The Thermal Neutron Phase Contrast Imaging Technique

Phase contrast imaging is a bran-new development of neutron radiography. The paper's objective are investigating the theory of neutron phase contrast radiography and exploring the experiment feasibility of SPRR-300 neutron radiography system. Exploring the method of improving the quality for detecting small or thin sample with low mass attenuation coefficient. Accumulating technique experience for developing neutron phase contrast imaging on XXXX.Conventional neutron radiography is based on particle properties, which utilizes various material with different mass attenuation coefficient to obtain investigated sample's inside configuration imaging. So conventional neutron radiography is absorption contrast imaging; but the phase contrast imaging method is based on wave character, when neutron wavefront traverse the investigated sample, the variations of the thickness, material and neutron refractive index of the sample bring different phasic difference. The phasic different causes a change in a shape of a neutron wavefront , the aberrance wavefront interference behind the sample leads to enhancement of the image sharpness.There are three methods of actualizing phase contrast imaging, they are diffraction approach phase contrast imaging , interference approach phase contrast imaging and in-line phase contrast imaging. The imaging quality of Interference approach and diffraction is better, but they have sky-high request for system stability and monochromaticity of neutron source, so they are difficult to be investigated in neutron radiography field. Although the quality of in-line phase contrast imaging isn't very good but it needn't high system stability and monochromaticity of neutron source. The paper introduce diffraction approach phase contrast imaging and interference approach phase contrast imaging briefly. The paper also research the theory and imaging condition of in-line phase contrast imaging detailedly. Considering the advantage of in-line phase contrast imaging, we deem it is the only method of investigate phase contrast imaging on SPRR-300 neutron radiography device.we brought forward a experiment project for neutron phase contrast radiography, which is based on the characteristic of SPRR-300 neutron radiography system. We...