On statistical models for fission track counts

The statistical basis for the usual analysis of fission track counts obtained by the external detector method is discussed and illustrated with examples. A consequence is that if any observed correlation between counts of spontaneous and induced tracks is due to heterogeneity in the density of uranium, then the model proposed by McGee and Johnson (1979)for assessing the experimental error is inappropriate and results based on it could be misleading. The same remark applies to the method proposed by Johnson, McGee, and Naeser (1979).