Oral Session 12: Countermeasure and Transportation Code Measurements on radiation shielding efficacy of Polyethylene and Kevlar in the ISS (Columbus)

The study and optimization of material effectiveness as radiation shield is a mandatory step toward human space exploration. Passive radiation shielding is one of the most important element in the entire radiation coun-termeasures package. Crewmembers will never experience direct exposure to space radiation; they will be either inside some shelter (the spacecraft, a ‘base’) or in an EVA (Extra Vehicular Activity) suit. Understanding the radiation shielding features of materials is therefore an important step toward an optimization of shelters and suits con-struction in the quest for an integrated solution for radiation countermeasures. Materials are usually tested for their radiation shielding effectiveness first with Monte Carlo simulations, then on ground, using particle accelerators and a number of specific ions known to be abundant in space, and finally in space. Highly hydrogenated materials perform best as radiation shields. Polyethylene is right now seen as the material that merges a high level of hydrogenation, an easiness of handling and machining as well as an afford-able cost, and it is often referred as a sort of ‘standard ’ to which compare other materials ’ effectiveness. Kevlar has recently shown very interesting radiation shielding properties, and it is also known to have important characteristics toward debris shielding, and can be used, for example, in space suits. We have measured in the ISS the effectiveness of polyethylene and kevlar using three detectors of th