ANALYTICAL AND EXPERIMENTAL PREDICTIONS OF FUSION NEUTRON RADIATION EFFECTS. VOLUME I. THEORETICAL AND EXPERIMENTAL STUDIES.
Technical rept. Jan 65-Jan 66,
HUGHES AIRCRAFT CO FULLERTON CA RADIATION EFFECTS RESEARCH DEPT
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Theoretical calculations were made of the energy deposited in silicon in ionization and elastic interactions by neutrons in a broad energy range from 60 keV to 15 MeV. This energy range is sufficient to predict fusion and fission neutron effects. Care was taken to calculate accurately the effects of atomic recoils, which are of primary importance for permanent effects in silicon at all neutron energies and account for about 30 percent of the transient effects at fusion neutron energies. Experiments were performed with a pulsed d-t neutron generator to test the calculation of the energy deposited in ionization in silicon due to fusion neutrons. There was general agreement of theory with experiment from 200 keV to 14 MeV. Rapid annealing experiments were performed with five silicon transistors at a pulsed reactor. Two annealing processes were observed one effective up to one millisecond after the pulse, and the other lasting over many decades of time out to several seconds. The data was used as evidence for a physical model involving defect clusters produced by atomic recoils. The first stage of annealing corresponded to annealing within the cluster, and the second stage to diffusion from, and subsequent recapture by, the cluster.
- Nuclear Physics and Elementary Particle Physics