Minute of PEM meeting

• Date: 2019/6/11 16:00-18:00(JST)
• Attendance: Yokozawa, Washimi, Miyo, Kozakai, Oshino, Mori, Miyoki, Okawa, Fujikawa, TTanaka, Kaihotsu, Kokeyama
• Expand meeting

=== Agenda ===

• PEM status (Yokozawa) (10min)
  • 2nd installation was almost finished, need the check of the chamber PEMs
• Virgo PEM measurements (Yokozawa) (10min)
  • Sound decay measurement
  • IYC chamber characterization
  • Comparison between Virgo and KAGRA
• Characterization of the EXC chamber (Washimi) (10min)
  • Why EXC? Removed the cryopayload and prepared ADC. Additional measurement by IYC
  • FFU on/off
  • Around 1Hz from cooler, 20.45, 30.62, 60.94, ... No problem to KAGRA sensitivity
  • Evaluate the magnetic field by simulation after closing the chamber.
  • Acoustic measurement, 13-59Hz and more than 1kHz from cooloer. (also, about 10kHz with 2Hz frequency)
  • Coherence observed from only the fan
  • 2Hz did not appear at the chamber accelerometer
  • X-end PEM models
  • Before/After cooling down
  • 0.5 deg increasing by the ondotori
  • Thunderstorm was detected by magnetometer, gorogoro
  • DC supply no significance difference before/after cooling
  • mag 1,3Hz appear
  • sound some line appear, but FFU was on.
• Power supply monitors (Washimi) (10min)
  • DC power monitor for the 18/24V
  • noise floor is limited by ADC noise
  • 60Hz was observed
  • 100Hz AC was quite dirty
  • Need the more safety AC monitor
  • We need to focus the power supply issue continuously
• Acoustic and magnetic field measurement (Kaihotsu) (10min)
• Current PEM measurements (Mori) (10min)
• Ground motion (Miyo) (10min)
• Sound injection (TTanaka) (10min)
• PEM injection plan (TTanaka) (10min)
• Kozapy+ (Kozakai) (20min)

• Report from DetChar (Yamamoto, Kokeyama) (10min)

• Summary and future prospect (Yokozawa) (10min)