Satellite Meeting on Future Upgrade of KAGRA

Main F2F Page

Date/Time/Venue

August 21th (Wed.) 13:00 - (We would like to finish the main discussions by 15:30, when the KAGRA site tour starts)

Venue: Multi purpose room (多目的ホール), Faculty of Science, University of Toyama, Gofuku Campus

(Note that different from the venue of F2F meeting, Kuroda hall)

Zoom(2) connection: https://zoom.us/j/6676627462

Anyone are welcome to join the discussions on site or via online and for even those who didn't make a registration.

Related information

• FPC wiki

• FPC White Paper

Program

Agenda

• Things happened since the last satellite meeting

  • O5 plans (A+,AdV+) and schedule are released to public

  • Schedule of 3G (ET, CE) released in GWADW 2019

  • A new proposal ozGrav-HF

  • iLM submitted a proposal to produce large sapphire bulk up to 200~250 kg and aiming low heat absorption (< 10ppm/cm)

  • ITM birefringence issue found (e.g. JGW-G1910369)

  • Science study updated by A.Nishizawa JGW-G1909934 by considering LVK network

• We would like to get agreement/understanding on the followings:
  • Publication on the KAGRA future upgrades
  • Define the ultimate goal in long term towards 2030's
  • More realistic plans for O5
• Publication plan (Full KAGRA author)
  • Serve as the 2nd release of the white paper
  • Discussion about the ultimate goal and intermediate plants including O5
  • Share the same idea inside the collaboration as well as to inform it to LV and near-by communities
  • Submission/publication target just after KAGRA manage to join O3 (late 2019~early 2020 ?)

  • Target journal: PRL or PRD ? (depending on the number of pages/figures) c.f. iKAGRA => PTEP, bKAGRA-ph1 => CQG

• Ultimate goal of KAGRA
  • Time scale around 2030
  • It should fill the gap between O5 and 3G
  • 200 kg Sapphire as the primary candidate (iLM may help us a lot if their proposal is accepted)
  • Backup plan with Silicon ? Decision tree should be prepared

  • With 200 kg sapphire and 500 W laser, 500 Mpc may be possible JGW-G1910533

  • What is the name ? Naming is important: hKAGRA ? (hyper-KAGRA, or h as Heavy-mass and High-power), uKAGRA ? (ultimate-KAGRA) or dKAGRA ? (dream-KAGRA)
• More realistic plans for O5
  • Due to the ITM issues it may be difficult to achieve the design sensitivity during O4
  • One option is to achieve the design sensitivity (with detuning) of 150 Mpc in O5
  • Detuning doesn't go well with squeezing. Should we give up detuning but BRSE with FD squeezing (60m filter cavity ?)

  • High Freq. (HF) upgrade requires R&D and change of suspensions which may have a risk to worsen the sensitivity, while FD squeezing can be installed independently so that we can go back to detuning option if the installation of squeezing doesn't finish in time