Neutron radiographic facilities using isotopic neutron source particularly Cf-252 are being developed world wide to extend the foreseeable advantages of this techniques to more areas of interest and make facilities available for inplant use. This laboratory has designed, developed, fabricated and installed one such facility.

The image quality obtained in thermal neutron radiography is mostly dependent on beam parameters like thermal neutron content (Nc), L/D ratio, n/r ratio etc. these parameters can be varied by changing some of the design parameters of isotope based neutron radiography facility.

Moreover change in one parameter is associated with change in other parameter. Hence, detailed studies covering these aspects and its ultimate effect on neutron radiographic image needs to be established, specially for isotope based facilities, for which these parameters are of significant importance due to its low flux problems.

The paper brings out of the details of methodologies and results of the experiments done towards this aim.