Microdosimetry with GEMTEQ, a novel microdosimeter

This paper presents the first microdosimetric measurements with the GEMTEQ detector and a comparison with a more conventional Multi-Element Tissue Equivalent Proportional Counter (METEPC, [1]) operated with a mean chord length of 1 μm and a FLUKA simulation. Conventional TEPCs are based on operation at low pressures such that the mean chord length in their active gas volume is equivalent to typically one or two micrometres in tissue. However, the GEMTEQ is a small gaseous detector based on the GEMPix detector [2], operated with tissue-equivalent gas at standard pressure. Microdosimetric measurements are possible due to the high granularity of the readout. Measurements were performed at the mixed-field irradiation laboratory at the Faculty of Energy Systems and Nuclear Science, Ontario Tech, Canada, with 2.5 MeV neutrons, 65 keV (peak) X-rays and a Cs-137 source (here only results for neutrons are presented). (author)