Optimized beam shaping assembly for a 2.1‑MeV proton‑accelerator‑based neutron source for boron neutron capture therapy

Boron Neutron Capture Therapy (BNCT) is facing a new era where diferent projects based on accelerators instead of reactors are under development. The new facilities can be placed at hospitals and will increase the number of clinical trials. The therapeutic efect of BNCT can be improved if a optimized epithermal neutron spectrum is obtained, for which the beam shape assembly is a key ingredient. In this paper we propose an optimal beam shaping assembly suited for an afordable low energy accelerator. The beam obtained with the device proposed accomplishes all the IAEA recommendations for proton energies between 2.0 and 2.1 MeV. In addition, there is an overall improvement of the fgures of merit with respect to BNCT facilities and previous proposals of new accelerator-based facilities.Junta de Andalucía (Andalusian Regional Government, Programa Operativo FEDER Andalucia 2014–2020 under contract A-FQM-371-UGR18)University Chair “Neutrons for Medicine”: Spanish Fundación ACS, Capitán Antonio, La Kuadrilla de Iznalloz and Sonriendo se Puede GanarSpanish Ministry of Science, Innovation and Universities - FPU grant FPU17/0230