ABSTRACT
Radionuclides that are linked to one another by the processes of radioactive decay have relative concentrations that can be calculated by the simple laws of radioactive in-growth or, in more complicated cases, by the Bateman equations. If a time exists at which all descendant radionuclides have been removed from a parent material, that time can be determined through radiochemical separations and the subsequent measurement of the relative concentrations of mothers and daughters at a later time. The interval between the time that the sample was purified and the time that it was subsequently analyzed is defined as the “age” of the material at the analysis time. However, this technique does not apply when the half-lives of the descendant nuclides involved in the determination become significantly shorter than the elapsed time.
