Reduction of Observation Deadtime of Gravitational wave Telescope KAGRA

2017 Fiscal Year Final Research Report

• Project/Area Number: 26287052
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: High Energy Accelerator Research Organization
• Principal Investigator: Tomaru Takayuki 大学共同利用機関法人高エネルギー加速器研究機構, 超伝導低温工学センター, 准教授 (80391712)
• Co-Investigator(Renkei-kenkyūsha): SUZUKI Toshikazu 高エネルギー加速器研究機構, 超伝導低温工学センター, 教授 (20162977) ; KIMURA Nobuhiro 高エネルギー加速器研究機構, 超伝導低温工学センター, 准教授 (10249899) ; SAITO Yoshio 高エネルギー加速器研究機構, 加速器研究施設, 教授 (00141979) ; TAKADA Suguru 核融合科学研究所, ヘリカル研究部, 助教 (30578109)
• Research Collaborator: HASEGAWA Kunihiko 東京大学, 大学院理学系研究科
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: 重力波 / 極低温 / 超高真空

Outline of Final Research Achievements

Cryogenic interferometric gravitational wave detector, which is developed by Japan, has the unique issue of mirror contamination by cryogenic pump effect. Due to this issue, KAGRA gravitational wave telescope in Japan needs maintenance term for two months in every year. This observation dead time is pretty large issue for KAGRA since a main target of gravitational wave detection is sudden astronomical events, and we need to reduce such observation dead time. In this research, we re-evaluated the contamination mechanism of mirror due to cryogenic pump effect by experiment. We concluded that the main component of mirror contamination is remaining water molecules in vacuum and its speed of growth on mirror was 26.8nm/day. And We successfully reduced cooling and warming up time to be half by the development of high performance thermal conductor and an improvement of warming up method.

Free Research Field

宇宙物理学実験