Mechanisms of Transient Radiation Effects

Transient radiation effects are defined to be manifestations of electrons excited in materials, i. e., ionization effects. Manifestations of particular interest are the emission of secondary electrons from surfaces, conduction in ionized gases, semiconductors and insulators, and the emission and absorption of optical radiation by excess electrons. In each case the processes can be described as a sequence leading from the primary interaction of the incident nuclear radiation with an atom in the target material through the slowing down of the electrons which are detached in this interaction to the eventual recapture or trapping of the free electrons. Most of the phenomena can be described in terms of a mean lifetime for the electrons and a mobility. Assuming reasonable values for these quantities, calculations can be performed to estimate the order of magnitude of transient effects in typical materials and electronic components.