Validation and optimization of the epithermal neutron flux detector using the 71Ga(n,γ)72Ga reaction

Abstract

An intense epithermal neutron flux is necessary for boron neutron capture therapy (BNCT), a promising technique for the treatment of malignant tumors. The epithermal neutron flux is an essential characteristic of the BNCT neutron beam and its measurement is directly related to the reliability of the treatment planning system. Such a tool could be a cylindrical activation detector using 71Ga(n,γ)72Ga reaction. This paper describes a detector made in the likeness of the previously proposed one and presents the results of numerical simulation of the detector sensitivity and its experimental use. The paper notes the difference between the simulated sensitivity of the detector and the sensitivity of the previously proposed one and makes assumptions about the reason for this difference. The work also proposes an improvement of the detector, which allows not only to reduce the contribution of fast neutrons to the detector sensitivity, but also to provide a new opportunity to refine the spectrum of neutrons that are most effective for the treatment of deep-seated tumors.