Status of the Large-scale Cryogenic Gravitational Wave Telescope Project KAGRA Kazuhiro Yamamoto on behalf of KAGRA collaboration Department of Physics, University of Toyama 2017 September 13 The meeting of Physical Society of Japan @Mine campus, Utsunomiya University, Utsunomiya, Tochigi 1 1 1 1

Gravitational wave 1916 : A. Einstein predicted gravitational wave (General relativity) A. Einstein(Wikipedia) 2015 : LIGO detected gravitational wave directly. LIGO open science center 2 2 2 2 2 2 2 2

In last two years What happened so far ? Observation period O1 : 2015 Sep 12- 2016 Jan 19 O2 : 2016 Nov 30 - 2017 Aug 25 Three events (binary black hole coalescences) Physical Review Letters 116(2016)061102. Physical Review Letters 116(2016)241103. Physical Review Letters 118(2017)221101. Virgo joins O2 (2017 Aug 1 - 25) LIGO and Virgo have one year break for improving. 3 3 3 3 3 3 3 3

After O2 LIGO Scientific Collaboration News 25 August 2017 -- The Virgo and LIGO Scientific Collaborations have been observing since November 30, 2016 in the second Advanced Detector Observing Run ‘O2’ , searching for gravitational-wave signals, first with the two LIGO detectors, then with both LIGO and Virgo instruments operating together since August 1, 2017. Some promising gravitational-wave candidates have been identified in data from both LIGO and Virgo during our preliminary analysis, and we have shared what we currently know with astronomical observing partners. We are working hard to assure that the candidates are valid gravitational-wave events, and it will require time to establish the level of confidence needed to bring any results to the scientific community and the greater public. We will let you know as soon we have information ready to share. http://www.ligo.org/news.php 4 4 4 4 4 4 4 4

Next step (1)Better sensitivity : Plans for 3rd generation (10 times better sensitivity than current 2nd generation) (2)Many other detectors for finer direction resolution KAGRA : 2nd generation detector in Japan (Kamioka) Unique key features : Underground site with small seismic motion Cooled mirror and its suspension to reduce thermal noise -> 3rd generation adopts these idea. 5 5 5 5 5 5 5 5

KAGRA timeline Phase 2 Phase 1 300K 6 6 6 6 6 6 6 6

BNS inspiral range [Mpc] 感度の進展予想 Y. Michimura 13aS35 2 KAGRAはどのように感度を上げていくか？ LIGO Voyager(米) 1000 どのように世界一を目指すか？ どのようにいち早く 重力波観測に加わるか？ upgrade KAGRA+? design AdV+? O3 design BNS inspiral range [Mpc] aLIGO(米) O2 design 100 O1 O3 AdV(欧) O2 KAGRA(日) 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 7 year Based on Living Reviews in Relativity 19, 1 (2016) 7 7 7 7 7 7 7 7

Vibration isolation and cryostat Vacuum ducts along laser beam Design drawing with tunnel and cross section 2nd floor A. Hagiwara 14 m Shaft Clean booth Vacuum ducts along laser beam Cryostat 8 8 8

Vibration isolation and cryostat A. Hagiwara Vibration isolation system (room temperature) Cryogenic payload (Mirror is on bottom side of payload) 9 9 9

Vibration isolation and cryostat Finally, we installed this vibration isolation and cryogenic payload (almost same as practical one) at one end station. A. Hagiwara Vibration isolation system (room temperature) Cryogenic payload (Mirror is on bottom side of payload) 10 10 10

Vibration isolation and cryostat Cryogenic payload Mirror and payload was cooled down (12K, initial cooling time is 23 days). A part of vibration isolation 11 11 11

Cryogenic payload Vibration measurement T. Ochi 13pU34 2 Performance test T. Miyamoto 13pU34 4 Heat link T. Yamada 13pU34 3 Mirror 12 12 12

Sapphire mirror Absorption in mirror M. Manuel 14aU11 11 Mirror contamination (residual gas) K. Hasegawa 13pU34 5 Ears bonding to suspend mirror T. Ushiba 13pU34 1 13 13 13

Vibration isolation R. Takahashi 13aS35 3 A. Shoda 13aS35 5 M. Barton 161207_SAITO BRT Type-A system ETM bKAGRA phase-I (- Mar 2018) - Cryogenic test mass Sapphire, 23kg, 20K - Tall seismic isolator IP + GASF + Payload Y-arm R. Takahashi 13aS35 3 ITM MC PRM BS X-arm Type-C system BRT IO - Mode cleaner Silica, 0.5kg, 290K - Stack + Payload ITM ETM Type-Bp payload Test mass and Core optics (BS, FM,..) Silica, 10kg, 290K - Seismic isolator Table + GASF + Type-B Payload A. Shoda 13aS35 5 Type-B system SRM - Core optics (BS, SRM,…) Silica, 10kg, 290K - IP + GASF + Payload - Stack for aux. optics OMMT OMC M. Barton 13aS35 4 14 14 14

