Abstract-A novel silicon-on-insulator microdosimeter for estimating the radiobiological effectiveness (RBE) of a mixed radiation field is presented. An ion beam induced charge collection study has confirmed the microdosimeter possesses well defined micron sized 3D cylindrical sensitive volumes. An array of these SVs has the capability of studying the track structure of high energy heavy ions typical of a deep space environment.

A Silicon On Insulator (SOl) Microdosimeter and a PIN diode response was tested in the TSL quasimonoenergetic neutron field at Uppsala university. The response of the SOl Microdosimeter and PIN diode to the field was also simulated using GEANT4 for comparison with the experimental measurements. Angular response of the PIN diode with respect to the beam was also measured.