Boron-lined ion chambers for reactor applications

Ion chambers for reactor control and safety instrumentation have been indigenously developed. The chambers are used for on-line neutron flux measurement in reactor out-of-core locations. The chambers have a rugged mechanical design with integral mineral insulated cable assembly capable of operating in hostile environment. The electrodes were coated with 350 mg of 92% enriched elemental boron-10 and the theoretically expected neutron sensitivity of 2.9x10 -14 A/nv has been achieved. Tests on one of the chambers show good saturation at 1.0 x 10 8 nv. If necessary, the chamber can be operated at neutron flux of the order of 1.0 x 10 11 nv.