Directional gamma radiation detector system

A directional gamma radiation detector system for determining an angle under which a measured gamma radiation hits a gamma radiation detector system, comprises:

• at least two gamma radiation detectors arranged in close distance;
• detector electronics for operating the at least two gamma radiation detectors as spectrometers in a way that the detector electronics are collecting energy spectra of the detected gamma rays for each gamma radiation detector;
• and
• system electronics allowing the directional gamma radiation detector system to identify coincident events in the at least two gamma radiation detectors and set to conduct at least the following steps:
• collecting an energy spectrum E20 of the detected gamma rays in a first one of the at least two gamma radiation detectors by the corresponding detector electronics (250), limited to coincident events in a second one of the gamma radiation detectors,
• collecting an energy spectrum E30 of the detected coincident gamma rays in the second gamma radiation detector by the corresponding detector electronics (350),
• determining a mean energy <E20> of the first energy spectrum E20,
• determining a mean energy <E30> of the second energy spectrum E30, and
• determining the angle under which the measured gamma radiation hits the gamma radiation detector system by comparing the mean energy <E20> with the mean energy <E30>.