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Abstract
Neutron Radiography (NR) is a powerful Non Destructive Testing (NOT) technique in viewing the internal details of objectives and components. The advantages of neutron radiography over other non destructive testing techniques is that neutron radiography can provide, in some cases, full detailed infonnation that cannot be obtained by any other traditional techniques such as x-ray or gamma ray radiography. The image fonnation by neutron radiography can be degraded by many factors, the most important of which is scattering blur from the sample itself.
Previous attempts were made to correct scattering effects on neutron radiography using computer software. In this thesis experimental work was carried out to enhance the image quality and increase the ERIT-2 neutron radiography facility sensitivity by scattered thennal neutron deblurring, using two different techniques. The first technique is image enhancement using multilayer converter screens. The second technique is image debh,lrringusing an anti scatter grid. The Mont Carlo N-ParticIe (MCNP) cod c~ilculations were used to detennine the best image fonnation from the multilayer converter screens technique. The code was also used in the design of the anti scatter grid dimensions and t~ find the fraction of thennal scattered neutrons removed by the grid.
The experimental work done shows clearly that using either technique will produce an image with quality that is much better than that without using any deblurring technique. The experimental results from the two techniques were compared to each other to detennine the powerful technique adequate to its radiographic samples. In this work the best image fonnation from different converter screen numbers was analyzed and compared with MCNPcalculations to detennine the maximum scattered thennal neutrons elimination from different samples. The calculations indicate that most of scattered thennal neutrons are removed after two layers of indium (In) converter screen of total thickness 1 rom. five samples with different atomic numbers were radiographed with the enhanced techniques. The results indicate that antiscatter grid is powerful for imaging enhancement of the radiographed material of light atomic number, while multilayer converter screens technique is powerful for imaging enhancement for material of higher atomic number.