Search

At Budker Institute of Nuclear Physics it was proposed and developed a source of epithermal neutrons based on a tandem accelerator with vacuum insulation and a lithium target for the development of boron neutron capture therapy, a promising method for treating malignant tumors. To measure the "boron" dose due to the boron-lithium reaction, a small-sized detector has been developed. It consists of two polystyrene scintillators, one of which is enriched with boron. Using the detector, the spatial distribution of boron dose and dose of gamma radiation in a 330x330x315 mm water phantom was measured and the results obtained were compared with the results of numerical simulation of the absorbed dose components in such a tissue-equivalent phantom. It is shown that the results obtained are in good agreement with the calculated ones. It was found that the use of a 72 mm Plexiglas moderator provides an acceptable quality of the neutron beam for in vitro and in vivo studies, namely: 1 mA 2.05 MeV proton beam on a lithium target provides a dose rate of 30 Gy-Eq/h in cells containing boron at a concentration of 40 ppm, and 6 Gy-Eq/h in cells without boron. The developed technique for on-line measurement of boron dose and dose of gamma radiation makes it possible to carry out a similar verification of a neutron beam prepared for clinical trials of BNCT after placing a neutron beam shaping assembly with a magnesium fluoride moderator in a bunker adjacent to the accelerator., Proceedings of the 27th Russian Particle Accelerator Conference, RuPAC2021, Alushta, Russia

A promising method of treatment of many malignant tumors is the boron neutron capture therapy (BNCT)*. It provides a selective destruction of tumor cells by prior accumulation of a stable boron-10 isotope inside them and subsequent irradiation with epithermal neutrons. It is expected that accelerator based neutron sources will be created for the clinical practice. One such source could be an original source of epithermal neutrons**, created in BINP. To obtain proton beam a new type of particle accelerator is used - tandem accelerator with vacuum insulation. Generation of neutrons is carried out as a result of the threshold reaction 7Li(p, n)7Be. During 2015-2016 in the construction of tandem accelerator with vacuum insulation several changes were made. This allowed us to suppress the unwanted flow of charged particles in the accelerator, to improve its high-voltage stability, and to increase the proton beam current from 1.6 to 5 mA. Such current value is sufficient for BNCT. The report describes in detail the modernization of the accelerator, presents and discusses the results of experiments on obtaining the proton beam and the formation of neutron flux using lithium target, and declares our prospective plans. The obtained neutron beam meets the requirements of BNCT: the irradiation of cell cultures provides the destruction of cells with boron and preservation of cells without boron. Irradiation of immunodeficient mice with grafted glioblastoma results in their recovery., Proceedings of the 25th Russian Particle Accelerator Conf., RuPAC2016, St. Petersburg, Russia