On the frequency distributions per unit area of the dimensions of fission tracks revealed in an internal and external mineral surface and in the surface of an external detector

It is argued that present estimates of the efficiency with which fission tracks are counted in an internal and external mineral surface and in an external detector are not sufficiently reliable, and that more reliable estimates can, in principle, be derived from the frequency distributions per unit area of surface of the track dimensions. With this aim, Dakowski's (1978) equations for the frequency distributions of the projected lengths, etchable lengths, depths, and inclinations of fission tracks intersecting an internal mineral surface are extended to the external mineral surface and to the surface of an external detector. It is also shown that there exists a simple additive relationship between corresponding distributions in these three geometries. As part of these calculations, a formula is derived relating the range of a fission fragment originating in a mineral grain and crossing to an external detector to its ranges in each of these media separately