| 摘要 |
PURPOSE:To prevent any deterioration of measurement accuracy by attaching a coaxial cable, one end of which opens into an airtight case and the other end is sealed with ceramic, to an airtight case in which an outer electrode having a nuclear fission substance and an inner electrode are installed. CONSTITUTION:When constituting a nuclear-fission-type ionization chamber used as the detector of a local output area neutron detection assembly for measuring neutrons in an atomic furnace for power supply, firstly, a columnar inner electrode 4 is installed inside an outer electrode 2, formed by packing a nuclear fission substance 3 in an air-tight case 1, with a space 5 allowed between the electrodes 2 and 4. Next, the space 5 is packed with argon. At the same time, a coaxial cable 6 is attached to the case 1 to achieve electric conduction; one end 6a of the cable 6 opens into the case 1, the outer end of the cable 6 is sealed with a ceramic member 9 and the internal area of the cable 6 is packed with an insulating material 12. Because of the above constitution, since ceramic does not exist in the end 6a, measurement accuracy can be improved without influencing the pressure of argon gas in the case 1. |
