A portable fast neutron radiography system for non-destructive analysis of composite materials

摘要

Depending on the neutron energy used, neutron radiography can be generally categorized as fast and thermal neutron radiography. Fast neutron radiography (FNR) with neutron energy more than 1 MeV opens up a new range of possibilities for a non-destructive examination when the inspected object is thick or dense. Other traditional techniques, such as X-ray, gamma ray and thermal neutron radiography, do not meet penetration capabilities of FNR in this area. Because of these distinctive features, this technique is used in different industrial applications such as security (cargo investigation for contraband such as narcotics, explosives and illicit drugs), gas/liquid flow and mixing and radiography and tomography of encapsulated heavy shielded low Z compound materials. The FNR images are produced directly during exposure as neutrons create recoil protons, which activate a scintillator screen, allowing images to be collected with a computer-controlled charge-coupled device camera. Finally, the picture can be saved on a computer for image processing. The aim of this research was to set up a portable FNR system and to test it for use in non-destructive testing of different composite materials. Experiments were carried out by using a fast portative neutron generator Thermo Scientific MP 320.