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

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）。结果表明，该模型适用于更大的物体和更重的屏蔽样品。3）北太平洋至南极海洋大气中^7 Be和^ Be的纬度分布<10>具有明显的特征，两半球的^7 Be和^ Be浓度在20至30 ° C左右出现最大值，在赤道附近和50至60 ° S附近出现最小值。这是由于北太平洋至南极海洋大气中^7 Be和^ Be的纬度分布具有明显的特征<10>，在两半球的20至30 ° C左右出现最大值，在赤道附近和50至60 ° S附近出现最小值。 ...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

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