Calibration and simulation of a silicon dosemeter for ambient dose equivalent in low-earth orbit space.

A particle dosemeter (PD) is a payload of NEXTSat-2 in the low-earth orbit (LEO). The absorbed dose in LEO needs to be converted into the ambient dose equivalent (H*(10)). Due to a mixed field in LEO, the calibration factors (klow and khigh) should be determined for the low-and high-linear energy transfers (LET) (below and above 1.5 keV/μm), respectively. The PD was irradiated with a 137Cs source at the Korea Radiation Solution facility to obtain H*(10) and absorbed doses. However due to the lack of sources for the high-LET calibration, H*(10) and an absorbed dose were calculated by simulating PD for the high-energy neutron field at CERN-EU high-energy Reference Field. The measured klow of PD had a difference of 5.1% and 9.5% from the calculated value of PD and the measured value of Liulin detectors, respectively. However, a difference in khigh between PD and Liulin was explained by the contribution of non-neutron components to Liulin in the measurements.