Simulated response of a multi-element thick gas electron multiplier-based microdosimeter to high energy neutrons.

The response of a microdosimeter for neutrons above 14 MeV is investigated. The mean quality factors and dose-equivalents are determined using lineal energy distributions calculated by Monte Carlo simulations (Geant4 toolkit). From 14 MeV to 5 GeV, the mean quality factors were found to vary between 6.00 and 9.30 and the dose-equivalents were in agreement with the true ambient dose-equivalent at the depth of 10 mm inside the ICRU sphere, H(10). An energy-independent dose-equivalent response around a median value of 0.86 within 22% uncertainty was obtained. Therefore, the microdosimeter is appropriate for dose-equivalent measurement of high-energy neutrons.