Simultaneous monitoring system of thermal neutron flux for boron-neutron capture therapy

A simultaneous monitoring device of neutron flux for boron-neutron capture therapy has been developed. A silicon surface-barrier detector mounted with borax is used to count neutrons. The silicon detector is 2.5 mm in diameter and is attached to a cable 1.6 mm in diameter and about 1 m in length. The relative error of the linearity between the counting rate and the neutron flux is within 5%, including statistical fluctuations. The relative error of counting rate is within 5% during 240 min of irradiation with a constant neutron flux of 1.7 x 109 n/cm2 sec