Preparation of highly enriched O-17 samples for neutron-induced reaction studies

摘要

Suitable O-17 samples are required for the study of the O-17(n,alpha)C-14 reaction with various detectors, The electrospraying of metal oxides enriched in O-17 onto an Al substrate yielded negative results: no O-17(n(th),alpha) reactions were observed when irradiating these samples with thermal neutrons, These tests demonstrated the need to minimize the B-10 content in sample and backing, since the B-10(n(th),alpha(1)) reaction causes a strongly disturbing background. Good results were obtained in the reactor experiments using gaseous samples (O-17 enrichments of 58.2, 72.1 and 85.5) with a dedicated experimental setup. The experimental conditions being quite different at accelerators, an alternative method was developed to prepare samples suited for use in ionization chambers, For this purpose, O-17 ions were implanted in ultra-pure Al foils. The thickest sample prepared in this way contains 8 x 10(18) atoms of O-17, with a B-10/O-17 ratio of 10(-4). (C) 2001 Elsevier Science B.V. All rights reserved. References: 7