Utilization of Low Voltage D-T Neutron Generators in Neutron Physics Studies

Abstract: In a small nuclear laboratory of a developing country a low voltage D-T neutron generator can be a very useful scientific apparatus. Such machines have been used successfully for more than 40 years in teaching and scientific research. This thesis is a description of contributions by the author to make a few more additions to their existing variety of applications.

The original continuous mode 150-kV D-T neutron generator has been modified to have also a capability of producing 2-ns pulsed neutrons. Together with a carefully designed 10 m long flight path collimator and shielding of a 25 cmØ x 10 cm thick BC-501 neutron detector, the pulsing system was successfully used for measuring the double differential cross-section (DDX) of natural iron for 14.1-MeV neutron from the angle of 30 deg to 150 deg in 10 deg steps.

In order to extend the utility of the generator, two methods for converting the almost monoenergetic 14-MeV neutrons to monoenergetic neutrons of lower energy were proposed and tested. Both designs used the neutron-proton interaction at a circular surface-of-revolution made of hydrocarbon materials. The first design is for a pulsed neutron generator and the second design is for an ordinary continuous mode generator. The latter method was successfully used to measure the scintillation light output of a 1.4 cmØ spherical NE-213 scintillation detector.