3D Compton image reconstruction using a moving 3D-position-sensitive room-temperature CdZnTe detector array

The ability to do real-time 4π Compton imaging is potentially useful when searching for radioactive sources with appropriate gamma-ray energy emissions. Stationary 4π Compton imagers have the ability to reconstruct the correct direction to gamma-ray point sources; however, if the source is positioned far from the detector compared to the dimensions of the detector, the distance from the source to the detector is uncertain. If the same detector moves and the position of the detector as a function of time is known, a 3D radiation image can be made. This work describes the use of room-temperature 3D-position-sensing CdZnTe detectors in motion to create a 3D radiation map of sources in an unknown environment. Experimental results show that an array composed of 18 CdZnTe detectors, can accurately map out a room of sources. Finally, a pair of fisheye cameras are used to correlate the reconstructed hotspot in 3D Cartesian space to a physical location in the optical image.