Cosmogenic nuclides in cosmic dust

Spherules, found in the deep sea sediments and the polar ice, form a unique group of cosmic dust sample. Cosmogenic nuclides such as 10Be, 26Al contained in spherules will indicate many information about not only the origin and motion of the cosmic spherules themselves but also various physical phenomena which happened in the solar system. Recently, some attempts to measure the cosmogenic nuclides in spherules are successfully done with the technique of AMS (Accelerator Mass Spectrometry). In this article, the character of the cosmic ray and the interaction between the cosmic ray and the solid body are summarized first, which is necessary to interpret the data of the AMS measurements. Then, actual data are presented and examined. (author)