1. 2012.07.31 Collaboration Meeting
KAGRA Cryogenics
Status of Cooling system by T.Suzuki
and
Cryogenic payload by K.Yamamoto
Collaboration Meeting

2. Cryostat Assembling in progress
Some low quality of handling was found in the first set of radiation shields. Improvement has been required.
Cryochambers
8K Radiation shields
80K Radiation shields

3. Cryostat Performance test is scheduled from the October.
Leak rate < 1 x Pa m3/sec
Pressure < 10-7 Pa ( after cooling down )
Cooling capacity
Heat load on payload cooling paths
Heat load on the 8K shield wall
Vibration on the 8K shield (2nd test)
Interferometer (ICRR), accelerometer (Roma Univ.)

4. Cryostat Passage test with a mockup model agreed to Kashima.
Start to prepare the mockup model and jigs
Test schedule
Installation
Haulage in the tunnel : synchronize with vacuum chambers.
Consistent installation flow with type-A
2.65 m
4 m
3.05 m
4 m

5. 4K cryocooler unit In 2012FY, nine units are manufactured.
Apr. ~ July : Procurement of parts
End of July ~ Feb : Assembling and performance test in succession.
Measurement of 4K PTC (SHI)
Cooling capacity
Vibration of cold stage (bare)
An example of vibration
Y.Sakakibara
Target position

6. Shield Duct Design in progress Manufacturing schedule will be behind
Supply of vacuum duct and bellows will be available in Mar
Lack of third single stage PTC
Solvay cryocooler is under study as an alternative