Experimental and numerical evaluation of the performance of an integrated activation device for neutron spectrum confirmation at THOR-BNCT

Experimentally ensuring the quality of neutron beam before patient treatment is a topic of central importance for a boron neutron capture therapy (BNCT) facility. The procedure of beam quality assurance currently adopted at THOR-BNCT lacks a direct indication related to the energy distribution of neutrons. A new device based on multiple activation foils was therefore proposed to provide a quick confirmation of the unchanged neutron spectrum before patient irradiation. The device’s responses to the THOR-BNCT neutron beam are presented. A series of experimental tests were repeated to establish the baseline performance of the device, and further numerical simulations were conducted to determine its sensitivities to various perturbations in the reference spectrum. To increase the rigorousness of beam quality assurance by supplementing additional information about neutron spectrum, the device has been suggested to assist the role of Au/Cu activation foils in the current procedure as and when required.