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

1)在东京大学MALT(微型分析实验室，串列加速器)用加速器质谱仪(AMS)进行了^&lt；10；Be和^&lt；26；Al的研究和开发工作。^&lt；10；BE和^&lt；26&gt；Al AMS测量的当前灵敏度分别为^&lt；10&gt；Be/^9Be=(0.5-1)x10^&lt；-13&gt；和^&lt；26&gt；Al/^&lt；27&gt；Al=(0.5-1)x10^&lt；-13&gt；2)含量分别为^&lt；10&gt；Be，^&lt；26&gt；Al和^&lt；53&gt；测定了布伦汉姆陨石(石质铁陨石)各部位的锰含量。这些数值被用于早先报道的陨石中核素产生的通用模型(Nagai等人，GCA1993)。3)北太平洋至南冰洋大气中~7Be和~(10)Be的纬度分布具有明显的特征，其最大值为~7Be和~(10&gt；Be)，在两个半球为20~30ﾟ，赤道附近和50~60ﾟS为极小值。Cau…更多的Se可能是通过湿降水或对流层大气的环流路径来消除气溶胶。北半球和南半球的平均值分别为1.23和1.95。这种差异可能是由于对流层和平流层之间的空气交换速率不同或大陆土壤的再悬浮造成的。4)KH96-5Hakuhho-Maru CRUSE期间在苏鲁海观测到的表层水中Be/7Be值为34.9。利用该值和大气中的1.23，估算出Be在海洋表层水中的滞留时间为1.2年。计算得到大气向地表水的沉积速度为1.64厘米/秒。根据~(10)Be/~(7Be)的变化，估算出~(10)Be/~(7)Be的沉积速度为23年/1000m。5)在赤道大西洋Ceara海隆的ODP925站采集的沉积物中测得~(10)Be的浓度。~(10)Be通量在7 Ma以上的变化和近2 Ma的高通量可以用亚马逊流域的陆源输入来解释。另一方面，由于全球Be产量的变化，没有观察到^&lt；10&>Be通量的变化。较少

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