Measurement of Neutron Parameters in the Treatment Beamof In-Hospital Neutron Irradiator

Abstract

In order to verify the design specifications of in-hospital neutron irradiator (IHNI), the neutron fluence rates at the exit of its thermal and epithermal neutron beams were measured by using the method of cadmium difference. The radial distribution of the different components of the treatment beam exit was measured using a scanning device with a diamond detection unit. The results show that the thermal neutron fluence rates are 1.75×109 cm-2·s-1 and 6.57×107 cm-2·s-1 at the center of the thermal and epithermal neutron beams, respectively, and the epithermal neutron fluence rates are 1.41×107 cm-2·s-1 and 3.14×108 cm-2·s-1 at 30 kW full power operation; The vast majority of the treatment beam components are distributed within the beam aperture, with an exponential drop-off near the beam edges. The measurement results provide parameter support for subsequent related testing and experiments of In-Hospital Neutron Irradiators.

Keywords

• thermal neutron fluence rate
• boron neutron capture therapy
• activation method
• radial distribution