Mechanisms and kinetics of nuclear track etching and annealing: Free energy analysis of damage in fission fragment tracks

Mechanisms and kinetics of etching and annealing of fission fragment tracks in CR-39 have been investigated. Kinetics of bulk etching and that of fission fragment track etching in CR-39 are described in a systematic manner. Activation energies of etching and annealing were determined from the experimental results through Arrhenius type, t = t o exp ( E a / k B T ) , empirical relationships and models. The increase of free energy in fission fragment track formation in CR-39 is also determined from the measurements of track parameters. Activation barriers of bulk etching, track etching and track annealing in CR-39 are compared and discussed. This paper presents an anatomy of fission fragment tracks. Analyses of experimental results and comparison of above mentioned energies have yielded the important physics information usable in nuclear track methodologies, including nuclear geophysics and geochemistry, and radiation damage in solids.