Characterization of novel rotating scatter mask designs for gamma direction identification

摘要

The Rotating Scatter Mask system is a low cost, directional radiation detection system with a nearly 4_π field-of-view over a broad range of photon energies. However, the original mask design is limited by numerous similarities in the detector response directional modes. These similarities introduce potential misidentification errors when determining a source's direction. Previous studies identified a better mask design, the Mace, which significantly reduced the similarities between the modes. In this work, a new design class was simulated and compared to the Mace mask design using the modal assurance criterion to assess the differentiability between directional modes. At the expense of a reduced field-of-view, 93% of a full An steradians, these novel mask designs were shown to successfully decouple the angular components of the source's direction, improving the average criterion value by up to 66%. The new designs also significantly improved the system's detection efficiency, reducing the time to identify the source's direction by up to 60%, while enabling a simplified, alternative algorithm for identifying the source direction. This alternative approach, called the geometric correlation method, further improved detection efficiency leading to a near-real time analysis for locating a source direction with the Rotating Scatter Mask.