Current status. Kazuhiro Yamamoto Institute for Cosmic Ray Research The university of Tokyo. KAGRA(LCGT) cryogenic payload meeting 8 February 2012. There are a lot of meetings in the recent one month. AOS meeting(13th of Jan.). T. Akutsu pointed out that
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Institute for Cosmic Ray Research
The university of Tokyo
KAGRA(LCGT) cryogenic payload meeting
8 February 2012
T. Akutsu pointed out that
(a)the baffles for scattered light might be installed in cryostat.
Where are they put ?
How are they suspend for vibration isolation ?
How the heat by the light absorption is extracted ?
(b)there is the possibility that duct shield
might be the problem of the scattered light.
We discussed, but it is not so easy to find the solutions …
(a)Rough evaluation of the noise by scattered light (Akutsu)
(b)Temperature of inner shield with 4 W heat load (Kimura)
The answer is 12.3 K.
(c) Magnitude of large angle scattered light measured in LIGO
The answer is 10 ppm (H. Yamamoto).
(d) Simulation of vibration of shield (Tokoku)
Discussion with Mike Smith : Today, after this meeting
Next meeting : 15th of Feb. (Wed) 10:30-
ICRR, TV conference room
EVO (LCGT AOS CRYOGENIC PAYLOAD)
(b)Investigation of the light scattered by the edge of baffles in duct shield
(c)Quality check plan for sapphire fibers
(d)Vibration of radiation shields (scattered light)
Items for main interferometer : Calculation for hierarchy control
Deadline of document of external review : 17th of March
External review : 17th-20th of April
Reoprt of sub groups : 3rd of Feb.
Warren Johnson and Riccardo DeSalvo join cryogenic payload mailing list.
New KAGRA collaborator
SICCAS‐GCL Crystal Research & Development Center
They can process (cut and so on) sapphire bulk.
K. Yamamoto will discuss this issue with Lihe Zheng and Jingya Wang in this week.
Prof. Mio : a-axis sapphire (25cm in diameter, 15cm in thickness) will arrive soon. It can be used as mirror for 1/4 cryostat experiment.