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

• 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.

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 TRX.
• 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.

Yarm

• Same as Xarm

Michelson

• Check BS actuation efficiency

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

Signal recycling cavity

• Check actuation efficiency of SR mirrors
• Measure SRC Gouy phase

Dual Recycled Michelson

• Measure power recycling gains for carrier and sidebands, with and without SRC.
• Measure length sensing matrix.
• Measure power at each ISC detection ports when DRMI is locked
• Measure the alignment sensing matrix at REFL/POP/AS.
  • Try closing ASC loops.

Fabry-Perot Michelson

• Measure length sensing matrix.
• Measure power at each ISC detection ports when FPMI is locked
• Measure the alignment sensing matrix at REFL/POP/AS/TRX/TRY.
  • Try closing ASC loops.

Power Recycled Fabry-Perot Michelson

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

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 ports when PRFPMI is locked
• Measure the alignment sensing matrix at REFL/POP/AS/TRX/TRY.
  • Try closing ASC loops.