Measurement of the total-to-peak ratio of a low-energy germanium gamma-ray detector

The spatial dependence of the total-to-peak ratio for a closed-end coaxial n-type detector with a beryllium window was measured. For the measurements point sources containing pure X-ray emitters and X- and gamma-ray emitters, emitting photons in the energy range between 5 and 1115 keV were used. Departures of up to 10% from a total-to-peak ratio independent of the source position were found. They are attributed to the escape of germanium X-rays and scattered photons from the sensitive volume of the detector and to detection of radiation scattered in the insensitive parts of the detector.