Study of absolute fast neutron dosimetry using CR-39 track detectors

In this work, CR-39 track detectors have extensively been used in the determination of fast neutron fluence-to-dose factor. The registration efficiency, ε, of CR-39 detectors for fast neutrons was calculated using different theoretical approaches according to each mode of neutron interaction with the constituent atoms (H, C and O) of the detector material. The induced proton-recoiled showed the most common interaction among the others. The dependence of ε on both neutron energy and etching time was also studied. In addition, the neutron dose was calculated as a function of neutron energy in the range from 0.5 to 14 MeV using the values of (dE/dX) for each recoil particle in CR-39 detector.Results showed that the values of ε were obviously affected by both neutron energy and etching time where the contribution in ε from proton recoil was the most. The contribution from carbon and oxygen recoils in dose calculation was pronounced due to their higher corresponding values of dE/dX in comparison to those from proton recoils. The present calculated fluence-to-dose factor was in agreement with that either from ICRP no. 74 or from TRS no. 285 of IAEA, which reflected the importance of using CR-39 in absolute fast neutron dosimetry.