDs at POP.
• Measure the alignment sensing matrix at REFL/POP/AS.
  • Try closing ASC loops.
  • Most notably the f1-f2 WFSs at AS

• Examine the mode-hop criteria (https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=12213)

  • Which mirror affects most and how much angular motions are tolerable?
  • Is the SRC Gouy phase large enough?
• Refine automation.

Fabry-Perot Michelson

• Measure length sensing matrix.
• Measure power at each ISC detection port when FPMI is locked.
• Measure the alignment sensing matrix at REFL/POP/AS/TRX/TRY.
  • Try closing ASC loops.
  • Test out the radiation pressure basis actuation scheme
• Do some noise hunting at low frequencies and VIS commissioning with FPMI
  • Perhaps interesting to lock OMC to check out the freq/int noise couplings to AS port.
  • Also, rf phase and amp noises.
• OMC ASC commissioning?

Power Recycled Fabry-Perot Michelson

• Measure length sensing matrix.
• Measure power recycling gains for carrier and sidebands
• Measure power at each ISC detection port when PRFPMI is locked.
• Measure the alignment sensing matrix at REFL/POP/AS/TRX/TRY.
  • Try closing ASC loops.
• Refine automation.
  • Review/refine the O3GK lock acquisition process.

Resonant Sideband Extraction

• Measure length sensing matrix.
• Measure power recycling gains for carrier and sidebands
• Measure the cavity pole
• Measure power at each ISC detection port when PRFPMI is locked.
• Measure the alignment sensing matrix at REFL/POP/AS/TRX/TRY.
  • Try closing ASC loops.