Lightweight Omnidirectional Radiation Protection for a Photon-Counting Imaging System in Space Applications

Concerns about the impact of space radiation on spacecraft and their internal instruments have prompted the need for effective protection. However, excessive protection can increase the costs and difficulty of space launches, making it crucial to achieve better shielding protection of lighter weights. In real space orbits, we observed the interference of charged particles on photon-counting imaging detectors and plan to address this issue by adding a shielding ring to the side wall of the detector input terminal. Additionally, a local protection structure was proposed for electronics, where the outer edge was increased to enable particles to reach the same thickness as the shielding box within the PCB range. This approach resulted in an omnidirectional spatial shielding thickness that was nearly identical at any point on the PCB surface. Furthermore, we used the Monte Carlo method to calculate the energy loss of electrons and protons in materials such as aluminum (Al), tantalum (Ta), and high-density polyethylene (HDPE). Through this analysis, we determined the optimal mass ratio of Al, Ta, and HDPE to achieve the lowest ionization doses at an object's location in the particle environment of the FY-3 satellite orbit. This protection strategy provides a useful design concept for photoelectric detection instruments with high sensitivity.