A self-stabilizing scintillation detector system for the measurement of nuclear radiation, preferably gamma radiation, is provided, the system comprising a scintillation crystal, a photo detector, a photomultiplier (PMT) and one or two fast digital sampling analog to digital converters (ADC), where the scintillator is selected from a group of materials having a light decay time of at least 1 ns, and where the PMT is set to its highest possible gain. A first ADC for processing the single photo electron induced signals is connected to the PMT output, namely the anode output, this first ADC being set to operate with a very high sampling rate of at least 10 MHz, and a second ADC for processing the nuclear particle induced signals is connected to one of the PMT's dynodes with a significantly lower amplification.