Thermal and fission neutron-produced defect configurations in platinum

An experimental procedure employing resistivity measurements was used to observe the production of free interstitials and vacancies in platinum by atomic recoils produced from thermal neutron capture and fission neutron collision. For thermal neutrons, which produce damage much like fast electrons, free defect production increased nearly a factor of two with increasing irradiation temperature from 30 to 280 K. This is attributed to the increasing thermal dissociation of correlated pairs into free defects. From low-temperature recovery studies it is known that thermal neutrons produce damage which has a large Isub(D) recovery substage indicating an abundant production of correlated pairs. Although the correlated pair population is less in similar recovery studies of the high-energy atomic recoils associated with fission neutron damage, it is still large enough that one would expect to observe the effects of thermal dissociation, or in other terms, the temperature dependence of the I-V recombination volume. (Auth.)