Gamma-ray imaging with low fold segmented semiconductor detectors

For a practical implementation of Compton camera principles in γ-ray imaging applications, large volume detectors are needed for a good efficiency, whereas for position sensitivity, a considerable number of segments per detector is required. Often, the overall number of segments and associated processing electronics make such a system prohibitive due to the involved cost, and other technical difficulties. In order to overcome this impediment, a new technical concept is introduced, which uses large volume high resolution semiconductor detectors (Ge) having implemented a low fold segmentation of their electrodes, and employing advanced signal processing methods to provide unprecedented position sensitivity. Involving only 1/160 of the number of segments otherwise required, using the WPC (wavelet transform + pattern recognition + correlation analysis) signal analysis method, the effective position sensitivity of the detectors is expected to reach mm per spatial coordinate. WPC is a new procedure which decomposes and extracts multiple interactions occurring in the detector by analyzing the features of the digitized detector segment signals. Although applied for Ge detectors, the concepts and methods presented could be easily transferred to Si(Li) and other room temperature semiconductor detectors of large volume.