Update on the development of SOI microdosimetry: current status

Microdosimetry is extremely useful for dosimetry in any unknown mixed radiation fields. The Centre for Medical Radiation Physics (CMRP), University of Wollongong, Australia, have developed the concept of silicon microdosimetry for more than two decades to address the shortcomings of tissue equivalent proportional counter (TEPC) [1]. There has been a remarkable improvement in the performance of the latest microdosimeters (called "mushroom" microdosimeter). This presentation is aimed to update the recent development of silicon on insulator (SOI) microdosimetry and focus on recent results obtained with this microdosimeter for studying radiation shielding properties of materials and angular dependence of the microdosimetric probe in isotropic field of space radiation environments. Astronauts are exposed to high-energy cosmic radiation which may have harmful health effects. At the altitude of the International Space Station (ISS), the main radiation sources are Galactic Cosmic Rays (GCRs), Solar Particle Events (SPEs) and trapped protons of the Van Allen Belts. The radiation field mainly consists of protons, alpha particles and heavy ions with energies up to hundreds of GeV/u. The dose equivalent, H, is a quantity which expresses the probability that exposure to ionizing radiation will cause biological effects. It is obtained by multiplying the dose by the dose average quality factor, Q, of the radiation. (author)