High Energy Nuclear Interactions with Matter and Nuclear Processes in Nature. Final Report.

摘要

The research conducted during the period 1965to 1975was concerned with two areas: (1) high energy proton interactions,and (2) nuclear reactions in nature. The systematics of high energy proton produced rare gas nuclides from Cu,Ag,Au,and U targets were investigated. It was found that the lower mass nuclides up to A approximately 30were produced mainly by fragment emission,while the higher mass nuclides were produced mainly by spallation except for U targets for which fission dominates. The existence of beta beta decay was firmly established for the first time on experimental grounds. The half-life of the beta beta decay exp 130Te--exp 130Xe was measured to be 2.2 x 10exp 21years. The meteorites St. Severin,Lost City,and Suchy Dul were investigated for cosmic ray proton produced rare gases. Cosmic ray exposure ages of 11, 8,and 23million years respectively were determined. At the same time,the K--Ar ages were found to be 4.4, 4.1,and 1.9billion years respectively. A model was proposed which allows a tektite strewn field to be at least 100km from the impact crater. The model removes one of the major constraints on the terrestrial origins of tektites. It was found that exp 228Ra diffuses from sea sediments and as such is a good tracer for studying bottom currents and diffusion processes in the sea. A list of publications is included. (ERA citation 02:011546)