Optical studies of fission tracks in apatite

Fossil fission track damage in natural fluorapatite has been studied by absorption spectroscopy. It was found that for samples cut perpendicular to the c-axis, the dominant annealing process for the absorbing defects (identified as H(II)centers) is, in the early stage of annealing, diffusion to the sample surface with a measured diffusion coefficient of D = (1.2 +- 0.4) x 10-9 cm2 s-1 (at T = 673 K). In addition, we have also studied the properties of freshly induced fission tracks with the aim of using optical absorption detection to develop an alternative fission track dating method. (author)