Neutron field mapping and dosimetry by CR-39 for radiography and other applications

A neutron telescope based on the n–p elastic scattering on H is suggested to investigate the inhomogeneity of neutron fields used for different applications like neutron radiography, biological investigations or dosimetry where the number of neutrons with high energy (above 8 MeV) is negligible. The telescope consists of a thin polyethylene foil and a track etch detector divided by an air gap and placed inside a glass tube which can be evacuated by a simple vacuum pump. The angular and energy resolution of the telescope mostly depend on the diameter of the tube, the length and pressure of the air gap, on the thickness and H content of the radiator and on the type of the track detector. The response of the telescope is characterized by several parameters: the incident angle distribution of protons, the length and the minor diameter distributions of the etched tracks. The response was calculated for several assemblies by a Monte Carlo code and based on the results, three different experimental telescopes were constructed and tested. The most suitable one was selected for routine measurements.