Abstract: (D, T) neutron radioactive sputtering yields

(D, T) neutrons have sufficient kinetic energy for various nuclear reactions such as (n,α), (n,p), and (n,2n) to occur. A series of experiments have been performed using a 14.8 MeV (d, t) neutron source in which the radioactive daughters ejected from the near surface region of the target material have been collected and measured. The geometry of the experimental arrangement was such that radioactive daughters ejected in the forward direction (neutron current direction) and backward direction were collected. A bar graph summary of the forward radioactive sputtering ratios obtained for a large variety of metals and also for 316 stainless steel is given. The graph includes the reaction producing the radioactive recoil and the half-life of the radioactive daughter. It can be seen that the sputtering ratio for all of the materials studied range from the mid-10-8 to mid-10-7 atoms/neutron range. No statistical differences in the radioactive sputtering ratios between annealed and cold worked niobium or between annealed and cold worked 316 stainless steel were observed. It is possible to determine an effective emission range of the radioactive recoil. Since the metal targets used in the experiments are thicker than heavy-ion ranges in metals, an effective emission range can be defined simply as the product of the ratio of the number of radioactive recoil atoms on the collector to the number of recoil atoms in the target and the thickness of the foil. For small ranges, elemental surface and near surface composition such as oxide and carbide layers may produce errors in the results because of uncertainties in the parent atom density