A comparison between spontaneous and induced fission-track annealing in apatite. Do induced fission track annealing models truly describe natural annealing in apatite?

All published fission-track annealing models in apatite have been established using the confined length of induced tracks rather than spontaneous tracks. Use of induced tracks is convenient as it helps to reduce the number ofapatite crystals requiredfor experiments, we can control the starting initial length for all samples and, through controlled irradiation we can obtain suitable track densities to produce good statistics on our measurements for all stages of the experiments.