A Novel Gap-Fin Design of Rotating Scatter Mask Collimator for Radiation Source Localization

Compared to directional radiation detection equipment, such as the gamma camera, the solution with a non-directional radiation sensor and a collimator has a lower cost and is applicable in scenes with strong radiation. Since the collimator can greatly improve the sensor’s ability to identify the direction of radiation sources, the collimator design is extremely important. In this article, aiming to address the misidentification problem of the existing Wall-Fin rotating scatter mask (RSM) collimator, a novel design (Gap-Fin) is proposed based on the optimized detector response curve (DRC). A model optimization method based on key parameters is proposed and quantitatively verified through simulations with Geant4. Simulations are also conducted to compare the optimized Gap-Fin design with the original design in scenarios with one and two sources, where different detection distances, particle energies, particle numbers, and shielding materials are used. Simulation results show that the optimized Gap-Fin design has better detection accuracy and anti-interference ability. In addition, the optimized collimator is applied to locate the radiation source both in simulation and a robot detection experiment, which shows the effectiveness of the novel collimator design in radiation source localization.