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2001 Fiscal Year Final Research Report Summary

Development of cryogenic mirrors for interferometric gravitational wave detectors

Research Project

Project/Area Number 10304017
Research Category

Grant-in-Aid for Scientific Research (A)

Allocation TypeSingle-year Grants
Section一般
Research Field 素粒子・核・宇宙線
Research InstitutionThe University of Tokyo

Principal Investigator

KURODA Kazuaki  Institution for Cosmic Ray Research, The University of Tokyo, Professor, 宇宙線研究所, 教授 (00242165)

Co-Investigator(Kenkyū-buntansha) YAMAMOTO Akira  High Energy Accelerator Research Organization, Cryogenics Science Center, Professor, 低温工学センター, 教授 (30113418)
SHINTOMI Takakazu  High Energy Accelerator Research Organization, Cryogenics Science Center, Professor, 低温工学センター, 教授 (10016082)
OHASHI Masatake  Institution for Cosmic Ray Research, The University of Tokyo, Associate professor, 宇宙線研究所, 助教授 (80213833)
TSUBONO Kimio  Department of Physics, The University of Tokyo, Professor, 大学院・理学系研究科, 教授 (10125271)
MIO Norikatsu  Department of Applied Physics, The University of Tokyo, Associate professor, 大学院・新領域創成科学研究科, 助教授 (70209724)
Project Period (FY) 1998 – 2001
KeywordsGravitational Wave / General Relativity / Cryogenic mirror / Sapphire mirror / Sapphire fiber / Thermal noise / Fabry-Perot Interferometer / High-sensitive laser interferometer
Research Abstract

The detection of gravitational wave proves the existence of the wave itself and makes possible the astronomical observation of the dynamics, distributions and distances of gravitational sources such as compact stars. It also makes possible to test the theories of gravitation. Accordingly, the detection of the wave would bring epoch making knowledge to both physics and astronomy. In this research program, we conducted a research on the development of a cryogenic mirror and on the reduction of thermal noise using this technique for the aim of development of a more sensitive cryogenic laser interferometer for gravitational wave detection. If the temperature of the mirror reduces from 300K to 30K, the amplitude of its thermal noise decreases down to one third in the first approximation. In reality, one order improvement can be expected due to the increase of mechanical quality factor of vibration at cryogenic temperature. Since the mirror is suspended by thin fibers in ultra-high vacuum, t … More here is no other way to cool the mirror than the heat conduction through the fibers. However, we found that crystal sapphire fiber can effectively convey the heat in place of conventional metal or fused silica fibers. We also found that a sapphire rod suspended by conventional style with sapphire fibers satisfies the requirement of a laser interferometric detector even at cryogenic temperature. Moreover, we have quantitatively evaluated the contamination speed of the cryogenic mirror that was exposed to room temperature vacuum wall through an aperture of a size of the mirror. These results shows the possibility of the realization of a cryogenic laser interferometer. For the application of a practical system, we have developed a cryogenic actuator system and applied this to a laser interferometer system and succeeded the locked operation. This operation is the first time of the demonstration of a cryogenic interferometer in the world. These results satisfies the original objective of the research program except the demonstration of the reduction of thermal noise itself using the interferometer. They are applied to 1200m baseline cryogenic laser interferometric gravitational wave detector in a succeeding research program planed to start from the next financial year, 2002. Less

  • Research Products

    (13 results)

All Other

All Publications (13 results)

  • [Publications] T.Uchiyama, et al.: "Cryogenic cooling of a sapphire mirror-suspension for interferometric gravitational wave detectors"Physics Letters A. 242. 211-214 (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Uchiyama, et al.: "Mechanical quality factor of a cryogenic sapphire test mass for gravitational wave detectors"Physics Letters A. 261. 5-11 (1999)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Uchiyama et al.: "Mechanical quality factor of a sapphire fiber at cryogenic temperatures"Physics Letter A. 273. 310-315 (2000)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] S.Miyoki et al.: "Cryogenic contamination of an ultra-low loss mirror for cryogenic laser interferometric gravitational wave detector"Cryogenics. 40. 61-66 (2000)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] S.Miyoki, et al.: "Cryogenic contamination speed for cryogenic laser interferometric gravitational wave detector"Cryogenics. 41. 415-420 (2001)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Tomaru, et al.: "Cryogenic measurement of the optical absorption coefficient in sapphire crystals at 1.064μm for the large-scale cryogenic GW telescope"Physics Letters A. 283. 80-84 (2002)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T. Uchiyama, D. Tatsumi, T. Tomaru, M. E. Tobar, K. Kuroda, T. Suzuki, N. Sato, A. Yamamoto, T. Haruyama and T. Shintomi: "Cryogenic cooling of a sapphire mirror-suspension for interferometric gravitational wave detection"Phys. Lett.. A242. 211-214 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] T. Uchiyama, T. Tomaru, M. E. Tobar, D. Tatsumi, S. Miyoki, M. Ohashi, K. Kuroda, T. Suzuki, N. Sato, T. Haruyama, A. Yamamoto and T. Shintomi: "Mechanical quality factor of a cryogenic sapphire test mass for gravitational wave detectors"Phys. Lett.. A261. 5-11 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] LCGT Collaboration (The first author, K. Kuroda and other 30 authors): "Large-scale cryogenic gravitational wave telescope"Int. J. Mod. Phys.. D8. 557-579 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] T. Uchiyama, T. Tomaru, D. Tatsumi, S. Miyoki, M. Ohashi, K. Kuroda, T. Suzuki, A. Yamamoto, T. Shintomi: "Mechanical quality fiber of a sapphire fiber at cryogenic temperatures"Phys. Lett.. A273. 310-315 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] "Cryogenic contamination of an ultr-low loss mirror for cryogenic laser interferometric gravitational wave detector"Cryogenics. 40. 61-66 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] T. Tomaru, T. Uchiyama, D. Tatsumi, S. Miyoki, M. Ohashi, K. Kuroda, T. Suzuki, A. Yamamoto, T. Shintomi: "Cryogenic measurement of the optical absorption coefficient in sapphire crystals at 1.064 μm for the large-scale cryogenic gravitational wave telescope"Phys. Lett.. A283. 80-84 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] S. Miyoki, T. Tomaru, H. Ishitsuka, M. Ohashi, K. Kuroda, D. Tatsumi, T. Uchiyama, T. Suzuki, N. Sato, T. Haruyama, A. Yamamoto, T. Shintomi: "Cryogenic contaminafion speed for cryogenic laser interferometric gravitational wave detector"Cryogenics. 41. 415-420 (2001)

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 2003-09-17  

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