Time-spatial neutron measurement by using position-sensitive He-3 proportional counter

Time-spatial neutron measurement was carried out by using a position-sensit ive He-3 proportional counter (PSPC) in the Kyoto University Critical Assem bly. The data of the output pulses from the PSPC were acquired by a data ac quisition system which was based on the LN-9000 system of Laboratory Equipm ent Corporation. In this system, the time and the position data of the neut ron detection pulses were simultaneously accumulated by a personal computer . In the present study, the Rossi-alpha method, which was derived for time- domain neutron correlation analysis? was extended in order to process the m easured two-dimensional data of time and space. The processed experimental results and a theoretical formula based on the one-group diffusion approxim ation neglecting the higher modes agreed well with each other, which indica tes the present system is applicable for reactor physics experiments includ ing reactor kinetics. (C) 1999 Elsevier Science B.V. All rights reserved.