High-resolution Imaging Using a 48×48 Ge Array with Multiplexer Readout

We are developing an imaging technique for nuclear medicine that makes use of semiconductor arrays having a large number of separate pixels on a single slab that are read out by a monolithic integrated circuit called a multiplexer. The device is similar to a focal-plane array used for infrared imaging. Here we present results verifying the concept by using a Hughes 48×48 Ge PIN focal-plane array as a gamma-ray imaging system. The performance of this device as an imaging spectrometer was extraordinary, with a spatial resolution of 125 μm at 30 keV and an energy resolution of 2 keV FWHM (25-140 keV). The device performed well over a temperature range of 136-200 K. It is concluded that semiconductor detector arrays with multiplexer readout are a very attractive approach for a new generation of nuclear medicine imaging systems