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Structure and physical properties of impure amorphous interstellar icy grains

Research Project

Project/Area Number 09304050
Research Category

Grant-in-Aid for Scientific Research (A)

Allocation TypeSingle-year Grants
Section一般
Research Field Petrology/Mineralogy/Science of ore deposit
Research InstitutionHOKKAIDO UNIVERSITY

Principal Investigator

AKIRA Kouichi  Inst. Low Temp. Sci., Hokkaido Univ., Prof., 低温科学研究所, 教授 (60161866)

Co-Investigator(Kenkyū-buntansha) WATANABE Naoki  Inst. Low Temp. Sci., Hokkaido Univ., Inst., 低温科学研究所, 助手 (50271531)
荒川 政彦  北海道大学, 低温科学研究所, 助手 (10222738)
Project Period (FY) 1997 – 1999
Project Status Completed (Fiscal Year 1999)
Budget Amount *help
¥38,500,000 (Direct Cost: ¥38,500,000)
Fiscal Year 1999: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1998: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1997: ¥34,000,000 (Direct Cost: ¥34,000,000)
Keywordsamorphous ice / fine particles / low temperature / atomic force microscope / structure / comet / アモロフォス氷
Research Abstract

The following research was carried out on the formation and metamorphism of amorphous icy grains and origin and evolution of comets using newly developed ultrahigh-vacuum very low temperature atomic force microscope and existing equipments :
1) By irradiating the ultraviolet rays onto amorphous ice thin film, we analyze the formation of hydrogen molecule quantitatively. In addition, the reaction cross section was measured, and the reaction mechanism was decided.
2) The measurements on physical properties of impure amorphous ices were carried out. The thermal conductivity of impure amorphous ice was found to be 2-3 orders of magnitude smaller than that of the amorphous ice without the defect. As a result of the differential thermal analysis, we found that the crystallization of amorphous ices including impurities were endothermic reaction.
3) There results clearly shows that the some properties of impure amorphous ices strongly depends on their defect structure in amorphous ices.
4) On the basis of the above results, we have calculated the thermal history of comet nucleus. We found that runaway crystallization considered until now could not be occurred in the actual comet nucleus.

Report

(4 results)
  • 1999 Annual Research Report   Final Research Report Summary
  • 1998 Annual Research Report
  • 1997 Annual Research Report
  • Research Products

    (24 results)

All Other

All Publications (24 results)

  • [Publications] Kouchi A.et al.: "Crystallization Heat of Impure Amorphous H2O Ice"Geophys.Res.Lett.. (in press).

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] Watanabe N.et al.: "Measurement of D2 yields from amorphous ice by UV irradiation at 12 K"Astrophys.J.. (in press).

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] Kouchi A.et al.: "New methods for making amorphous icy grains for comet nucleus simulation experiments"Proc.32nd ISAS Lunar and Planetary Symp.. 121-124 (1999)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] 香内晃: "宇宙のアモルファス物質"応用物理. 68. 1179-1180 (1999)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] Kouchi, A. et al.: "Crystallization Heat of Impure Amorphous H2O Ice."Geophys. Res. Lett.. (in press).

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] Watanabe, N. et al.: "Measurement of D2 yields from amorphous ice by UV irradiation at 12 K."Astrophys. J.. (in press).

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] Kouchi, A. et al.: "New methods for making amorphous icy grains for comet nucleus simulation experiments."Proc. 32nd ISAS Lunar and Planetary Symp.. 121-124 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] Kouchi, A.: "Amorphous materials in space (in Japanese)"Applied Physics. 68. 1179-1180 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] Kouchi, A., et al.: "Crystallization Heat of Impure Amorphous H_20 Ice"Geophys. Res. Lett. in press

    • Related Report
      1999 Annual Research Report
  • [Publications] Watanabe, N., et al.: "Measurement of D2 yields from amorphous ice by UV irradiation at 12 K"Astrophys. J.. in press

    • Related Report
      1999 Annual Research Report
  • [Publications] Kouchi, A., et al.: "New methods for making amorphous icy grains for comet nucleus simulation experiments"Proc. 32nd ISAS Lunar and Planetary Symp.. 121-124 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] 香内晃: "宇宙のアモルファス物質"応用物理. 68. 1179-1180 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] Arakawa,M.: "Collisional disruption of ice by high velocity impact" Proc.31th ISAS Lunar and Planetary Symp. 13-16 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] Sugi,N., M.Arakawa, A.Kouchi and N.Maeno: "In-situ mass spectrometric observation of impact vaporization of water-ice at low temperatures" Geophys.Res.Lett.25. 837-840 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] Higa,M., M.Arakawa and N.Maeno: "Size dependence of restitution coefficients of ice in relation to collision strength" Icarus. 133. 310-320 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] Jeniskinns,P., D.F.Blake and A.Kouchi: "Amorophous water ice- A solar system material" in Solar Syytem Ices (ed.Schmitt et al.). 139-155

    • Related Report
      1998 Annual Research Report
  • [Publications] N.Watanabe, Y.Awaya, A.Fujino, Y.Itoh, M.Kitajima, T.M.Kojima, M.Oura, K.Okuma, M.Sano, T.Sekioka,and T.Koizumi: "“Photoion-yield spetra of in the 4d-threshold energy region"" J.Phys.B 31. 4137-4141 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] E.Shigemasa, J.Adachi, K.Soejima, N.Watanabe, A.Yagishita,and N.A.Cherepkov: "“Diret Ditermination of Partial Wave Contributions in sigma *Shape Resonance of CO Molecules"" Phys.Rev.Lett.80. 1622-1625 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] N.Watanabe, J.Adachi, K.Soejima: "Fixed-molecule ls sigma_g,u photoelectron angular distributions as a probe of sigma_g^* and sigma_u^* shape resonances of CO_2" Physical Review Letters. 78. 4910-4913 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] M.Sano, N.Watanabe, Y.Awaya: "Photoionization of 4d-electrons in singly-charged Xe ions" Journal of Physics. B29. 5305-5313 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] T.Koizumi, N.Watanabe: "4d Photoionization of Multiply Charghed Xe^q+(q=1-3) Ions" Physica Scripta. T73. 131-132 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] Jenniskens P, Blake D.F. and Kouchi A.: "Amorphous water ice:a solar system material." Solar System Ices. 139-155 (1998)

    • Related Report
      1997 Annual Research Report
  • [Publications] Sugi N., Arakawa M., Kouchi,A., and Maeno N.: "In-situ mass spectrometric observation of impact vaporization of water ice at low temperatures" Geophys.Res.Lett.(in press). (1998)

    • Related Report
      1997 Annual Research Report
  • [Publications] Arakawa,M. and N.Maeno: "Mechanical Strength of Polycrystalline Ice under Uniaxial Compression" Cold Regions Science and Technology. (in press).

    • Related Report
      1997 Annual Research Report

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Published: 1997-04-01   Modified: 2016-04-21  

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