Position sensitive neutron detector

In the last several years, the authors have been carrying out the design and manufacutre of the measuring systems for imported position sensitive neutron proportional counters. The detectors for which the authors have worked are one-dimensional 3He position sensitive proportional counters of central resistance wire type. This paper describes on the characteristics, processing circuits and problems of this type of counters. The signal processing circuit of the central resistance wire type detector is of electric charge split type, and the rise time method is also applicable to high resistance wire type detectors. In the charge split type circuit, the result of division which is realized with an analog IC divider shows the value proportional to the position of incidence of particles. Since, in the two-dimensional measurement of position and energy, a computer is used for data processing, the advantages of digital division become dominant. The measured results, anode resistance, the input impedance of a charge sensitive amplifier, and S/N ratio are considered. The positional resolution of 5.6 mm has been obtained for the 2 mm-slit input. The two-dimensional detector can be made by arranging multiple of resistance anode wires. (Wakatsuki, Y.)