Fission track dating
Price and Robert Walker showed how these fission tracks can be revealed to the human eye (aided by an optical microscope) by acid etching, forming the basis of a unique geochronometer (Price and Walker, 1962, 1963; Fleischer et al., 1964, 1965, 1975).
During the 1970s, the fission track community experimented with a number of alternative designs to turn induced track densities into (EDM), in which the induced tracks are recorded in a mica- (or plastic) detector attached to the polished grain mount during irradiation.
This detector is subsequently etched and counted separately (Fleischer and Hart, 1972; Hurford and Green, 1983; Hurford, 1990).
Equation 4 represents a classic case of a ‘matched pairs’ experimental design (Galbraith, 2010).
By counting the spontaneous and induced tracks over exactly the same area, the age calculation reduces to a simple comparison of two Poisson-distributed variables ().
Unfortunately, the EDM also has a number of practical shortcomings: U.