A practical fan-beam design and reconstruction algorithm for Active and Passive Computed Tomography of radioactive waste barrels

Active and Passive CT (A&PCT) of waste barrels is mostly carried out in parallel beam configuration due to its relative ease of implementation. This necessitates either using a single detector-source pair and translating the barrel or using multiple detector-source pairs for increasing the scanning speed. Additionally, because the use of bulky HPGe detectors may limit the number of detectors used in both active and passive modes, we propose to use 1″×1″ LaBr3(Ce) scintillators. This paper describes a practical fan-beam reconstruction for A&PCT imaging of waste barrels. A fan beam system model has been computed analytically and reconstruction done using MLEM algorithm. The results are compared with analytical reconstruction.