Cryogenic Payload Issues K. Yamamoto 2015 December 2 4th ELiTES meeting @Ookayama campus, Tokyo Institute of Technology, Mugero-ku, Tokyo, Japan 1 1 1 1

0. Abstract Here, I explain Cryostat installation at KAGRA site Cryogenic payload Sapphire suspension Details will be presented by researchers in Japan. 2

Cryostat installation Cryogenic payload Sapphire suspension Summary Contents Introduction Cryostat installation Cryogenic payload Sapphire suspension Summary 3

1. Introduction Schematic view of KAGRA interferometer Four mirrors of arm cavity will be cooled. 3km 3km Mozumi Y-end Sakonishi X-end Kamioka mine (Underground site) Atotsu Center Vibration isolation system (Type A), Cryocooler unit, Cryostat, Cryogenic payload 4 4 4 4 4 4 4 4

Vibration isolation system Vacuum ducts along laser beam 1. Introduction Outline of vibration isolation and cryostat Design drawing with tunnel and cross section 2nd floor A. Hagiwara Vibration isolation system (room temperature) 14 m Shaft Clean booth Vacuum ducts along laser beam Cryostat (Here is a mirror) 5 5 5

1. Introduction Schematic view of cryo-payload Sapphire suspension Pulse tube cryocoolers Pulse tube cryocoolers Sapphire fiber Cryo-payload Sapphire mirror (About 20K)

1. Introduction Schematic view of cryo-payload Pulse tube cryocoolers Cryo duct for 300 K radiation

2. Cryostat installation Status of one year ago (T. Suzuki’s talk in last ELiTES meeting) http://events.ego-gw.it/indico/getFile.py/access?contribId=8&sessionId=2&resId=0&materialId=slides&confId=16 Two cryostats have already been installed. Leak test and survey were in progress.

2. Cryostat installation What happened after last ELiTES meeting ? R. Kumar (T. Suzuki) explains in this session (tomorrow afternoon). Last two cryostats were installed. Cryo ducts are connected to two cryostats in the center room. Leak test and survey are in progress.

2. Cryostat installation Geophysics There is an interferometer for geophysics at KAGRA site. (Optical components are fixed on ground, not suspended) Installation was finished and commissioning is started. K. Miyo presents tomorrow afternoon. 40cm Retro Reflector

2. Cryostat installation Water is serious problem even now … But could be an issue in operation ? For example, gravity gradient noise ? K. Somiya presents tomorrow afternoon.

3. Cryogenic payload Outline of vibration isolation and cryostat Pulse tube cryocoolers Pulse tube cryocoolers Cryo-payload 12 12 12 12 12 12 12

3. Cryogenic payload Outline of cryogenic payload Mirror chain Platform Recoil mass chain Marionette Intermediate mass Thermal noise caused by recoil mass chain is small. Sapphire Mirror http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=2106 13 13 13 13 13 13 13

3. Cryogenic payload Outline of cryogenic payload GAS filer Platform for vertical vibration isolation (Mirror chain is suspended) Platform Marionette Intermediate mass Sapphire Mirror 14 14 14 14 14 14 14

3. Cryogenic payload Outline of cryogenic payload Platform Alignment adjustment system Platform Marionette Simple system for high Q-value of sapphire suspension Intermediate mass Sapphire Mirror 15 15 15 15 15 15 15

3. Cryogenic payload Outline of cryogenic payload Platform Sensor and actuator (for control and damping) Marionette Intermediate mass Sapphire Mirror 16 16 16 16 16 16 16

3. Cryogenic payload Design A. Hagiwara proceeds with Without recoil chain Design A. Hagiwara proceeds with CAD design drawings. Almost all parts except for platform were designed. Design is based on discussion with Vibration Isolation subgroup of KAGRA. Marionette Platform Intermediate mass Mirror A. Hagiwara 17 17

3. Cryogenic payload Design A. Hagiwara proceeds with With recoil chain Design A. Hagiwara proceeds with CAD design drawings. Almost all parts except for platform were designed. Recoil mass for Marionette Recoil mass for intermediate mass Recoil mass for mirror A. Hagiwara 18 18

3. Cryogenic payload Prototype test of cryogenic payload Two differences from actual one Platform does NOT include GAS filter. Mirror and fibers are NOT made from sapphire, but metal. 19

3. Cryogenic payload Prototype test of cryogenic payload Without recoil chain Prototype test of cryogenic payload Marionette, Intermediate mass, Dummy mirror, Recoil mass for dummy mirror has already been delivered. Marionette Intermediate mass Dummy Mirror (and recoil mass) A. Hagiwara 20 20

