Influence of radioactive filiation on measured release curves

Perturbation of measured release curves of radioactive nuclei by the decay of precursor nuclei in the target is investigated. The target is described by a simple model taking into account the direct production of the nucleus of interest by the reaction but also allowing decay of the isobaric precursor to take place specifically during diffusion or effusion. Their respective contributions to the observed ion currents can be enough different to lead to uncorrect analysis of the experimental release curves. As an example we discuss release curves of the pairs of neutron-rich isotopes ( Rb m 86 , 91Rb) and ( Cs m 130 , 139Cs) produced by proton-induced fission at the IRIS facility, Gatchina.