Response of passive detectors to high-energy neutrons

The response of plastic nuclear track detectors and several types of thermoluminescent detectors (TLD) to 66 and 100 MeV energy neutrons was investigated. Combinations of such detectors are frequently used to determine the dosimetric characteristics in various mixed radiation fields, e.g. onboard the International Space Station, where high-energy neutrons can be expected. The response of the TLDs was very low, sometimes at the background level. When used in mixed radiation fields, the TL signal induced by neutrons several tens/hundreds of MeV energy was actually negligible. No significant differences between 66 and 100 MeV were observed in the response of the plastic nuclear track detectors. The linear energy transfer particles below 100 keV/μm (mainly recoil protons) contribute about one-half to the absorbed dose and dose equivalent. (orig.)