Gravitational wave 1916 A Einstein predicted gravitational wave

Gravitational wave 1916 : A. Einstein predicted gravitational wave (General relativity) A. Einstein(Wikipedia) 2015 : LIGO detected gravitational wave directly. By November 2017, papers for 6 events were published ! LIGO open science center 5

When gravitational wave comes. . . 6

干渉計による検出を最初に提唱したのは誰か？ Brief early history of interferometer “ 300 years of gravitation”(1987) Cambridge University Press F. A. E. Pirani, Acta Physica Polonica 15 (1956) 389. Gedanken experiment of measurable properties of the Riemann tensor M. E. Gertsenshtein and V. I. Pustovoit Soviet Physics-JETP 16 (1962) 433. First explicit suggestion J. Weber, his lab note book (!), mid-1960’s. 8

干渉計による検出を最初に提唱したのは誰か？ Rainer Weiss, Quarterly Progress Report of Research Laboratory of Electronics of the Massachusetts Institute of Technology 105(1972)54. 　　https: //dcc. ligo. org/P 720002/public 　　　　First feasibility study　 (He also constructed interferometer) G. E. Moss, L. R. Miller, R. L. Forward, Applied Optics 10 (1971) 2495. 　 First operation result in referred paper 　　　　　　h= 2*10 -16 /Hz 1/2 First detection : h= 10 -23 /Hz 1/2 Physical Review Letters 116(2016)061102 9

Michelson干渉計で重力波を捉える Rainer Weissのアイデア Herriott, D. R. , and H. J. Schulte, Appl. Opt. 4, (1965) 883. 13

鏡を吊るす（地上の場合） Interferometric gravitational wave detector Mirrors must be free and are suspended. S. Kawamura, Classical and Quantum Gravity 27 (2010) 084001. 14

熱雑音 Thermal noise Mirrors and suspension are in heat bath. Random energy flow from heat bath Old version Limit from statistical mechanics 19

熱雑音 Thermal noise of suspension and mirror 20

地面振動 Vibration of ground shakes mirrors. Old version Seismic noise limits sensitivity below 10 Hz. Sensitivity wall in low frequency region 22

地面振動 Mirror displacement around 10 Hz must be below 10 -19 m/rt. Hz. Seismic motion around 10 Hz is 10 -11 m/rt. Hz even at Kamoka. At least 8 (in typical, 10) orders of magnitude vibration isolation is necessary ! 24

地面振動 Mirrors must be suspended because they should act as like free mass. Otherwise, transfer function from gravitational wave to detector output is too small. “Suspended” mirror is also isolated from seismic motion. 25

地面振動 Mirrors are suspended. Slow motion Mirror follows motion of support point. Rapid motion Mirror can not follow motion of support point. 26

Michelson干渉計で重力波を捉える Rainer Weissのアイデア Herriott, D. R. , and H. J. Schulte, Appl. Opt. 4, (1965) 883. 29

新しい干渉計方式 Power recycling Fabry-Perot Michelson干渉計 Resonance (Pound Drever Hall) Power recycling Ronald Drever Dark port (Shot noise) AIP Conf. Proc. 96(1983) 336. 34

新しい干渉計方式 B. J. Meers, Phys. Rev. D 38 (1998) 2317. Signal Recycling J. Mizuno et al. , Phys. Lett. A 175(1993)273. Resonant Sideband Extraction Photo detectorの前の鏡の 位置を調節することで 干渉計の重力波への 周波数応答を調節することが できる。 Power recycling ここにも鏡! 35

1990’ and 2000’ 大型干渉計型重力波検出器（第１世代）の建設と観測運転 感度は検出を期待できるものではない 4 km Arms LIGO Hanford 600 m Arms GEO 600 VIRGO 3 km Arms LIGO Livingston 4 km Arms TAMA 300 m Arms CLIO 100 m Arms 39

Bad news… Ronald Drever passed away on March 2017 … Popular information on web of Nobel foundation 41

Next step (1)Better sensitivity : Plans for 3 rd generation (10 times better sensitivity than current 2 nd generation) (2)Many other detectors in 2 nd generation for finer direction resolution KAGRA : 2 nd generation detector in Japan (Kamioka) LIGO india 42

KAGRA key feature Underground site with small seismic motion Cooled mirror and its suspension to reduce thermal noise -> 3 rd generation adopts these idea. 43

