A Fast Neutron Radiography System Using a High Yield Portable DT Neutron Source

Resolution measurements were made using 14.1 MeV neutrons from a high-yield, portable DT neutron generator and a neutron camera based on a scintillation screen viewed by a digital camera. Resolution measurements were made using a custom-built, plastic, USAF-1951 resolution chart, of dimensions 125 × 98 × 25.4 mm3, and by calculating the modulation transfer function from the edge-spread function from edges of plastic and steel objects. A portable neutron generator with a yield of 3 × 109 n/s (DT) and a spot size of 1.5 mm was used to irradiate the object with neutrons for 10 min. The neutron camera, based on a 6LiF/ZnS:Cu-doped polypropylene scintillation screen and digital camera was placed at a distance of 140 cm, and produced an image with a spatial resolution of 0.35 cycles per millimeter.

Preliminary Study on Improving Resolution of D-T Neutron Radiography based on Associated Alpha and Coded Source Imaging Methods

Limitations of fast neutron radiography include low detection efficiency and poor spatial resolution. D-T neutron radiography is one compact fast neutron radiography method. Based on D-T associated alpha particle method and coded source imaging method, we indicate one new method to improve resolution of D-T neutron radiography. This method could get distribution of D-T neutrons by detecting alpha particles. Without real coded mask, the D-T radiography structure is considered as coded source imaging of fast neutrons. With reconstruction method, the real object could be reconstructed from projections. One prospect setup of D-T associated alpha neutron source has been carried out with Monte-Carlo simulation. The projection images of two different situations are collected and reconstruction results show that it’s possible to improve image quality of D-T neutron radiography.

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

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 FN R 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.