Investigations towards evaluating the contribution of (α + Al, Si) interactions to fossil tracks in muscovite mica track detectors

In order to characterize the tracks in the muscovite mica detector generated by Al and Si nuclei recoiling after the interaction with energetic alpha particles from the decay chains of the U and Th present in the mineral as impurities, two experiments have been performed: (1) irradiation of the muscovite detectors with 6, 9 and 12 MeV alpha particles produced by a Van de Graaff tandem accelerator, and (2) exposures of the muscovite detectors to 8.8 MeV alpha particles from a Th chemical compound under radioactive equilibrium. After irradiation, the muscovite detectors were chemically etched, and the tracks studied by optical microscopy. Both experiments led to the conclusion that the recoiling nuclei from interactions with high energy alpha particles have a track pattern which is different from those presented by fission fragments or heavy ions from cluster radioactivity.