Optimisation of resolution in accelerator-based fast neutron radiography

• Published in: NUCL INSTRUM METHODS PHYS RES SECT A Vol. 477; no. 1; pp. 378 - 382
• Main Authors: Rahmanian, H., Ambrosi, R.M., Watterson, J.I.W.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Elsevier B.V 21.01.2002
• Subjects: Detectability; Fast neutron; Geometry; Monte Carlo methods; Neutron scattering; Optimization; Phosphors; Ray tracing; Scattering; Scintillator; Signal to noise ratio; Geometry; 81.70; Scintillator; Scattering; Detectability; 02.50.N; Fast neutron; 29.40.M; 42.15.D
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/S0168-9002(01)01834-4

In fast neutron radiography, imaging geometry, neutron scattering, the fast neutron scintillator and the position-sensitive detector all influence feature contrast, resolution and the signal-to-noise ratio in the image. The effect of imaging geometry can be explored by using a ray-tracing method. This requires following the path of neutrons through the imaging field, which includes the sample of interest. A relationship between imaging geometry and feature detectability can be developed. Monte Carlo methods can be used to explore the effect of neutron scattering on the results obtained with the ray-tracing technique. Fast neutrons are detected indirectly via neutron–nucleon scattering reactions. Using hydrogen-rich scintillators and relying on the recoil protons to ionise the scintillator material is the most sensitive technique available. The efficiency, geometry and composition of these scintillators influence the detectability of features in fast neutron radiography. These scintillator properties have a direct bearing on the specifications of the position-sensitive detector chosen to detect the light emitted.