Optimization using Monte Carlo simulations of the thickness of a variable collimator for radiation monitoring

In this study, we used GATE v8.0 to optimize the design parameters for the layer thickness and the shape of holes in variable collimators with new methods for moving detectors and acquiring magnified images in real time. The optimized thickness was a combination of five layers with thicknesses of 6.0, 2.0, 4.0, 2.0, and 6.0 mm. Image magnification on variable and conventional pinhole collimators, designed with the same parameters, confirmed that the greater the magnification is, the more distinct the two sources are. The increase in the penetration and the scatter ratio caused by empty areas created during the process of implementing the pinhole form into layers resulted in an average sensitivity error of 3.95%, which reduced spatial resolution slightly.