Spectroscopic study of short lived, high spin isomers through the recoil method

The γ and conversion electron de-excitation spectra of nuclei, produced through (HI, χn) reactions, are spoiled by various phenomena, most of them related to the reaction itself. When, in the isotopes studied, one or several isomers are present, the half-life of the higher energy one being about 15 ns or more, then the compound nucleus recoil method can provide much cleaner spectra. This method is extensively described and discussed here, together with others, more briefly treated, also meant to reduce the unwanted effects; these techniques may be used either separately or combined, depending on the experiments performed. Examples of the results obtained are shown to illustrate the substantial improvements reached.