Measurement of accelerator-based neutron distributions using nuclear trackdetectors

Nuclear track detectors were used to measure the longitudinal and transvers e distributions of slow neutrons in a moderated neutron held as well as the longitudinal and transverse distributions of fast neutrons produced on the 0 degrees beam line of the KFUPM 350 keV ion accelerator. The neutrons wer e first produced from the T(d,n)He-4 reaction with a neutron energy of appr oximately 14 MeV and were then moderated in a cylindrical polyethylene mode rator placed at the end of the 0 degrees beam line. The optimal transverse slow neutron distribution was found to be uniform within +/-4.5% at a 3 cm depth inside the moderator. The fast neutron distribution component along t he moderator central axis exhibited an exponential-like drop in intensity w ith depth. Linearity checks of alpha and proton recoil track density with i rradiation time for the nuclear track detectors were verified for both slow and fast neutrons. (C) 2000 Elsevier Science B.V. All rights reserved.