3D-position-sensitive compact scintillation detector as absorber for a Compton-camera

An absorption detector based on scintillator material and position-sensitive photomultipliers for a high resolution Compton-Camera prototype has been developed. The design of the Compton-Camera puts several demands on the absorption detector. For coincidence measurements it is necessary to have a very fast trigger signal and a fast signal output, due to the high rate of events. The energy of the primary photons requires the use of a thick scintillator block as an absorber, causing the problem of parallax effects in event reconstruction. Therefore a 3D-position resolution of the interaction point is needed. This is achieved by using position-sensitive photomultiplier tubes (PS-PMTs) for the readout of the scintillator. The design specifications and the performance of the complete detector will be presented in this paper.