Temperature dependence of gain shift in γ-ray spectrometry system involving a long connecting cable

This work demonstrates the possibility of a gain shift or a peak-shape-deterioration with changes in the temperature of a long connecting cable between a pre-amplifier and a main amplifier in a Ge γ-ray spectrometry system. The tests were performed for 50m-long RG174/U and RG58C/U cables with and without the termination. Such a temperature effect may cause from the temperature dependence of the resistivity of a central copper wire. In order to minimize such temperature effects in a Ge γ-ray spectrometry, use of a terminator should be avoided.