4.2 Detector energy resolution
The energy resolution of a detector is a measure of its ability to distinguish between two gamma rays or alpha particles having slightly different energies. This is usually defined as the full width of a peak at half the maximum amplitude (FWHM) divided by its energy.
The energy resolution is usually specified using some reference energies: in gamma spectrometry the conventional energies (in kilo electron volts, keV) are 122 (57Co), 662 (137Cs) and 1176 (60Co).
