Speaker
Description
Through the utilization of the GEANT4 tool integrated into SPENVIS, I aim to demonstrate the practicality and efficacy of simulating radiation hazards within spacecrafts orbiting in Low Earth Orbit (LEO). This research has two primary objectives: first, to assess the accuracy of these simulations by comparing them with historical dose assessments conducted on the International Space Station (ISS); and second, to emphasize the value of advanced simulation tools in exploring radiation hazards beyond the limitations of traditional dose measurements. By benchmarking simulation outcomes against measured dose values, we gain the ability to delve into the specific secondary products generated during radiation interactions. Additionally, this research sheds light on the intricate nature of novel shielding design challenges. The shift in interest from homogeneous dense materials to composite structures poses significant hurdles, since current simulation tools have not yet adapted to provide users with the capability to accurately model these intricate concepts within the simulation environment.
Moreover, while many investigations concentrate on introducing novel materials to enhance space safety, they frequently overlook the consequential influence of pre-existing spacecraft structures, including Micro-Meteoroid and Orbital Debris (MMOD) shielding, metal racks, and hull components. These elements significantly affect radiation interactions, necessitating their inclusion in simulations to provide accurate assessment of shielding efficiency. This further highlights the importance of advancing the capabilities of these simulation tools to encompass a more comprehensive approach to material characterization.
For instance, novel approaches often advocate for the use of polymers to create lighter shielding options. However, the suitability of such materials is highly contingent on the types of radiation that successfully penetrate existing spacecraft structures. In my preliminary investigation, it became apparent that a significant portion of the radiation inside the ISS consists of secondary neutrons and gamma rays. This observation underscores the limitations of polymer-based solutions, as they may necessitate exceptionally thick shielding, and even then, materials like polyethylene exhibit a significant decrease in efficiency with increasing thickness, further compounding the challenge. This scenario exemplifies the critical importance of studying secondary products in radiation shielding assessments, a task made feasible through the application of simulation tools.
