KAGRA Cryogenic System 2017.05.19 3rd Interna1onal Mee1ng on KAGRA - PowerPoint PPT Presentation

KAGRA Cryogenic System 2017.05.19 3rd Interna1onal Mee1ng on KAGRA @Taipei Takayuki TOMARU (KEK, SOKENDAI) and the behalf of KAGRA Cryogenics Group 1

Talks by the KAGRA Cryogenics Team (1) KAGRA Cryogenic System: Takayuki Tomaru (KEK) (2) Hydroxide Catalysis Bonding (HCB) of Sapphire mirrors: Kieran Craig (ICRR, U. Tokyo) (3) Control for the KAGRA cryogenic payload: Takafumi Ushiba (ICRR, U. Tokyo) (4) EvaluaQon of 6N Aluminum Heat-Link: Tomohiro Yamada (ICRR, U. Tokyo) (5) Assembly of Prototype Sapphire Suspension: BinHua Heshe (ICRR, U. Tokyo) 2

KAGRA Cryogenics Group Nobuhiro KIMURA Kazuhiro YAMAMOTO Takafumi USHIHBA Toshikazu SUZUKI Takayuki TOMARU Cryostat sub-chief Sapphire sub-chief Cryo-Payload sub-chief Cryostat, Payload Chief KEK, Assoc. Prof. ICRR, Assist. Prof. U-Tokyo, PD KEK, Prof. KEK, Assoc. Prof. Rahul KUMAR Suguru TAKADA Helios VOCCA Kieran CRAIG Yuki Inoue Cryogenic Payload Cryogenics HCB, Perugia U, Cryogenic Payload Cryogenic Payload KEK, PD NIFS, Assist. Prof. Assist. Prof. ICRR, PD AS, PD ELore MAJORANA William CREUS 3 Payload, Univ. Roma Payload, AS, PD

Students Takahiro MIYAMOTO Hiroki TANAKA Kunihiko HASEGWA Tomohiro YAMADA Toshiro OCHI Cryo-Payload Cryo-Payload, Q Cryogenic Op1cs Cryo-Payload Cryo-Payload ICRR, D2 ICRR, D2 ICRR, D2 ICRR, M2 ICRR, D2 Total: 12 scien3sts, 6 students and 4 technicians Bin Hua HESHE Cryo-Payload ICRR, M1 Technicians Yoshikazu. NAMAI Ayako HAGIWARA Ayako UEDA Shinichi TERASHIMA Welding, KEK CAD Exp. Assistant, KEK Machining KEK, Technical Staff Technical Staff KEK, Technical Staff Technical Staff 4

Goal SensiPvity of KAGRA h ~ factor x 10 -24 [/√Hz] An issue in 2 nd genera1on GW detectors: How can we reduce thermal noises, which restrict best sensi1vity range of 100Hz. Underground Seismic Mirror Thermal Cryogenic 5 5

Cryogenic Sapphire Mirror and Suspension (1) Thermal noise � � x ( ω ) 2 ∝ T φ ReducPon φ = 5 × 10 − 9 Moreover Sapphire (bulk) φ = 1 × 10 − 7 @ 20K (fiber) Typical Φ of sapphire at room temperature is ~10 -6 will be presented by Cieran and Bin-Hua Sapphire substrate 6

(2) Thermal Lensing Fused Silica Fused Silica Sapphire Sapphire (20K) (300K) (20K) (300K) α [ppm/cm] 2 - 20 2 - 20? 40 -140 20 - 90? κ [W/m•K] 1.4 0.15 46 4.3 x 10 3 dn/dT [K -1 ] 1.4 x 10 -5 1.4 x 10 -5 1.3 x 10 -5 < |9 x 10 -8 | α (dn/dT)/κ < |0.4 - 2 x 10 -4 | 2 - 20 20 - 200 1.1 x 10 -11 Wave-front distorQon at input Wave-front distorQon at input mirror at 300K mirror at 20K ~ 10 -7 [m] ~ 10 -11 [m] Negligible 7

Cryogenic Sapphire Mirror Physics is simple But Technologies are difficult 8

Long History of Cryogenic Sapphire Mirror Development Ultra-small Vibra1on Base Technologies in KEK Cryocooler CRAB-IV GW detector Thermal Radia1on Reduc1on & Black coa1ng Superconduc1ng magnet Heat Conductor -> Yamada’s Talk for accelerators 9

Cryogenic Mirror Suspension Main mirror parts r o o l F r e p p Frame-Free Suspension U We excavate upper-floors Type-A: Takahasi’s talk and verQcal holes for Type-A suspension: VibraQon IsolaQon System. 4-stage GAS filters Base of the VIS is put 14m @ room temperature on the upper-floor Boiom Floor Arm tunnel Cryogenic Payload 10

Cryostat & Cryogenic Payload Cryostat Type-A PlaAorm MarioneCe & Recoil mass Intermediate mass & recoil mass Mirror & Recoil mass 11

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Performance Test of KAGRA Cryostats 13

Cooling Test Result of X-end Cryostat (2017.Feb.6~Mar.13） Feb. 6 OperaPon start Toshiba KAGRA site Ini3al cooling 3me is comparable with that at factory test in Toshiba.

