Performance and experience at neutron radiography facility around Pakistan Research Reactor-I

Neutron radiography facility at PINSTECH has been used for the inspection of couple of test pieces. Thermal neutron flux level has been measured at the object plane. The neutron to gamma ratio at the object plane is greater than 5x 10/sup 4/ n.cm/sup -2/. mR/sup -1/. Cadmium ratio of 18 has been measured experimentally. The collimating ratio is 60. Various constituents of the neutron beam have been measured by exposing beam purity indicator. To determine the sensitivity of the technique and categories the class of the facility, sensitivity indicator has been fabricated and exposed to the thermal neutron beam. All the gaps in the sensitivity indicator are visible. The characterisation of the facility has helped asses the status of the facility for direct neutron radiography. Some modification in the design of the facility are planned to increase the thermal neutron flux level to reduce the exposure time to couple of minutes. (author)