Results of measurements on shuttle missions to the ISS of the neutron component of the radiation field

For the etch regime employed, the combination of high LET threshold (there is little response below a restricted LET200 in PADC of 30-40 keV/μm) and poor angle dependence of response to high-energy charged particles results in a much reduced overall response of the neutron dosemeter to the HZE component of the field in spacecraft and no response to protons of energy greater than about 1 MeV. A correction of 10-20% is necessary to account for the detector HZE response. Alternatively, an additional chemical etch can be carried out which allows discrimination.