Characterization of a novel large area microdosimeter system for low dose rate radiation environments

A feasibility study is presented on a newly developed microdosimetry system named Octobox, for its application in low dose rate, mixed radiation environments. A full characterization of the device was performed at the Heavy Ion Medical Accelerator in Chiba (HIMAC), Japan, out-of-field of various heavy ion radiation fields - 290 MeV/u C-12, 230 MeV/u and 490 MeV/u Si-28 and 400 MeV/u Ne-20 ions, as well as a low dose rate Rn-222 environment at the Australian Nuclear Sciences and Technology Organization (ANSTO). The device was shown to collect adequate statistics in a short period of time when compared to the MicroPlus probe with a single microdosimeter, while accurately measuring microdosimetric quantities and the corresponding average quality factor ((Q) over bar) and dose equivalent (H) of the mixed radiation field. Good agreement of the microdosimetric spectra was also shown with Geant4 simulations for all presented ion fields. Based on the findings in this study, the Octobox is capable of being applied in mixed, low dose rate, radiation environments such as those encountered in space and aviation, as well as in underground mines for radiation protection purposes.

Automated summary

The feasibility of the newly developed microdosimetry system Octobox for application in low dose rate, mixed radiation environments was assessed through a characterization study at HIMAC in Japan and ANSTO in Australia. The device demonstrated efficient data collection, accurate measurement of microdosimetric quantities, and good agreement with Geant4 simulations for various ion fields. The findings suggest Octobox could be used effectively in mixed, low dose rate radiation environments for radiation protection in space, aviation, and underground mines.