LCGT Project Status

EGO-ICRR Meeting4 October 2011

@ University of TokyoSeiji Kawamura (ICRR)

Objectives of LCGT

• Detect gravitational waves together with Virgo and LIGO for the first time

• Establish Gravitational Wave Astronomy• Establish multi-messenger observations

between GWs and Electromagnetic waves/Cosmic rays

Expected GW sources• Neutron star binary

coalescence– correlation with GRB

• Black hole binary coalescence

• Black hole ringdown• Supernovae– Correlation with Neutrino

• Pulsar• Early universe• Unknown

Key Features of LCGTUnderground Cryogenic mirrors/

suspensions

These are essential features for the 3rd GW detectors such as ET.

Underground Site

We are here.

Ground motion in Kamioka mine

Advantage of Underground Site

• Not only linear effect• But also nonlinear effect

Smaller low-frequency motion of mirror Lower gain of control system necessary Lower in-band noise imposed by control system

Sensitivity Comparison

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20m prototype was moved from Tokyo to Kamioka in 1998.

@ Tokyo

@ Kamioka

Cryogenics System

Baffles Thermal Shield Pulse Tube Cryocooler

Inner Wall (8K)Platform (14 K)Upper Mass (15 K)Mirror (20 K)Flexible Heat Link

Sapphire Mirror

Sapphire mirror at 20 K• Transparent at 1064 nm• Low thermal noise– High Quality factor at 20 K

• Low thermoelastic noise– High thermal conductivity at 20 K– Low thermal expansion coefficient at 20 K

Seismic Attenuation System (SAS) for LCGT

Tunnel (2nd floor)ChamberInverted Pendulum

GAS Filter(invented by DeSalvo)

Tunnel (1st floor)ChamberMirror SAS was designed based on

the Virgo SA.

Goal Sensitivity of LCGT

External Review

• Feb. 28 – Mar. 4, 2011 @ICRR• Almost all the subsystems were reviewed• Review items:– Requirements– Design – Schedule– Prototype test plan– Etc.

ReviewersName Affiliation Remarks

Stefan Ballmer LSC/ Syracuse University

Alessandro Bertolini LSC/ Albert-Einstein-Institut Hannover

Raffaele Flaminio Virgo/ Laboratoire des Matériaux Avancés

Andreas Freise GEO/ University of Birmingham

Warren Johnson LSC/ Louisiana State University

David Ottaway ACIGA/ University of Adelaide

Benno Willke GEO/ Leibniz Universität Hannover

Michael E. Zucker LIGO-Lab/ Massachusetts Institute of Technology Chair

Seiji Kawamura LCGT/ ICRR, NAOJ Chief of secretariat

Masaki Ando LCGT/ Kyoto University Deputy chief of secretariat

Report

• We obtained report on March 10, 2011• 12 pages• Consists of:– Executive summary– Recommendations to management– Recommendations to each subsystem

Executive Summary 1

focusing interferometer noise optimization (and corresponding astrophysics goals) to capitalize on the unique advantages of the underground site and cryogenic operation

Bandwidth working group (led by K. Somiya) was convened to discuss this. It turned out that shifting the frequency band lower will not gain significant advantages.

Executive Summary 2

establishing a strong Systems group to insure subsystem interfaces and design goals are properly distributed, and sufficient, but not excessive

Systems Engineering Office has been created.

Executive Summary 4 & 5

wherever feasible, employing (or at least starting with) established, tested component designs requiring minimal modification; proceeding rapidly toward integrated system testing (e.g., through enhanced scope for the iLCGT phase) to minimize the risk of late surprises

Roadmap working group (led by M. Ando) was convened to discuss this. We decided to employ a simple isolation system for iLCGT and meanwhile to develop SAS at the site.

Program Advisory Board

• Jun. 21 – 22, 2011 @ICRR• Review items:– Management– Schedule– Design– Etc.

ReviewersName Affiliation Remarks

Masanori Iye NAOJ, Extremely Large Telescope Project Office

David McClelland ACIGA, ANU

Benoit Mours Virgo, LAPP Annecy

Takashi Nakamura Department of Physics II, Kyoto University

Bernard Schutz GEO, AEI, Potsdam

Gary Sanders Thirty Meter Telescope project

Akira Yamamoto KEK, Cryogenics Science Center

Stan Whitcomb Caltech Chair

Report• We obtained report on August 30, 2011• 6 pages• Consists of responses to the following points:

– If the management and organization of the project are OK.– If the construction status & plan are OK.– If the scientific goals are reasonable.– What should be improved in the LCGT construction?– Whatever the advice for this project.

• Actions:– We have started discussing possible actions to the report.

Schedule of LCGT2011 2012 2013 2014 2015 2016 2017

bLCGTiLCGT

Observation

iLCGT bLCGT

Temperature Room Cryogenic

Vibration isolation Stack and triple pendulum SAS

Interferometer Fabry-Perot Michelson Resonant sideband Extraction

Organization of LCGTLCGT Council Director

(Kajita)Program

Advisory Board

Systems Engineering Office(Kawamura, Ando,

Miyoki, Somiya)

Executive Committee( Nakatani (PM), Kuroda, Ohashi, Kawamura, Mio,

Ando)

Executive Support

DATA Analysis

Cryogenics

Input/Output Optics

Tunnel Facility Vibration isolationVacuum

Mirror

Laser

Main interferometer

Auxiliary optics

Digital system

Geophysics Interferometer

Analog Electronics

Subsystem

Joining the worldwide GW network

Advanced Virgo

LCGTAdvanced LIGO GEO-HF

LCGT will join the world network of gravitational wave detectors, with full reciprocal sharing of data with the Virgo collaboration, the LIGO Collaboration and the GEO600 Collaboration at a time determined by mutual agreement of all parties - LCGT, Virgo, LIGO, and GEO.

LCGT in network

L/H+L/L+V 50% L/H+L/L+V+LCGT 50%

B. F. Schutz

LIGO(H)+LIGO(L)+Virgo

Coverage at 0.5 M.S.: 72% 3 detector duty cycle: 51%

LIGO(H)+LIGO(L)+Virgo+LCGT Max sensitivity (M.S.): +13% Coverage at 0.5 M.S.: 100% 3 detector duty cycle: 82%

Dawning of Gravitational

Wave Astronomy is

near!

Illustration:

Sora