KAGRA key feature Underground site with small seismic motion Outside of mine <1 Hz (Outside of mine) =(Center of mine) >1 Hz (Outside of mine) >(Center of mine) Vertical motion is similar to horizontal one. Results of other locations are similar. K. Yamamoto, JGW-G 0500217, G 0500218 44

KAGRA key feature Underground site with small seismic motion Inside of mine > 50 m Silent sufficiently ! Main mirrors 50 m from ground K. Yamamoto, JGW-G 0500217, G 0500218 45

KAGRA timeline Phase 2 300 K Phase 1 48

KAGRA timeline O 1 O 2 O 3 LIGO, Virgo Observation Paper was accepted (PTEP) 300 K Phase 2 Phase 1 49

KAGRA timeline https: //arxiv. org/abs/1304. 0670

KAGRA timeline 感度向上の予測は むつかしいのですが…. https: //arxiv. org/abs/1304. 0670

KAGRA timeline https: //arxiv. org/abs/1304. 0670 こちらは最新の感度 Physical Review Letters 119(2017)141101.

Vibration isolation and cryostat Design drawing with tunnel and cross section 2 nd floor A. Hagiwara 14 m Shaft Clean booth Vacuum ducts along laser beam Cryostat 54

Vibration isolation and cryostat A. Hagiwara Vibration isolation system (room temperature) Cryogenic payload (Mirror is on bottom side of payload) 55

Vibration isolation and cryostat Finally, we installed this vibration isolation and cryogenic payload at one end station. A. Hagiwara Vibration isolation system (room temperature) Cryogenic payload (Mirror is on bottom side of payload) 56

Cryogenic payload Schematic view of cryo-payload Sapphire suspension Pulse tube cryocoolers Cryo-payload Sapphire fiber Sapphire mirror (About 20 K) 57

Cryogenic payload Outline of cryostat to SAS Cryogenic payload Cryostat Stainless steel t 20 mm Diameter 2. 6 m Height ~3. 6 m M ~ 10 ton Mirror View ports M Cryo-coolers Pulse tube, 60 Hz 0. 9 W at 4 K (2 nd) 36 W at 50 K (1 st) 4 Low vibration cryocooler unit ai n LA SE S. Koike R be a Remote valve unit m 58

Cryogenic payload 現在はクリーンブースが組み立てられここまで見通せない Cryostat 1. 8 m Cryo duct Cryocooler (In total, four cryocoolers) Y front cryostat

Cryogenic payload Heat link Sapphire mirror 60

Vibration isolation and cryostat Cryogenic payload A part of vibration isolation “Dummy”mirror and payload was cooled down (12 K, initial cooling time is 23 days ->no unexpected heat load !) in summer 2017. 61

Vibration isolation and cryostat Finally first cryogenic payload with sapphire mirror was installed in this week ! 62

Vibration isolation and cryostat Finally first cryogenic payload with sapphire mirror was installed in this week ! 63

Vibration isolation 大石奈緒子、天文学会(2017/9) 68

Vibration isolation 大石奈緒子、天文学会(2017/9) 70

Vibration isolation 大石奈緒子、天文学会(2017/9) 71

Vibration isolation 大石奈緒子、 天文学会(2017/9) 72

Vibration isolation 大石奈緒子、天文学会(2017/9) 73

Vibration isolation 大石奈緒子、天文学会(2017/9) 74

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 Filter 1 stage now. Type-B BS test hanging was finished. 高橋竜太郎、 Real BS installation is on going. 物理学会(2017/9) Type-Bp PR 2 & PR 3 have been installed. PRM installation is on going. BS payload with assembly frame. Installation of PR 2. Bottom filter and dummy payload 75 in Y-end.

Intensity stabilization University of Toyama 古畑貴行、強度安定化レビュー(2017/11/21)

Intensity stabilization University of Toyama 古畑貴行、強度安定化レビュー(2017/11/21)

Intensity stabilization University of Toyama 古畑貴行、強度安定化レビュー(2017/11/21)

富山大学の貢献（３） 腕のcavityとpower recycling cavityの 両方のlock(制御の 実現)は容易ではな Power い recycling Resonance (Pound Drever Hall) 缶切りが缶の 中にある （三代木） University of Toyama Dark port (Shot noise) 82

富山大学の貢献（３） Green lock 532 nmの光で一部の 光学素子を制御。 そのうえでmain laser beamで全体の制御を かけてgreen laserを off。 1064 nm University of Toyama 83

Thank you for your attention ! 87