The Measurement of the Neutron Yield of the 7Li(p,n)7Be Reaction in Lithium Targets

Abstract

A compact accelerator-based neutron source has been proposed and created at the Budker Institute of Nuclear Physics in Novosibirsk, Russia. An original design tandem accelerator is used to provide a proton beam. The neutron flux is generated as a result of the 7Li(p,n)7Be threshold reaction using the solid lithium target. A beam shaping assembly is applied to convert this flux into a beam of epithermal neutrons with characteristics suitable for BNCT. The BNCT technique is being tested in in vitro and in vivo studies, and dosimetry methods are being developed. Currently, the BNCT technique has entered into clinical practice in the world: after successful clinical trials, two clinics in Japan began treating patients, and four more BNCT clinics are ready to start operating. The neutron source proposed at the Budker Institute of Nuclear Physics served as a prototype for a facility created for a clinic in Xiamen (China). It is planned to equip the National Medical Research Center of Oncology (Moscow, Russia) and National Oncological Hadron Therapy Center (Pavia, Italy) with the same neutron sources. Due to the impending use of an accelerator neutron source for treating patients, the validation of the neutron yield of the 7Li(p,n)7Be reaction in lithium metal targets is required. The theoretical neutron yield has not been evaluated experimentally so far.

In Vivo Accelerator-Based Boron Neutron Capture Therapy for Spontaneous Tumors in Large Animals: Case Series

“…Epithermal neutron irradiation was carried out at the Budker Institute of Nuclear Physics in Novosibirsk, Russian Federation using the Vacuum Insulated Tandem Accelerator (VITA) neutron source with a lithium neutron-producing target [ 79 , 80 , 81 , 82 ]. The neutron-beam shaping assembly and detailed characteristics of the beam, including the neutron spectra, fast neutron, and photon components are described in previous reports [ 83 , 84 , 85 , 86 , 87 ].…”

“…Neutron fluence calculations based on Lee et al (1999) [ 90 ]. The actual neutron fluence corresponds to the calculated one [ 82 ].…”

Dose-Dependent Suppression of Human Glioblastoma Xenograft Growth by Accelerator-Based Boron Neutron Capture Therapy with Simultaneous Use of Two Boron-Containing Compounds

“…The animals were irradiated at the source of epithermal neutrons, which included an electrostatic tandem accelerator with vacuum insulation [ 18 , 20 ], a lithium neutron-generating target (reaction 7 Li(p,n) 7 Be) [ 21 , 45 ], and a neutron-beam shaping assembly [ 21 , 46 ]. The characteristics of the neutron beam and its contamination by fast neutrons and photons have been described previously [ 47 , 48 ].…”

Experimental validation of proton boron capture therapy for glioma cells

“…According to the early clinical studies, BNCT has the potential to become effective as a targeted therapy 10 . Being initially limited by the need of usage of research nuclear reactors as the neutron source, nowadays BNCT approach is boosted by the availability of specialized compact neutron source specially designed for medical purposes 11 Several investigations are under way for the use of BNCT in high grade glioma treatment 12,13 . One of the critical components for successful deployment of BNCT is the choice of compounds for 10 B delivery to the tumor that would meet the requirements for high tumor uptake, low normal tissue uptake, low toxicity and rapid clearance after treatment [14][15][16] .…”

“…Proton boron capture therapy (PBCT) was proposed as a potential cancer treatment method a few decades ago. In PBCT the dose enhancement effect was assigned to the reaction of nuclear fusion between 11 B nuclei and the incident beam protons ( 11 B + p → 8 Be + α → 3α + 8.7 MeV). Emission of the high Linear Energy Transfer (LET) α-particles by proton-boron fusion reaction, that occurs primarily in the Bragg peak region and causes irreparable clustered DNA damages, was expected to increase the effectiveness of destruction of the tumor cell.…”