2019/5/21 15:00-16:00 Weekly commissioning meeting topics

• Zoom URL: https://zoom.us/j/6676627462

• Assignment of staffs

  • https://teamup.com/kswnmta8p18h6u1uab

Schedule

• 5/14: RT PC maintenance -> go to safe mode for all VIS connected Dolphin (BS, )

• 5/17~ increasing ETMY temperature.
• 5/20-24: Exchanging cryo valves.
• Xend

  • 5/2: Cooling start

  • 5/29: Cooling done
• End of April~: Y arm commissioning
• ~End of May: Y arm and FPMI commissioning

Discussion

Low finesse issue on Y arm

• Status as of now
  • 2019/5/17(Thu)
    • X-arm:
      • Finesse = 1399
      • Power build-up factor = 891
      • Ring-down half-life = 3.11msec
      • REFL POWER locked/unlocked = 0.96
    • Y-arm:
      • Finesse = 28
      • Power build-up factor = 18
      • Ring-down half-life = 0.42msec
      • REFL POWER locked/unlocked = 0.50 (agrees with experiment)
  • 2019/5/17(Thu)
    • Finesse of Yarm for green: 17 (design 50)
  • 2019/5/17(Fri)
    • Finesse of Yarm for IR: 120, ETMY temperature 33K
  • 2019/5/19(Sun)
    • Finesse of Yarm for IR: 146, ITMY temperature 25K, ETMY temperature 51K
  • 2019/5/20(Mon)
    • Finesse of Yarm for IR: 131, ITMY temperature 25K, ETMY temperature 60K
    • Finesse of Xarm for IR: 1151(probably due to the miscentering), ITMY temperature 29K, ETMY temperature 126K, but alignment at ETMX
• Cryo status and plan
  • ETMY
    • 5/17~: tuned off ETMY cryostat cooler
    • 5/24PM~ inject 100Pa Nitrogen to increase temperature. It takes several days close to room temperature ?? degree.
    • 5/27 evacuation of Nitrogen.
  • ITMY
    • 5/23AM~: tuned off cryostat cooler, finesse measurement for Yarm
  • ITMX
    • 5/22AM~: tuned off cryostat cooler, finesse measurement for Xarm
• Chance for Y arm finesse measurement: 5/21, 5/23
  • Searching good spot on Yarm