PRELIMINARY EXPERIMENTS OF FAST NEUTRON RADIOGRAPHY WITH D-Be REACTION

Abstract

The D-Be reaction was investigated with a 4.5 MV Van de Graaff accelerator and a 600 kV Cockcroft-Walton accelerator. Fast neutron yields were measured for deuteron beams with energy from 200 keV to 3 MeV bombarding a thick beryllium target. Also angular distributions for emitted neutrons were measured at several deuteron energies. Fast neutron radiography was carried out with simple samples at the 4.5 MV Van de Graaff accelerator. The preliminary experiment results indicate that the D-Be reaction at lower deuteron energies can be used for fast neutron radiography, if the gamma rays are sufficiently shielded.

Neutron Yields of Thick Be Target Bombarded with Low Energy Deuterons

“…The neutron yields were measured on two facilities [10][11]. The yield data for D + energies of 1 MeV -3 MeV were measured on 4.5 MV Van de Graaff (VDG) at Peking University.…”

Preliminary Study on Neutron Radiography with Several Hundred keV Fast Neutrons

“…The neutron imaging facility based at Peking University has a 4.5 MV Van de Graaff accelerator which has provided many encouraging results in thermal and fast neutron radiography, [7] fast neutron resonance radiography, [8] and fast neutron radiography converter development. [9] In this work, a proper nuclear reaction is chosen to generate several hundred keV fast neutrons.…”

“…The 7 Li(p,n) 7 Be reaction can produce several hundred keV neutrons with a proper incident proton energy and its neutron yield is high. A LiF target is used because it is stable and easy to handle.…”

“…where 𝐸 p (𝑥) is the incident proton energy, 𝜃 is the neutron emission angle, 𝐼 p is the proton fluence, 𝜎(𝐸 p (𝑥), 𝜃) is the double differential cross section for 7 Li(p,n) 7 Be, Ω is the solid angle of imaging area, and 𝑥 is the depth of the proton penetrating in the target. The cross section data used in this work was taken from the literature.…”