Coincidence Experiments with Coaxial Ge(Li) Detectors in the Low Energy Range

A γ-γ coincidence arrangement employing two large volume (20 cm3) Ge(Li) coaxial detectors has been realized. Each diode has two isolated outputs, one of which yields the energy information of the incident radiation and the other one the timing signal. The prompt resolution curve obtained with a 60Co source has a full width at half maximum of 11 ns. Coincidence γ-ray spectra are observed with one Ge(Li) detector when the other is gated on the 1333 keV full energy peak. The use of a 30 ns coincidence resolving time results in an undistorted coincidence spectrum for energies higher than about 150 keV. In order to illustrate the applications of this technique, results obtained in γ-γ coincidence experiments with the complex γ-ray emitter 132I are presented and discussed.