Particle Tracks

Abstract

There are two dating methods, the fission track and the α-recoil track, which are based on nuclear particle tracks. During nuclear fission and α-decay heavy nuclear particles acquire high kinetic energies. As a result of interactions with the atoms of solid state detectors, they leave along their path a trail of radiation damage: the latent particle track. In this way single decay events can be detected. Many minerals and glasses are able to record particle tracks. Fission tracks are formed during the spontaneous nuclear fission of ²³⁸U. The two heavy fission fragments leave a fission track of 10 – 20 μm length. The α-recoil tracks are formed during the α-decay of uranium and thorium as well as of their radioactive decay products. The nucleus left over by the α-particle recoils by a few 10^-2 μm. The diameter of latent particle tracks amounts to some 10^-3 μm.