PILE NEUTRON CAPTURE CROSS SECTIONS OF Co60* (10.5 MIN.) AND Co60 (5.25 YR.)

Abstract

Activity of approximately 105 min. half-life has been detected in samples of Co59 irradiated at high neutron fluxes in the NRX reactor. By a study of the yield as a function of neutron flux and time of irradiation this activity was demonstrated to be due to Co61 (105 min.) formed by neutron capture in Co60. The pile neutron capture cross sections were found to be 95 ± 45 barns and 6.0 ± 1.4 barns for the Co60* (10.5 min.) and Co60 (5.25 yr.) isomers respectively.