3. Cryogenic payload 23 kg 150 mm 220 mm Prototype test of cryogenic payload Dummy mirror and ears (stainless) Size and weight are the same as those of KAGRA mirror. 23 kg 150 mm 220 mm Ears (stainless) Recoil mass 21 21 21 21 21 21 21

3. Cryogenic payload Prototype test of cryogenic payload (VIC international) Dummy blade spring Marionette Intermediate mass 22 22 22 22 22 22 22

3. Cryogenic payload Prototype test of cryogenic payload T. Miyamoto assembled ! He is developing (1) alignment adjustment system of Marionette (2) displacement sensor for control and damping (3) coil magnet actuator for sapphire mirror They should work around 20 K. 23

3. Cryogenic payload Prototype test of cryogenic payload T. Miyamoto conducts cooling test on December. Details of design and this prototype will be explained by R. Kumar in this session. 24

3. Cryogenic payload Schedule Procurement for KAGRA cryogenic payload First one will be delivered by March 2016. Other ones will be delivered by March 2017. ETM and ITM will be delivered by September 2016 and March 2017, respectively. Installation will be in second half of 2017. 25

4. Sapphire suspension Sapphire lop-eared suspension “Sapphire monolithic lop-eared suspension” One of the most important parts of KAGRA : Main sapphire mirrors are included. All parts are made from sapphire. fiber break Hydroxide Catalysis Bonding 26

4. Sapphire suspension Blade spring Fiber with nail head on both ends Sapphire lop-eared suspension Blade spring (compensation of fiber length difference) Fiber with nail head on both ends Flat cut Nail head of fiber Mirror Ear A. Hagiwara

4. Sapphire suspension Sapphire lop-eared suspension When fibers are broken, they can be removed ! Hydroxide Catalysis Bonding

4. Sapphire suspension Sapphire lop-eared suspension How to make sapphire fiber with nail head ? (1)Drilling (2)Bonding We adopt (2) because the diameter of thin part in (1) is large for KAGRA. Nail head itself should be small (thermal noise).　　　　　　　　 Drilled Bonding Bonding 29

4. Sapphire suspension Current status We investigated almost all components. Measurement of Q-values of sapphire fiber is still in progress. We are preparing to construct full size suspension (as prototype). R. Kumar explains in this session. Simpler (one fiber) prototype test is in progress. K. Craig presents in this session. 30

4. Sapphire suspension Full size suspension as prototype Assembly (thick four fibers, exactly challenge) Measurement of mechanical response (resonant frequencies) Cooling and heat load test Measurement of Q-values 31

4. Sapphire suspension Full size suspension as prototype All sapphire parts for full size prototype have already been delivered (IMPEX and Shinkosha). Sapphire cylinder with flat cuts as dummy mirror Fibers with nail head Blade spring Ears 32 32 32 32 32 32 32 32

4. Sapphire suspension Full size suspension as prototype Jigs to assemble full size prototype is being prepared(R. Kumar, K. Craig). Some parts were delivered. 33 33 33 33 33 33 33 33

4. Sapphire suspension Full size suspension as prototype Hydroxide Catalysis Bonding Jig and dummy bulk were prepared (K. Yamamoto). 34 34 34 34 34 34 34 34

4. Sapphire suspension Full size suspension as prototype Measurement of shape of sapphire bulk and ears For precise position of ears, the geometrical shape and ears were measured (by K. Enami, Mechanical Engineering Center, KEK). 35 35 35

4. Sapphire suspension One fiber prototype Simpler prototype (easier assembly) Short cooling time Sapphire blade spring Sapphire fiber 145.3mm 6kg sapphire mass (1/4 of KAGRA mirror) 145.3mm D. Chen 67.5mm 36 36 36 36 36 36 36 36

4. Sapphire suspension One fiber prototype Simpler prototype (easier assembly) Indium bonding, Mechanical response, Cooling and heat load test, Thermal cycle test, Measurement of Q-values,… H. Tanaka proceeds with experiment. K. Craig presents in this session. 37 37 37 37 37 37 37 37

4. Sapphire suspension One fiber prototype 6kg mass (copper) (1/4 of KAGRA mirror) Sapphire blade spring Nail head of sapphire fiber Support frame 38

4. Sapphire suspension One fiber prototype Sapphire blade spring Dummy Cu wire Sapphire mass D. Chen, J. Komma, H. Tanaka, Y. Liu

4. Sapphire suspension Schedule Procurement for KAGRA sapphire suspension: Eight fibers and four ears (by March 2016) Eight fibers and four ears (by March 2017) ETM and ITM will be delivered by September 2016 and March 2017, respectively. Installation will be in second half of 2017. 40

