Application of Accelerator Mass Spectrometry for Cosmo-and Earth-Sciences.

加速器质谱在宇宙和地球科学中的应用。

• 批准号: 06453011
• 负责人: NAGAI Hisao
• 金额: $ 4.03万
• 依托单位: Nihon University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06453011/
• 关键词: Accelerator Mass Spectrometry; Atmosphere; Sea Water; Deep Sea Sediment; Cosmogenic Nuclide; Beryllium-10; Beryllium-7; Aluminum-26; 隕石; 宇宙生成核種

1) Research and development work was performed for measurements of ^<10>Be and ^<26>Al with Accelerator Mass Spectrometry (AMS) at MALT (Micro Analysis Laboratory, Tandem accelerator), University of Tokyo. Current sensitivities for ^<10>Be and ^<26>Al AMS measurements are ^<10>Be/^9Be=(0.5-1) x10^<-13> and ^<26>Al/^<27>Al=(0.5-1) x10^<-13>, respectively.2) Contents of ^<10>Be, ^<26>Al and ^<53>Mn in various parts of the Brenham pallasite (stony iron meteorite) were determined. These values were adopted to the universal model for nuclide production in meteorites, which was reported earlier (Nagai et al., GCA1993). As a result, this model was proved to be applicable for the larger body and the heavier shielding samples.3) The latitudinal distributions of ^7Be and ^<10>Be in the atmosphere over North Pacific Ocean to Antarctic Ocean, have clear features which has maxima of ^7Be and ^<10>Be concentrations around 20 to 30ﾟ in both hemisphere, and minima around equator and 50 to 60ﾟS.The cau … More se for this feature may be elimination of aerosol by wet precipitationor circulation path of tropospheric atmosphere. The average value of ^<10>Be/^7Be were 1.23 and 1.95 in the northern hemisphere and in the southern hemisphere, respectively. This discrepancy may derived from different exchange rate of air between troposphere and stratosphere or resuspension of soil in the continent.4) Observed ^<10>Be/^7Be value in the ocean surface water in Sulu Sea during KH96-5 Hakuhho-maru cruse were 34.9. Using this value and 1.23 in the atmosphere, the residence time of Be in the ocean surface water was estimated to 1.2 year. The deposition velocity from atmosphere to surface water was calculated to 1.64 cm/sec. Based on ^<10>Be/^7Be variation, the deposition velocity of Be between surface and middle water, i.e.60 to 100 m depth, also estimated to 23year/1000m.5) The ^<10>Be concentration was measured in the sediment collected at ODP Site 925 on the Ceara Rise in the equatorial Atlantic. The variation of ^<10>Be flux over 7Ma and the high ^<10>Be flux in the last 2Ma could be explained by terrigeous input from Amazon drainage. On the other hand, the variation of ^<10>Be flux derived from the global changes in ^<10>Be production rate did not observed. Less

1)在<10><26>东京大学的MALT（微型分析实验室，串联加速器）进行了利用加速器质谱（AMS）测量1Be和1Al的研究和开发工作。AMS测量的灵敏度<10><26>分别为：^<10>Be/^9 Be =（0.5-1）× 10 ~（-1）^<-13>和^<26>Al/^<27>Al=（0.5-1）× 10 ~（-1）^<-13>。2）测定了<10><26><53>布伦汉姆石铁陨石各部分的^ Be、^ Al和^ Mn含量。这些值被用于陨石中核素产生的通用模型，该模型在早些时候被报道（永井等人，GCA 1993）。3）<10>北太平洋至南大洋大气中^7Be和^ Be的纬向分布特征明显，在南北半球20 ~ 30 ° S处浓度最高，在赤道附近和50 ~ 60 ° S处浓度最低，这是由于大气中的^7Be和^ Be浓度在南北半球的分布特征不同，而在北太平洋和南大洋的分布特征<10>不同 ...更多信息 这一特征的成因可能是湿降水对气溶胶的消除或对流层大气环流路径。北方<10>半球和南半球的^ Be/^7Be平均值分别为1.23和1.95。这种差异可能是由于对流层和平流层之间空气交换速率不同或大陆土壤再悬浮所致。4）<10>KH 96 -5白令海-丸壳层期间苏禄海表层海水中观测到的^ Be/^7Be值为34.9。利用该值和大气中的1.23，估计Be在海洋表面水中的停留时间为1.2年。从大气到地表水的沉积速度计算为1.64厘米/秒。5<10>）在赤道大西洋塞阿拉海隆的ODP 925站，测量了表层水和中层水（60 ~ 100 m深度）之间的沉积速率<10>。7 <10>Ma以上的^ Be通量变化和<10>近2 Ma的高^ Be通量可以用来自亚马逊流域的陆源输入来解释。另一方面，<10>未观察到由^ Be生成率的全球变化引起的^ Be通量的变化<10>。少

项目成果

U.Zoppi, H.Matsuzaki, K.Kobayashi, M.Imamura, H.Nagai, S.Hatori, C.Nakano and Y.Sunohara: "New interpretation of the ^<10>Be and ^<26>Al content in cosmic spherules." Nuclear Instruments and Methods in Physics Research. B123. 319-323 (1997)

U.Zoppi、H.Matsuzaki、K.Kobayashi、M.Imamura、H.Nagai、S.Hatori、C.Nakano 和 Y.Sunohara：“对 ^<10>Be 和 ^<26>Al 含量的新解释

Koichi Kobayashi: "Current status of AMS system at the University of Tokyo" Nuclear Instruments and Methods inPhysics Research. B123. 107-111 (1997)

Koichi Kobayashi：“东京大学 AMS 系统的现状”核仪器和物理研究方法。

K.Kobayashi, S.Hatori, H.Nagai, K.Yoshida, M.Imamura, H.Matsuzaki, M.Murayama, M.Sakamoto, Y.Aramaki, M.Tanikawa, S.Shibata, H.Ohashi, U.Zoppi, C.Nakano, Y.Sunohara and T.Saitoh: "Current status of the AMS system at the University of Tokyo." Nuclear Instr

K.Kobayashi、S.Hatori、H.Nagai、K.Yoshida、M.Imamura、H.Matsuzaki、M.Murayama、M.Sakamoto、Y.Aramaki、M.Tanikawa、S.Shibata、H.Ohashi、U.

M.Murayama, H.Nagai, M.Imamura, S.Hatori, K.Kobayashi and A.Taira: "^<10>Be and ^9Be concentrations in the deep sea sediments at ODP Site 925B,Ceara Rise in the western equatorial Atlantic ; Implication of ^<10>Be flux change." Proceedings of the Ocean Dr

M.Murayama、H.Nagai、M.Imamura、S.Hatori、K.Kobayashi 和 A.Taira：“赤道西部塞阿拉海隆 ODP 站点 925B 的深海沉积物中^<10>Be 和 ^9Be 浓度

Masatake Honda: "Determination for natural yttrium along with rare earths by neutron activation." Geochemical Journal(to be published). 29. (1995)

Masatake Honda：“通过中子活化测定天然钇和稀土。”