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

Priority legend

• [A] High priority and/or easy to do
• [B] Medium priority and/or preferable to do
• [C] Low priority and/or can skip if too hard
• [d] Destructive. Might not be able to go back.

Preparations

• [A] Tune f1, f2, f3 frequencies to IMC FSR.

• [B,d] Replace all the in-vac steering mirrors and pick-off mirrors to proper ones JGW-T2112592

  • [C,d] Also POP and POS in-vac and in-air dichroic mirrors if necessary.
  • In the process of finalizing the specs

• [B,d] 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)
  • BSs arrived at Mozumi on June 30
• [B,d] 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

  • Items not yet purchased
• [A] Check actuation efficiencies of IMC mirrors, frequency actuation efficiencies of PSL.
• [B,d] Install picomotor+PZT steering mirrors for POP green and POS green.
  • Ordered on June 29
• [B] Install coil driver switch for ETMs (and ITMs?).
  • High power for lock acquisition, low power for low noise mode.
  • High power for ETMX and low power for ETMY is also possible, but anyway we need a switch to turn off the driver.
• [C,d] Install picomotors to center the beam on oplev QPDs and ASC QPDs.
  • Already PZT mirrors installed for some ASC QPDs?
• [C] Inject a fake RF signal to PDA1 to reproduce the spurious coupling around the REFL table and ALS racks
  • klogs 10958,10959, 11014, 11315, 12382, 12392,
  • Perhaps illuminating PDA1 by intensity modulated light maybe interesting.

  • Insert Baluns as necessary. LIGO-E1200148

  • Do other things also.
• [C] Check ground issues of RF PDs and RF QPDs.
• [B] Assemble optical table covers
  • IMC REFL: arrived, not assembled
  • TRX and TRY: ordered
  • AS: arrived, not assembled

Xarm

• [A] Measure the finesse at room temperature and at cryogenic temperatures, for both 1064 nm and 532 nm.
• [B] Measure the round-trip loss by taking into account the effect of birefringence correctly.
  • Measure the beam spot position dependence.
• [A] Measure the amount of POP/POS p-pol when the arm is locked and unlocked.
• [A] Measure the mode-matching for both 1064 nm and 532 nm.
• [B,d] Tune the Gouy phase separation between two QPDs at REFL/AS/TRX.
  • Make sure all the signals are in in-phase.
• [A] Measure the alignment sensing matrix at REFL/AS/TRX, for ITM and ETM.
  • Try closing ASC loops.
  • Check TRX IR QPDs.
• [A] Measure modulation depths for f1, f2 and f3.
• [A] Check ITM and ETM actuation efficiencies.
• [B] Make a power budget of each ISC detection port.
• [B] Refining the automation -- mainly for the successive full ifo initial alignment.
• [B] Leave a record on the demod phases -- for repeating the Schnup asymmetry measurement.
• [B] Establish IR/Green co-alignment procedure -- for full ifo initial alignment.
• [B] Could we check out the common mode servo board at this point?
• [A] Check new fiber noise cancellation system for ALS.
• [B] Goal of ALS: RMS of 1.7 Hz (CARM width)

Yarm

• Same as Xarm.

Michelson

• [A] Check BS actuation efficiency.
• [A] Check out the LSC optical gain. Should be easy enough to doublecheck.
• [A] Measure, again, the contrast defect.
• [C] Measure the mode content of AS beam using OMC.
• [B] Record typical Mich length noise.
• [B] Close the ASC loops -- mainly for the purpose of the initial alignment automation.
• [B] Refine the automation.

• [C] Check why the alignment procedure of Xarm->Yarm->PRMI is not good and we took Xarm->PRMI->Yarm. JGW-T2112594

  • Check beam spot positions on mirrors?

Power recycling cavity

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

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

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

Signal recycling cavity

• [A] Check actuation efficiency of SR mirrors.
• [A] Measure SRC Gouy phase.
• [B] Automation?

Dual Recycled Michelson

• [A] Measure power recycling gains for carrier and sidebands, with and without SRC.
• [B] 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.
• [B] Measure power at each ISC detection port when DRMI is locked.
• [B,d] Tune the Gouy phase separation between two QPDs at POP.
• [B] Measure the alignment sensing matrix at REFL/POP/AS.
  • Try closing ASC loops.
  • Most notably the f1-f2 WFSs at AS (RF QPD is already installed)

• [C] 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?
• [B] Refine automation.
• [B] Make a noise budget for MICH/PRCL/SRCL.

Fabry-Perot Michelson

• [B] Measure length sensing matrix.
• [B] Measure power at each ISC detection port when FPMI is locked.
• [B] Measure the alignment sensing matrix at REFL/POP/AS/TRX/TRY.
  • Try closing ASC loops.
  • Test out the radiation pressure basis actuation scheme (SOFT/HARD)
• [A] 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 (down to ~10 Hz) to AS port.
  • Also, rf phase and amp noises.
• [B] Measure the contrast defect, compare it with Michelson.
• [C] Measure the mode content of AS beam using OMC, compare it with Michelson.
• [B] OMC ASC commissioning?
• [C] Repeat the same measurements as described in
  • klogs 10958,10959, 11014, 11315, 12382, 12392,
  • to make sure whether the problem still persists or not.

Power Recycled Fabry-Perot Michelson

• [B] Measure length sensing matrix.
• [B] Measure power recycling gains for carrier and sidebands.
• [B] Measure power at each ISC detection port when PRFPMI is locked.
• [B] Measure the alignment sensing matrix at REFL/POP/AS/TRX/TRY.
  • Try closing ASC loops.
• [B] Refine automation.
  • Review/refine the O3GK lock acquisition process.
• [B] Measure frequency/intensity noise coupling, down to ~10 Hz.
• [B] Measure MICH/PRCL to DARM coupling.

Resonant Sideband Extraction

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