Radiography and capture gamma ray facility for californium-252

A californium-252 neutron source facility was designed and fabricated which could be used for thermal neutron radiography and capture gamma ray analysis and would have the following characteristics: (1) be usable as a type A transfer cask, (2) be semi-portable as an analysis facility, (3) be operable in either a horizontal or vertical beam port orientation, (4) be relatively compact, and (5) be economically priced. The resulting 3600-lb unit was a 36 in. by 40 in. high steel drum filled with a polyester resin extended with water and an antifreeze solution, doped with 2 mg/cm3 boron-10 and 5 vol. percent lead. With the addition of boron, the 2223 keV hydrogen capture gamma ray contribution was reduced by greater than 70 percent. The lead addition further reduced the gamma ray intensity by greater than 80 percent. A 6-in. polyvinyl chloride pipe is concentric with the cylinder axis and extends the length of the shield, allowing diverse possibilities for beam extraction and collimation. (U.S.)