Pressurized ion chamber for low energy radiation monitoring

Ion chambers that can respond to gamma energies as low as 35 keV have been developed for environmental and area monitoring for low energy X-ray background a: the rotating anode X-ray generator facility and other accelerators at CAT, Indore. They are expected to measure exposure levels ranging from 10 mu r/h to 100 mr/h. These chambers have an all-welded aluminium construction and pressurized nitrogen filling. Explosion welded SS-AI clad material has been used for the welding of SS-to-alumina insulators. Out of the two ion chambers developed. the environmental ion chamber has a 25 1 sensitive volume filled at 85 psi and detects radiation exposure levels from 10 mu r/h to 10 mr/h. The 800 cc area monitor ion chamber filled at 120 psi can be used from 10 mr/h to 10 r/h with a portable survey instrument. These chambers have an energy response between 35 keV and 1.25 MeV that is uniform within +/-9%. (C) 1997 Elsevier Science Ltd.