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Dumand--- II Stage Project

Research Project

Project/Area Number 01044030
Research Category

Grant-in-Aid for international Scientific Research

Allocation TypeSingle-year Grants
SectionJoint Research
Research InstitutionUniversity of Tokyo

Principal Investigator

OHASHI Yozo  Univ. of Tokyo・ICRR, Associated Professor, 宇宙線研究所, 助教授 (80022599)

Co-Investigator(Kenkyū-buntansha) LEARNED John  University of Hawaii, Professor, 教授
UEHARA Sadaharu  National Lab. for HE Phys., Assis. Prof., 助手 (70176626)
SAKUDA Makoto  National Lab. for HE Phys., Assis. Prof., 助手 (40178596)
HAYASHINO Tomoki  Tohoku Univ. ・Faculty of Science., Assis. Prof., 理学部, 助手 (10167596)
YAMAGUCHI Akira  Tohoku Univ. ・Faculty of Science., Assoc. Prof., 理学部, 助教授 (60004470)
TANAKA Sho  Tohoku Univ. ・Faculty of Science., Professor, 理学部, 教授 (70004306)
YAMAMOTO Isao  Okayama Science Univ. ・Faculty of Engineering., Assoc. Prof., 工学部, 助教授 (50090220)
KITAMURA Takashi  Kinki Univ. ・Inst. Sci. & Tech., Professor, 理工学研究所, 教授 (10013426)
KOBAYAKAWA Keizo  Kobe Univ. ・College of Liberal Arts, Professor, 教養部, 教授 (00031287)
MITSUI Kiyomi  Univ. of Tokyo・ICRR, Assistant Professor, 宇宙線研究所, 助手 (80013340)
OKADA Atsushi  Univ. of Tokyo・ICRR, Assistant Professor, 宇宙線研究所, 助手 (90013341)
Project Period (FY) 1989 – 1990
Project Status Completed (Fiscal Year 1990)
Budget Amount *help
¥6,300,000 (Direct Cost: ¥6,300,000)
Fiscal Year 1990: ¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 1989: ¥3,000,000 (Direct Cost: ¥3,000,000)
KeywordsCosmic neutrino / Neutrino oscillation / Large-size PMT / Deep sea / Bioluminescence
Research Abstract

1. At the international collaboration meetings scientists from Japan, U. S. and Europe have discussed details of the DUMAND II including a construction schedule. The detector consists of one central string and 8 strings arranged in an octagon with 40m separation. Each string has 24 Optical Modules with 10m spacing. Construction of the first 3 strings at depth of 4,800m, off the Island of Hawaii will be finished till 1992.
2. The main goal of the DUMAND is detection of VHE cosmic neutrino from active objects. Mt. Hopkins group has observed VHE gamma-rays from Crab Nebula at a flux level of 7 x 10^<-11>/cm^2・s (*400GeV). If the observed gamma-ray originates from hadron processes, the DUMAND II will be able to detect neutrino signals from the object. Recently, some theorists have calculated flux of HE neutrinos from diffuse sources, such as Cosmic Strings and Active Galactic Neuclei. Both of these diffuse sources are expected to become dominant and distinguishable from atmospheric neutrino … More s at energy from about 10TeV. At FNAL, construction of an intense 150GeV booster is under planning. DUMAND group has presented to FNAL a letter of intent, a long baseline neutrino oscillation project. A distance between DUMAND and FNAL, about 6,200km, is suitable for the study of neutrino oscillation in matter.
3. From experimental results using PMT we found background light due to bioluminescence is effective only in a limited area of each optical detector and can be removed by coincidence method. Using a highly sensitive video camera images of luminous objects were recorded in the deep ocean. Observed data confirmed that intensity of biolight depends strongly on mechanical stimulation. Video records tells us that the flux of luminous objects is much smaller at DUMAND site than near Japan Island.
4. Neutrino events are detected by measuring Cerenkov light emitted by secondary particles in the sea water. Considering background light in the deep ocean, characteristics of DUMAND array such as effective area, angular resolution and false event rate were simulated. A method to discriminate parallel muon events against high energy single muon event was also examined.
5. Optical module is composed of 15" PMT, enclosed in a pressure housing made of glass. By optimizing a cathode shape and a dynode structure, PMT is improved on pulse height and timing resolutions. Associating electronics are designed to match with 1ns digitization, and to record both of pulse height and pulse width of output signals. Less

Report

(1 results)
  • 1990 Final Research Report Summary
  • Research Products

    (10 results)

All Other

All Publications (10 results)

  • [Publications] S.Matsuno et al.: "Single Photon Light Detector for Deep Ocean Applications" Nucl.Inst.& Meth.A276. 359-366 (1989)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] J.Babson et al.: "CosmicーRay Muons in the Deep Ocean" Phys.Rev.43. 3613-3620 (1990)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] M.Webster et al.: "Mechanical Stimulation on Biolumi nescence in the Deep Pacific Ocean" Deep Sea Research.

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] T.kitamura et al.: "Scattering Angle of Cosmic Ray Muons with Energy Loss Deep Underground (II)" Proc.of 21th.ICRC. 9. 314-317 (1990)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] A.Okada: "Simulation of MultiーMuon Detection in the DUMAND II Array" Proc.of the DUMAND Optical Module Workshop, Sendai. 50-66 (1990)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] S. Matsuno et al.: "Single Photon Light Detector for the Deep Ocean Application" Nucl. Instr. & Meth.A276. 359-366 (1989)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] J. Babson et al.: "Cosmic-Ray Muons in the Deep Ocean" Phys. Rev.42. 3613-3620 (1990)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] M. Webster et al.: "Mechanical Stimulation on Bioluminescence in the Deep Pacific Ocean" submitted to Deep Sea Research.

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] T. Kitamura et al.: "Scattering Angle of Cosmic Ray Muons with Energy Loss Deep Underground (II)" Proc. of 21th. ICRC. 9. 314-317 (1990)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] A. Okada: "Simulation of Multi-Muon Detection in the DUMAND II Array" Proc. of the DUMAND Optical Module Workshop, Sendai. 50-66 (1990)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1990 Final Research Report Summary

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Published: 1989-04-01   Modified: 2017-10-05  

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