14 MEV NEUTRON IRRADIATION EFFECT ON SUPERCONDUCTING MAGNET MATERIALS FOR FUSION REACTOR

摘要

Fusion reaction yields high energy neutron. It streams out of a plasma vacuum vessel and reaches superconducting magnets. This paper briefly overviews the essential empirical results on neutron irradiation effects on the superconducting magnet materials. The neutron irradiation generates vacancies, interstitials and clusters in the matrix. Regarding the A15 superconducting materials like Nb{sub}3Sn and Nb{sub}3Al, lower fluence of neutron will make the normal state resistivity increase resulting in increasing the critical current a little. More fluence will induce new pinning sites in the matrix and strengthen the existing pinning sites so that the critical current increases remarkably. Over 10{sup}22 n/m{sup}2 fluence will damage the matrix and the critical temperature decreases.