Using a gas-filled detector in a rotation modulation collimator system for near-field imaging

Rotation modulation collimators (RMC) are a class of nuclear imaging devices that are found in various applications. RMC are used for far-field applications, as in astronomy, and in near-field applications, as in environmental, medical and military uses. The typical detectors used in RMC system are scintillators and semi-conductors, which detect γ radiation only. This work investigates the utilization of gas-filled detectors, which detect  particles as well as γ rays. Hence, a simple RMC system is built that utilizes a Geiger-Muller (GM) tube as a detector. To help assess the new system, a direct image construction algorithm is developed. Results of the assessment show that the newly built system is well capable of imaging radiation sources in the near-field.