Overv rview of f KAGRA Masatake OHASHI (ICRR) on behalf of KAGRA - - PowerPoint PPT Presentation

Overv rview of f KAGRA

1 Overview of KAGRA

Masatake OHASHI (ICRR) on behalf of KAGRA collaboration

First of all …

KAGRA related talks

・Cryogenic system at underground site for Large-scale Cryogenic Gravitational Wave Telescope, KAGRA ・Vibration Isolation System for the Cryogenic Mirrors in KAGRA ・Interferometer control of KAGRA ・Global control using a laser strainmeter for KAGRA ・Construction and the operation of the interferometer control system and the DAQ system for KAGRA ・Investigation of the environment influence for the underground and cryogenic gravitational wave detector, KAGRA ・Detector Characterization for the underground-based gravitational-wave detector, KAGRA ・Newtonian noise from the underground water ・KAGRA Data Tiers ・Overview of KAGRA Data Analysis

2 Overview of KAGRA

This talk is an index of the 10 KAGRA related talks.

General outline of f KAGRA Pro roject

Purpose of this project ・To understand astronomical phenomena like supernova explosion and coalescence of binary compact stars with gravitational waves Project framework ・ICRR hosts this project, and KEK and NAOJ co‐host it to construct KAGRA for gravitational wave astronomy.

• Univ. of Toyama supports the project.

3 Overview of KAGRA

KAGRA is 3km L-shaped underground laser interferometer with cryogenic mirrors

Schedule of f KAGRA Pro roject

4 Overview of KAGRA

Calendar year 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Project start Tunnel Excavation iKAGRA bKAGRA

First operation 3km Cryogenic Interferometer Final installation Commissioning and Observation

iKAGRA

3km Michelson Interferometer

Designed sensitivity of KAGRA

5 Overview of KAGRA

Duty factor: > 80% Inspiral range: 153 Mpc

Two key features of f KAGRA

6 Overview of KAGRA

• 1. KAGRA is constructed at underground site.
• 2. KAGRA uses cryogenic mirrors.

Seismic noise in in Kamioka Mine

7 Overview of KAGRA

Seismic noise is serious for GW detection. Underground site Is very quiet. So we selected underground site for KAGRA.

Tunnel Excavation

8 Overview of KAGRA

3 corner stations are complicated because of tall towers for Vibration Isolation Systems.

Dif ifficulty of f Underground sit ite

9 Overview of KAGRA

Springwater

Spring water fr from wall surfaces

10 Overview of KAGRA

All surfaces were covered by waterproof sheets. It took 4 years to overcome spring water in the tunnel.

Two key features of f KAGRA

11 Overview of KAGRA

• 1. KAGRA is constructed at underground site.
• 2. KAGRA uses cryogenic mirrors.

Thermal noises

12 Overview of KAGRA

The sensitivity of interferometer around 100Hz is ordinarily limited by thermal noises.

Mirror th thermal noise

13 Overview of KAGRA

Amplitude of thermal noise is proportional to

(T/Q)1/2

In general, Q (inverse number of magnitude of dissipation) depends on T (temperature). Sapphire Q becomes highest at low temperature. Therefore KAGRA mirrors use sapphire substrates and are cooled to around 20K.

Cry ryogenic mir irror suspension system

14 Overview of KAGRA

~ 14 m

Cry ryogenic payload

15 Overview of KAGRA

type A

Cryogenic payload with mirror Mirror was cooled below 20K

In International Network for GW Observ rvation

16 Overview of KAGRA

GEO600 Advanced LIGO Hanford Advanced LIGO Livingston Advanced Virgo LIGO-India (anticipated) KAGRA

It is necessary to determine the direction of GW sources.

Jo Joint Run Planning wit ith LI LIGO and Vir irgo

17 Overview of KAGRA 17 KAGRA

KAGRA plans to join O3 in this year.

Summary

• In the spring of 2019, we completed the

construction phase and moved on to the commissioning phase.

• KAGRA plans to join O3 in this year.

18 18 Overview of KAGRA