2007 Volume 56 Issue 8 Pages 431-435
A position sensitive proportional counter based on the tilted wire position reading method was examined with a view to the position dependency of detection efficiency for thermal neutrons, and was applied to the measurement of the thermal neutron space distribution at a neutron-guide channel, with a collimator of 5 cm diameter, of Kinki University Reactor (UTR-KINKI) . The counter consisted of a pair of position-sensing wires extended in parallel each other but tilted against the anode wire. The effective detection length of the counter was about 6 cm, and sintered boron nitride was employed as neutron converter in order to obtain uniform thickness of boron layer. The result showed that the constant detection efficiency was realized in about 4 cm center region of the counter. The thermal neutron space distribution was found to have a flat top part of about 2 cm diameter.