27/Aug./2015 KAGRA f2f meeting N. KIMURA High Energy Accelerator Research Organization, KEK Progress status of Cryogenic System at KAGRA site

27/Aug./2015 KAGRA f2f meeting

N. KIMURAHigh Energy Accelerator Research Organization, KEK

Progress status of Cryogenic Progress status of Cryogenic System System

at KAGRA siteat KAGRA site

27/Aug./2015 KAGRA f2f meeting2

Outline

Over View of KAGRA Cryogenics

Components of the Cryogenics

Construction of Cryostat

Proposed Work Schedule

Summary

3 333

14 m

Vacuum ducts along laser beam

Vibration isolation system(room

temperature)

Clean booth

Design drawing with tunnel and cross section

Cryostat(Here is a mirror)

2nd floor

Shaft

A. Hagiwara

Structure of vibration isolation and cryostat

Progress status of assembling the cryostats;

•EXC & EYC were assembled as vacuum vessels

without duct shields and cryo-coolers

from the end of 2014.11 to the end of 2015.1.

•IYC & IXC were assembled with all of components

such as duct shields and cryo-cooler units

from the end of 2015.2 to the mid of 2015.4.

EYC

EXCIXC

IYC

• Duct Shield

• 12 mL vacuum duct

• 6 mL +6 mL vacuum

duct

• Cryostat

• Gate Valve

BS

3 km

3 km

Cryo-cooler unit installation

BS

3 km

3 km

IXC

IYC

EYC

EXC

View of Assembled Cryostats

Reached pressurein the Y-front cryostat3.7x10-7 kPa


X&Y-end cryostats •Leak test were cleared based on KAGRA requirement

< 1x10-10 Pa*m3/sec•No excess leak found above the background

(~1x10-12 Pa*m3/sec)

X&Y-front cryostats•At leak test,

two small leak spots < 1x10-9 Pa*m3/sec were founded by the reason of malfunction of gaskets.•It should be replace until mid of September 2015.

Leak test


Proposed Proposed Future Plans of KAGRA Future Plans of KAGRA CryogenicsCryogenics

2015 2016

Jan./’16

We are hereJuly, 23rd

Re-align position of EXC&EYC,and connect cross tube between cryostat and vacuum vessel for VIS.

Operation of iKAGRA

Connect cryo-coolers and duct shields to EXC&EYC

Performance test with confirming vibrationin the cryostat

Connect compressors, flexible horse and cables to cryostat

Jan./’17June/’16 June/’17

up grade work to bKAGRA

Apr./’16~May/’16

June/’16~July/’16

Aug./’16~Oct./’16

We have already proposed above schedule to SEO.We would like to complete KAGRA cryogenic system for next year.


SummarySummary

8

• Completed assembling X&Y-end cryostats without cryo-

coolers

and cleared leak tests based on KAGRA requirement

• Completed assembling X&Y-front cryostat including

connection of 11 cryo-cooler units and 4 duct shields.

• At leak test of the front,

two small leak spots < 1x10-9 Pa*m3/sec were founded

by the reason of malfunction of gaskets.

• It should be replace until mid of September 2015.

• A plan for connection of cryo-cooler units and duct shields at

X&Y-end cryostat were proposed and accepted by SEO.

It should be launched at mid of March 2016.

9

KAGRA Cryogenics Group

Toshikazu SUZUKI EO and SEO member KEK, Senior Fellow

Nobuhiro KIMURA Cryostat sub-chief KEK, Assoc. Prof.

Kazuhiro YAMAMOTO Cryo-Payload sub-chief ICRR, Project Assist. Prof.

Takayuki TOMARU Chief KEK, Assoc. Prof.

Tatsuya KUME Surveying, Alignment KEK, Assoc. Prof.

