Electron-gamma and electron-electron coincidence spectrometers with semiconductor counters

Abstract

A special vacuum chamber containing a lithium drifted silicon detector and the radioactive source has been designed for electron-gamma coincidences. The gamma rays were detected outside it with conventional scintillation counters. A further modification of this chamber was done placing into it a second silicon detector in front of the former, thus obtaining an electron-electron coincidence spectrometer. Conversion coefficients corresponding to the transitions of 0.161 MeV and 0.0795 MeV in133Cs have been determined. An additional measurement of the conversion coefficient corresponding to the 0.279-MeV transition in203Tl has been performed by means of beta continuum-electron conversion coincidences. The values obtained are: ακ (0.161) = 0.18 ± 0.03 (K/LM= 5.2 ± 0.8); ακ (0.0795) = 1.8 ± 0.4 (K/LM= 5.5 ± 1.4); ακ (0.279) = 0.14 ± 0.03 (K/LM= 2.4 ± 0.3).