Cooling Test Result of X-end Cryostat ~82 K at the top of the 80 K outer shield 13.2 K at the side of 8 K inner shield ４７ ~5 ６ K @ 1 st cold stage 6.1 & 6.8 K of Cryo-cooler @ cryo payload system 12.5 K @ 3.9 & 5.7 K 10 & 12 K shield sysytem @ cryo payload @ 8 K shield system 15

VibraPon Measurement Result in X-front Cryostat Large vibraQon was found btw 10 and 100Hz region. These vibraQons look to correspond to structural resonance of cryostat. But sQll under invesQgaQon. 1.0E-05 Kamioka_cryocooler on 神岡 _ 冷凍機 on 1.0E-06 Toshiba_cryocooler on VibraQon displacement(m/rtHz) 東芝 _ 冷凍機 on 1.0E-07 1.0E-08 1.0E-09 1.0E-10 Collaborated by Roma Univ. 1.0E-11 1.0E-12 1 10 100 frequency （ Hz ） 16

Cryogenic Payload Done Plaform Readiness Heat Link Done • 6N stranded: done • 5N bars: soon MarioneLe None-magnePsm Done black coaPng • June-Aug. Intermediate Mass Actuator & Sensor ~80% • under fabricaQon Mirror Recoil Done Model in Digital System ~60% -> Miyamamoto Sapphire Suspension Done InstallaPon Jigs • Yend: done Frame (Earthquake Stop) • Xend: June-July Done 17

Assembly and InstallaPon Test at X-end Cryostat Slide rail Crane Cart OpQcal Bench Assembly space 18

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We learned many improvement points • Add more scratch marking for alignment • Fabricate electrical cable cramps • Add spring washers • Fabricate cramps on the frame • Check screw length • Fabricate a new mirror box • Improve the screws for linear guides • Fabricate a new spacer to fix mirror box • Improve the jig for alignment guide of on XYZ stage for assembly sapphire blade springs • Add locking bolts on XY stages • Add the caps of micrometer for sapphire • Improve design of mirror actuator mount blade springs • Improve spacing of mirror recoil cap • Add screw caps for earthquake stops • Fabricate mirror recoil cap holder/installer • Improve earthquake stop design for • Fabricate cooling bar in the cryostat mirror recoil mass • Finalize fiber installer design • Add verQcal earthquake stops • Wrong suspension rod length • Minor improvement of wire tensioner design • Need more installaQon training • Change the height of OpLev mirror at MT • Need more laser line markers 21

We have already started Cryo-Payload Improvements Example: Improve Design of Mirror Actuator Mount 22

Major Schedule in this FY ETMX: End Test Mass, X ETMY: End Test Mass, Y • Early July: Test installaQon of cryo-payload with sapphire suspension at the X-end cryostat • July-Sept.: Cool-down test of X-end cryostat with cryo-payload • End Aug.: ETMY HCB starts • Mid. Sept.: ETMY strength test complete. ETMY installaQon into cryo-payload starts • End Sept.: Cryo-Paylaod InstallaQon into Y-end cryostat complete. • End Sept.: ETMX HCB starts • Mid. Oct.: ETMX HCB strength test complete ETMX installaQon into cryo-payload starts • Oct.-Nov.: Interferometer commissioning at room temp. • Early Dec.: Start cooling down of ETMX and ETMY • Feb.-Mar.: bKAGRA-1 test operaQon 23

Next Year 24

Back Up 25

Layout of Cryostats Ultra high vacuum beam tube 100K cryogenic tube for thermal radiaQon shielding (Duct Shield) 3 km Ultra-small vibraQon cryocooler system (100K) Ultra-small vibraQon cryocooler system (4K) Cryostat Laser BS 3 km 26

Ultra-small vibraPon cryocooler system This technology was established in CLIO prototype interferometer • nm vibraPon at cold stage • comparable vibraQon level of whole system with Kamioka seismic vibraQon Commercial Pulse-Tube Cryocooler Whole System -2 -5 Cold Stage 10 10 VRS Lower Stage -3 10 VRS Upper Flange Commercial 1/2 ] Original PT -4 1/2 ] 10 -6 10 Kamioka Seismic Displacement Density [m/Hz Pulse-Tube Cryocooler Displacement Density [m/Hz -5 10 3 order -6 10 -7 10 -7 10 -8 Also, vibraQon test of a “cryostat” will be performed in this month 10 -8 10 -9 10 2 order in the collaboraQon work with Rome University on the basis of -10 10 -9 10 -11 10 Our system Our system ELiTES program. -12 10 -10 10 -13 10 0.1 1 10 100 0.1 1 10 100 27 Frequency [Hz] Frequency [Hz]

ReducPon of thermal radiaPon To realize conducQon cooling by using small cryocoolers, heat load in cryostat must be below several wai. But GW interferometer can not have opQcal windows on leaser beam path, Black coaQng so large heat load from the openings exists. We succeeded to reduce about 1/1000 Qmes thermal radiaQon heat load from beam openings by using 100K cold tubes with black coaQng and baffles. Cryostat Black coaPng and baffles in cold tube 28

Cooling down test of the Y-end cryostat (PreparaPon) 29

16.11.8 300 '4KRef50KConductor' '4KRef50KHead' '4KRef4KConductor' '4KRef4KHead' '80Kbottom' '80Kside' '4KbarPay' '4KbarShield' '4Kside' Date 16.11.6 '50KRefHead' 16.11.4 16.11.2 16.10.31 16.10.29 16.10.27 '50KRefConductor' 50 100 150 200 250 'DuctShield (CryoSide)' Cooling down test of the Y-end cryostat Temperature [K] 30

2. PreparaPon Status of Cryogenic Payloads 31

Readiness Plaform Frame (Earthquake Stop) • Under fabricaQon ~70% • Designing Heat Link MarioneLe • Test fabricaQon done • One fabricated by using 6N Al wires • Three under fabricaQon None-magnePsm Intermediate Mass black coaPng ~70% • One fabricated • TesQng • Three under fabricaQon Actuator & Sensor ~40% • SimulaQon & test Mirror Recoil Model in Digital System • One fabricated ~30% • Three under • SimulaQon & test fabricaQon InstallaPon Jigs ~30% Sapphire Suspension • Designing -> K. Craig 32