Current status of VIS Type-A Y-End: Installed. Cooling test of the cryogenic payload is on going. X-End: Installation work is on going. Setting the Filter1 stage now. Type-B BS test hanging was finished. Real BS installation is on going. Type-Bp PR2 & PR3 have been installed. PRM installation is on going. Bottom filter and dummy payload in Y-end. BS payload with assembly frame. Installation of PR2. 15 15 15

Vibration isolation and ground motion Crackling noise in vibration isolation system M. Kirii 13pU34 12 We try to measure Crackling noise on KAGRA suspension. ・We assembled new measuring system in KAGRA mine. ・We found that the noise is reduced in the low frequency range compared to the measurement in Kashiwa. Compensation of slow motion of ground K. Miyo 13aS35 6 16 16 16

Component of interferometer 161207_SAITO IO MC ETM ITM Y-arm X-arm BS SRM PRM BRT OMC OMMT Transmission monitor system T. Akutsu on behalf of T. Morozumi 13aS35 7 Intensity stabilization Green lock University of Toyama BRT Output mode cleaner J. Kasuya 13aS35 8

Intensity stabilization Achieved noise reduction 　30dB @ 30Hz 　35dB @ 100Hz University of Toyama

Intensity stabilization University of Toyama

Green lock University of Toyama PD 40Mhz EOM Optical fiber SHG AOM PDH PD 40Mhz EOM Optical fiber PLL SHG AOM Laser 2 PD PR2 BS X-Armcavity Laser 1 PR3 University of Toyama

Experiment of PLL system Green lock Experiment of PLL system University of Toyama Beatnote Frequency divider Beatnote is locked at 129MHz

Component of interferometer 161207_SAITO IO MC ETM ITM Y-arm X-arm BS SRM PRM BRT OMC OMMT Transmission monitor system T. Akutsu on behalf of T. Morozumi 13aS35 7 Intensity stabilization Green lock University of Toyama BRT Output mode cleaner J. Kasuya 13aS35 8

Transmission monitor system T. Akutsu on behalf of T. Morozumi 13aS35 7

Component of interferometer 161207_SAITO IO MC ETM ITM Y-arm X-arm BS SRM PRM BRT OMC OMMT Transmission monitor system T. Akutsu on behalf of T. Morozumi 13aS35 7 Intensity stabilization Green lock University of Toyama BRT Output mode cleaner J. Kasuya 13aS35 8

アウトプットモードクリーナ Output mode cleaner J. Kasuya 13aS35 8 講演タイトル：KAGRA用アウトプットモードクリーナの開発V (東工大 粕谷) 出射光学系のレイアウトを決定 OMC防振装置の要求値を計算 OMC用の板バネを開発 Output mode cleaner J. Kasuya 13aS35 8

Calibration Calibration is always crucial point in experiments ! Calibration of gravitational wave detector : < 1% Photo calibrator shakes mirror for calibration. (Back action (momentum) of reflected light). Overview Y. Inoue 13aS35 11 26 26 26

Power modulation Camera (beam spot) Bin-Hua. Hsieh. T. Shishido 13aS35 12 Camera (beam spot) T. Shishido 13aS35 13 27 27 27

Calibration How to calibrate with calibrator ? Signal injection test T. Yokozawa 13aS35 11 Calibration in iKAGRA T. Yamamoto 13aS35 10 28 28 28

Data transfer

99.99 % のファイルを 1 s 以内に大阪市立大学へ転送可能 Data transfer 転送システム性能評価(2)：結果 坑内から大阪市立大学への転送遅延の累積相対度数分布 99.99 % のファイルを 1 s 以内に大阪市立大学へ転送可能 K. Sakai 13pU34 6

Data analysis Test run Data analysis is in progress. 300K 31 31 31 31

Binary coalescence search and correlation analysis H. Yuzurihara 15aU31 1 M. Sasai 15aU31 2 Noise characterization

Summary Gravitational wave was detected. We need more detectors for astronomy : KAGRA bKAGRA phase 1 : by March 2018 Cryogenic Michelson interferometer operation We strongly proceed with preparation, installation, development, and investigation. Details of KAGRA are presented today. Some talks will be tomorrow or the day after tomorrow. 33

Thank you for your attention ! 34