Figure 7
662 keV photopeaks of the measured 137Cs spectra from a collecting anode strip at different cathode bias voltages; fixed drift strip voltages (adjacent drift strips: −100 V; central drift strips: −200 V) are used. The detector, irradiated in PTF geometry, shows the best energy resolution (1.3% FHWM at 661.7 keV) at a cathode voltage of −350 V (583 V cm−1). |