A new position-sensitive nuclear fission counter with a convenient readout method for neutron measurement

Abstract A new position-sensitive nuclear fission counter with an outer diameter of 2.5 cm and a length of 50 cm (100–200 cm is possible) was constructed for the measurement of neutron flux density. One end of a resistive anode rod with a diameter of 5 mm was grounded through a capacitor and the other end was connected to a preamplifier. The counter had a construction with double cylinders. The inner cylinder acting as a cathode with uranium coating on its inner surface was connected to the other preamplifier. Then two preamplifiers were capable of being located at only one end of the counter and, therefore, the insertion of the counter into a narrow measurement-hole in a critical assembly or a nuclear reactor and even in water was possible. The position resolution was about 5 mm.