Unbiased equations for 95Zr-95Nb chronometry

Formulae are presented for 95Zr-95Nb chronometry of a nuclear event. In particular, they allow for a bias-free calculation of the moment of a nuclear explosion, based solely on a measurement of the produced activity ratio of 95Zr and 95Nb in a finite time interval. Also uncertainty propagation factors are presented, which relate the relative uncertainty on the nuclear decay data and activity ratio measurements with the relative uncertainty on the elapsed time. This allows for the calculation of an uncertainty budget, without the need for Monte Carlo simulations. The equations are applied to a set of measurement data and consistency is demonstrated.