A Novel Scatter Detector for High-Resolution SPECT Imaging With Compton Telescopes

We propose a novel Silicon Drift Detector (SDD) that can fulfill the demanding requirements of the ideal scatter detector for a high-resolution Compton Camera for medical imaging. This kind of detector demonstrates excellent performance in terms of energy and position resolution, maximum readout rate and the more relevant results are reported. The SDD proposed here is based on a multilinear architecture [controlled drift detector (CDD)] in which the backside has been segmented and instrumented to pick up the signal induced by the electron-hole (e-h) pairs generated by the interaction thus providing a fast coincidence signal between the recoil electron signal and the scattered gamma-ray signal. Several measurements have been carried out to study the shape of the induced signals and the achievable time resolution. Experimental tests with annihilation photons of a ²² Na source in a time coincidence setup showed best time resolution of 6 ns FWHM. These results confirm that SDD technology with fast pickup on the back electrodes and optimized design has the potential to develop a Compton telescope with Doppler limited performance for medical imaging