Primena detektora CR-39 u detekciji i dozimetriji neutrona

Abstract

A comparison of experimental and calculated responses of a CR-39 detector to neutron spectra from an Am–Be source is presented in this paper. A computer program called Neutron_CR-39.F90 for neutron simulation through a CR-39 detector and its detection was described and developed. The secondary particles are created in different directions and their latent tracks are oriented randomly within the detector. Some tracks will be etched from the point where the particle was created in the direction of the particle motion – this is direct etching. Other tracks will be etched from the point where the particle was stopped or from where it exited from the detector, in an opposite direction to the particle movement – this is the etching in a reverse direction. In this paper a calculation of the track walls etched in the same and opposite directions is described by using Newton’s method. The program Neutron_CR-39.F90 contains subroutine Neutron.f90 for neutron simulation and subroutines Trackfdmsame.f90 and Trackfdmback.f90 for the calculation of created track profiles after detector etching in the same and reverse direction, respectively. Developed program has been used to calculate the neutron dose equivalent rate for the CR-39 detector as well as the track density. Conversion coefficient (sensitivity) between track density in track/cm2 and neutron dose equivalent in mSv, was calculated by using above mentioned program. It has been found that sensitivity increases linearly with removed layer in the investigated range between 6 mm and 24 mm. The neutron equivalent dose rate was measured by an active device, and compared with the calculated one. Good agreement was found between these two independent techniques for equivalent dose determination. The mean neutron fluence to dose equivalent conversion factor, hφ, was determined also, and it is in good agreement with previously published results (Burger and Schwaster, 1988; ISO/DIS 8529, 2000). Experimental and theoretical results, and their agreement, suggest the potentiality of a CR-39 detector for fast neutron dosimetry.