Rahul KUMAR Simulation, Payload KEK, PD

Ayako HAGIWARA CAD KEK, Technical Staff

Shinichi TERASHIMA Machining KEK, Technical Staff

Iwao MURAKAMI Welding, Assembly KEK, Technical Staff

Hiroki TANAKA Cryo-Payload, Q ICRR, Grad. Student

Takahiro MIYAMOTO Cryo-Payload ICRR, Grad. Student

Suguru TAKADA Cryogenics NIFS, Assist. Prof.

2015.Jul.25

By T. Tomaru(Revised by K. Yamamoto)


Conceptual Design Conceptual Design of the Cryogenicsof the Cryogenics

Four 4K cryocooler units per one cryostat Baffles against wide scattering is cooled via 8K shield.

Main Beam

Cooling 8K shield

Cooling Cryo-Payload

Duct Shield

400kW4W?

~1W

Cryostat80K shield

8K shield

two units

80K PTC withVibration reduction

4K PTC withVibration reduction

two units

2 units for cool cryo-payload2 units cool for 8K shield4 units cool for 80K shield

Low vibration in U. H. VacuumStop propagation of 300K radiationPrevent heating by scattered beam

300K Radiation

Baffles


Gate valve Gate valve

Connection Port to SASMirror a cryostat

Location of Four Mirror Cryostats in Kamioka MineConstructed at the position of 1 km in depth.

Mozumi-End Atotsu-End

X-Front RoomY-Front Room

L=5 m

L=5 m

Vacuum duct800 with radiation shield

Vacuum duct800 with radiation shield


Structure of KAGRA CryostatStructure of KAGRA Cryostat

Seismic Attenuation System (SAS)

Duct Shield

Four Cryocooler Units

Main Laser Beam

Radia

tion S

hie

lds

4.3

m

2.6m

Cryogenic Payload

Sapphire Mirror(-alumina crystal)

S.Koike

View Ports

Stainless steel t=20mmDiameter 2.4 mHeight ~4.3 mM ~ 12 tonCold Mass:8K shield ~455 kg80 K shield ~590 kg

CryocoolersPulse tube, 60Hz0.9 W at 4K (2nd)36 W at 50K (1st)


Recommendation 18: The basic performance test/inspection, especially leak tests, should be completed before the beam tube installation. The current plan to do this by the coming January should be kept. Suzuki: The leak test of Cryostat in X-end was performed in January 2015. The top flange of the cryostat with a diameter of 2400 mm was fastened using a metal gasket. This part will never be able to open after constructing a clean booth. No excess leak was found on the background level of 1x10^-12 Pa*m^3 /sec. This result satisfied the requirement of KAGRA vacuum system that specify a leak less than 1x10^-10 Pa*m^3 /sec. Assembling other three cryostats in Y-end and XY-front is in progress. Leak test for those cryostats will finish until April 2015.

Recommendation: Vibration measurements with the cryo-cooler in operation should be repeated at appropriate locations corresponding to the final design configuration, to more accurately assess vibration transfer. If the resulting spectrum remains as serious as was presented from the preliminary measurements shown, more understanding anddevelopment of mitigation techniques will be necessary. This may have radical impact on the cryogenic plant and/or payload designs.Comment: All the cryocoolers have been delivered to the KAGRA site, but cryocoolers have not all been integrated with the end cryostats. Although the cooling time for the radiation shield and vibration levels at the shield have been measured at Toshiba facility, it is highly desirable to demonstrate the cooling and vibration levels inside the realcryostat at the KAGRA site as soon as possible to alleviate remaining uncertainties about the cryogenic operation of KAGRA. If isolation of cryocooler vibration should be insufficient, it could render the vibration isolation achieved by super-attenuators useless.Recommendation: The cryocoolers should be integrated with at least one end cryostat and vibration isolation system, so that both cooling and vibration isolation can be tested as soon as possible. This will also afford VIS and CRY teams an opportunity to work together on integration of their systems.

2014 PAB

2015 External Review

Documents

27/Aug./2015 KAGRA f2f meeting N. KIMURA High Energy Accelerator Research Organization, KEK Progress status of Cryogenic System at KAGRA site