ISC Meeting on 2017/9/11 14:00 - 15:00

Participants: (eZuce meeting)

Next meeting

2017/10/23 14:00 - 15:00 (we might have another meeting if necessary by then)

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Minutes

bKAGRA sensitivity update [Komori] JGW-T1707038
- thermal noise calculation error corrected, substrate absorption 50ppm/cm (measured value 30ppm/cm was not used because of measurement error and safety margin; 50ppm/cm was the required value)
- Approved by KSC, passed to EO on Sept 6
bKAGRA Phase 1 [Michimura]
- no PRMI operation after Phase 1
- initial alignment work starts on Sept 25
  - Masayuki Nakano will lead the initial alignment
  - Sept 25-29: PR alignment
  - Oct 2-6: alignment to EX
  - Oct 10-13: alignment to EY
  - Oct 16-: beam profiling if necessary
- AS optics
bKAGRA Phase 2 schedule [Michimura] JGW-T1707079
- meeting with SEO on Sept 6
- Goal: 1 hour lock of cryogenic RSE with RF readout, probably with ASC, no sensitivity goal
- input laser power not decided
- when to swap ETM, SRM reflectivity, vacuum
- schedule adjustment between AS WFS and OMC test necessary
SRM reflectivity for early phase of bKAGRA [Enomoto] JGW-G1707078
IMMT1 and IMMT2 trasmission [Michimura,Takeda]
- IMMT2 transmission optics are too much squeezed
IR/green steering mirrors [Michimura]
- will arrive at Mozumi on Sept 6
DC QPD holder [Michimura]
- beam height should be 4inch to use similar mount, with small modification of spacer (instead of 3inch in JGW-D1402607)
  - RF PD, RF QPD boxes are designed for 4inch beam height
- stages are not needed for ISC DC QPD
- design new ones; they can be very simple [-> Michimura?]
- calibration can be done in different ways
- put strain relief and anchors for cables to protect QPD board
OMC and OFI [Somiya]
- look for OFI with larger aperture [Somiya]
- DC PD and DC QPD [Michimura]
PSL EOM Layout re-consideration [Enomoto] (JGW-T1706748)
- Delay-line length decided to be 2.66 m (instead of 8.88 m)
- Modulation phase between f1 AM and PM is always aligned (we need this to be aligned)
- Modulation index needed at each EOM is less than measured maximum index by Uehera (JGW-T1605611)
- Optickle simulation by Kohei Yamamoto
  - simulation on imperfections (MZ arm asymmetry, MZ lock, EOM phase difference control etc.)
  - start with hand calculation, simple setups, and then to full IFO simulation
- Requirement on carrier power loss?
- Comment from Stefan Ballmer
  - Similar calculation was done in LIGO in the past. Displacement noise requirement for MZ was tough (~1e-14 m/rtHz).
  - Any in-air interferometer suffer from jitter and frequency noise which cannot be suppressed.
Actuator noise modeling [Michimura,Miyamoto] (JGW-T1503453)
- Summarized in the paper JGW-P1707051
  - waiting for Type-A seismic transfer function update [Okutomi]
- Needs to implement frequency noise, but FSS modeling with ALS is complicated [student!]
- Discuss mirror vibration from heat link
  - Meeting on July 14 [Yamada, Miyamoto, Ushiba, Michimura]

See this page for other agendas.