4. Sapphire suspension T. Tomaru and K. Yamamoto joined assembly fused silica suspension of AdVirgo (23rd-27th of November). 41

4. Sapphire suspension T. Tomaru and K. Yamamoto learned a lot of thing and appreciate their (especially, E. Majorana’s) kindness. ELiTES stimulates such missions. 42

4. Sapphire suspension Mechanical loss of coating Thermal noise is dominated by this loss. Discrepancy between Tokyo and Glasgow Tokyo No peak No annealing effect Glasgow Peak around 20 K Annealing suppresses peak. I.W. Martin et al., Classical and Quantum Gravity 27 (2010) 225020. K. Yamamoto et al., Physical Review D 74 (2006) 022002. 43 43 43

4. Sapphire suspension Mechanical loss of coating Measurement at ICRR was repeated with Glasgow group. Again, no peaks and annealing effect ! E. Hirose et al., Physical Review D 90(2014) 102004.

4. Sapphire suspension Mechanical loss of coating LMA provided coating on sapphire disk. Loss of the same coating was measured by Glasgow and LMA. First chance of cross check with same coating J. Katayama presents this afternoon. M. Granata et al., Opt. Lett. 38, 5268 (2013)

4. Sapphire suspension After sucess of reduction of thermal noise, quantum noise must be an issue. K. Nagano explaines quantum experiment with small mirror tomorrow afternoon.

5. Summary Cryostat installation All four cryostats were installed ! Connection to cryo duct, survey, leak test are in progress. Cryogenic payload Almost all parts except for platform were designed. Parts of mirror chain were assembled. System to adjust or control cryogenic payload are being developed. Cooling test will be started soon ! 47

5. Summary Sapphire lop-eared suspension Assembly jig for full size prototype are being prepared. One fiber prototype experiment is in progress. Measurement of LMA coating mechanical loss will be started soon. 48

Acknowledgement Supported by Mechanical Engineering Center, KEK Machine shop, The Institute for Solid State Physics, The University of Tokyo 49 49 49

Thank you for your attention ! 50

Backup 51

6. Summary Next step (by Spring 2016) Full size prototype at KEK and ICRR 2. By Spring 2017 Development of platform (GAS filter) By Summer 2017 Assembly and test of sapphire suspension In the second half of 2017 Installation at KAGRA site One postdoc joins one week later. KAGRA must take care of KEK people. Otherwise, they can not work for KAGRA after 2018. 52

3. Sapphire suspension Schedule By Spring 2016 : Prototype test of full size sapphire suspension at ICRR By Autumn 2016 : Procurement of sapphire parts By Spring 2017 : Assembly and test with End sapphire mirrors By Summer 2017 : Assembly and test with Front sapphire mirrors By End 2017 : Installation at KAGRA site 53

3. Cryogenic payload Schedule By Spring 2016 : Prototype test of full size prototype at KEK By Spring 2017 : Development of platform (GAS filter) By End 2017 : Installation at KAGRA site 54

4. Schedule 55

4. Schedule Full size prototype at KEK and ICRR Procurement of sapphire parts Assembly and test of sapphire part Development of platform (GAS filter) Installation of cryogenic payload 56

4. Schedule Cooling test of cryostat Installation of Type A Delivery of End sapphire mirrors Delivery of Front sapphire mirrors Installation of cryogenic payload 57 57 57

Extremely short commissioning 5. Schedule Official schedule iKAGRA observation : By end of 2015 bKAGRA installation and commissioning : By end of 2017 Current budget plan By March 2016 : One cryogenic payloads By March 2017 : Three cryogenic payloads (+ spare) By end of 2017 : Commissioning of bKAGRA Extremely short commissioning 59

60

3. Cryogenic payload Outline of cryostat Cryogenic payload Mirror to SAS Cryogenic payload Cryostat Stainless steel t20mm Diameter 2.6m Height ~3.6m M ~ 10 ton Mirror View ports 4 Low vibration cryocooler unit Cryo-coolers Pulse tube, 60Hz 0.9 W at 4K (2nd) 36 W at 50K (1st) Main LASER beam Remote valve unit S. Koike

3. Cryogenic payload Outline of vibration isolation and cryostat Heat link (pure Al) Heat link (pure Al) Pulse tube cryocoolers Pulse tube cryocoolers Cryo-payload 62 62 62 62 62 62 62

3. Sapphire suspension Measurement of Q-values of sapphire fiber Q-value of 350 mm length fiber for KAGRA is not measured yet. Short (100mm) fiber measurement suggests clamp for fiber brings loss and reduce measured Q-values. Next talk (H. Tanaka) Probably not necessasry 63