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Sapphire mirror for the KAGRA gravitational wave detector

Hirose, Eiichi and Bajuk, Dan and Billingsley, Garilynn and Kajita, Takaaki and Kestner, Bob and Mio, Norikatsu and Ohashi, Masatake and Reichman, Bill and Yamamoto, Hiroaki and Zhang, Liyuan (2014) Sapphire mirror for the KAGRA gravitational wave detector. Physical Review D, 89 (6). Art. No. 062003. ISSN 2470-0010. doi:10.1103/PhysRevD.89.062003.

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KAGRA, the Japanese interferometric gravitational wave detector currently under construction, will employ sapphire test masses for its cryogenic operation. Sapphire has an advantage in its higher thermal conductivity near the operating temperature 20 K compared to fused silica used in other gravitational wave detectors, but there are some uncertain properties for the application such as hardness, optical absorption, and birefringence. We introduce an optical design of the test masses and our recent R&D results to address the above properties. Test polish of sapphire substrate has especially proven that specifications on the surface are sufficiently met. Recent measurements of absorption and inhomogeneity of the refractive index of the sapphire substrate indicate that the other properties are also acceptable to use sapphire crystal as test masses.

Item Type:Article
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URLURL TypeDescription DOIArticle
Billingsley, Garilynn0000-0002-4141-2744
Zhang, Liyuan0000-0002-0898-787X
Additional Information:© 2014 American Physical Society. Published 24 March 2014; Received 3 February 2014. We are grateful for financial support from the Leading-edge Research Infrastructure Program funded by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) in Japan. The LIGO Observatories were constructed by the California Institute of Technology and Massachusetts Institute of Technology with funding from the NSF under cooperative agreement No. PHY- 9210038. The LIGO Laboratory operates under cooperative agreement No. PHY-0328418. We thank our colleagues in both the KAGRA Collaboration and the LIGO Scientific Collaboration (LSC). This paper has document numbers JGW-P1302017 and LIGO-P1400005.
Funding AgencyGrant Number
Leading-edge Research Infrastructure ProgramUNSPECIFIED
Ministry of Education, Culture, Sports, Science and Technology (MEXT)UNSPECIFIED
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Other Numbering System NameOther Numbering System ID
LIGO DocumentLIGO-P1400005
Issue or Number:6
Classification Code:PACS: 04.80.Nn, 95.55.Ym
Record Number:CaltechAUTHORS:20140528-111642578
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Official Citation:Hirose, E., Bajuk, D., Billingsley, G., Kajita, T., Kestner, B., Mio, N., . . . Zhang, L. (2014). Sapphire mirror for the KAGRA gravitational wave detector. Physical Review D, 89(6), 062003.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:45938
Deposited On:28 May 2014 22:27
Last Modified:10 Nov 2021 17:18

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