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A compact accelerator-based neutron source has been proposed and created at the Budker Institute of Nuclear Physics in Novosibirsk, Russia. An original vacuum insulated tandem accelerator (VITA) is used to provide a proton/deuteron beam. As a result of scientific research and modernization, the power of the ion beam was increased, an operation mode without high-voltage breakdowns was achieved, and the operation of the accelerator in a wide range of changes in the energy and current of ions was ensured. The proton/deuteron beam energy can be varied within a range of 0.6-2.3 MeV, keeping a high-energy stability of 0.1%. The beam current can also be varied in a wide range (from 0.3 mA to 10 mA) with high current stability (0.4%). VITA is used to obtain epithermal neutrons for the development of boron neutron capture therapy, thermal neutrons for the determination of impurities in ITER materials by activation analysis method; fast neutrons for radiation testing of materials; 478 keV photons to measure the 7Li(p, p’g)7Li reaction cross section, etc. VITA is planned to be used for boron imaging with monoenergetic neutron beam, for characterizing of neutron detectors designed for fusion studies, for in-depth investigation of the promising 11B(p, alfa)alfa alfa neutronless fusion reaction, for studying the crystal structure of materials by neutron diffraction, etc., Proceedings of the 27th Russian Particle Accelerator Conference, RuPAC2021, Alushta, Russia

For the development of a promising method for the treatment of malignant tumors - boron neutron capture therapy - the accelerator-based epithermal neutron source has been proposed and created in the Budker Institute of Nuclear Physics. After the acceleration phase, a proton beam with an energy of up to 2.3 MeV and a current of up to 10 mA is transported in a high-energy beam line. With a beam size of 1 cm², its power density can reach tens of kW/cm². Diagnostics of the size of such a powerful beam is a nontrivial task aimed at increasing the reliability of the accelerator. The paper presents such diagnostics as: 1) the use of the blister formation boundary during the implantation of protons into the metal; 2) the use of thermocouples inserted into the lithium target; 3) the use of the melting boundary of the lithium layer when it is irradiated with a beam; 4) the use of the activation of the lithium target by protons; 5) the use of video cameras; 6) the use of an infrared camera; 7) the use of the luminescence effect of lithium when it is irradiated with protons; 8) the use of collimators with a small diameter of 1-2 mm; 9) the use of the method of two-dimensional tomography*., Proceedings of the 27th Russian Particle Accelerator Conference, RuPAC2021, Alushta, Russia

Epithermal neutron source based on an electrostatic tandem accelerator of a new type - Vacuum Insulation Tandem Accelerator, and lithium neutron target has been proposed and developed at Budker Institute of Nuclear Physics for Boron Neutron Capture Therapy - promising method for treatment of tumors and for other applications. The paper proposes and implements a flexible and customizable method of operational data processing, allowing researchers to obtain and analyze information directly in the experiment without the need for post-processing data. Its use accelerates the process of obtaining informative data during experimental research and automates the analysis process. Also proposed and implemented a process of automatic distributed journaling of the results of the experiment. As a result of the implementation of the proposed tools increased the productivity of the analysis of experimental data and the detailing of the experimental journal. The developed and implemented system of real-time data processing has shown its effectiveness and has become an integral part of the control system, data collection and data storage of the epithermal neutron source., Proceedings of the 27th Russian Particle Accelerator Conference, RuPAC2021, Alushta, Russia

A vacuum-insulated tandem accelerator was used to observe in situ blistering during 2-MeV proton irradiation of metallic samples to a fluence of up to 6.7 10²⁰ cm². Samples consisting of copper of different purity, tantalum, and tantalum-copper compounds were placed on the proton beam path and forced to cool. The surface state of the samples was observed using a CCD camera with a remote microscope. Thermistors, a pyrometer, and an infrared camera were applied to measure the temperature of the samples during irradiation. After irradiation, the samples were analyzed on an X-ray diffractometer, laser and electron microscopes. The present study describes the experiment, presents the results obtained and notes their relevance and significance in the development of a lithium target for an accelerator-based neutron source, for use in boron neutron capture therapy of cancer., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

A source of epithermal neutrons based on a vacuum-insulated tandem accelerator and a lithium target is developed for the technique of boron neutron capture therapy. A stationary proton beam of 2 MeV with a current of up to 5 mA was obtained in the accelerator. Neutron generation was performed and the flux and neutron spectrum were experimentally measured. A Beam Shaping Assembly was developed and manufactured, which makes it possible to form a therapeutic beam of neutrons to the greatest extent satisfying the requirements of BNCT. It was established that neutron irradiation of tumor cells of human glioma U251 and human glioblastoma T98G, previously incubated in a medium with boron, led to a significant suppression of their viability. Irradiation of mice with grafted human glioblastoma tumor led to their complete cure. In order to increase the beam parameters, the facility was equipped with a wire scanner OWS-30 (D-Pace, Canada; under the license of TRIUMF), a non-contact current sensor NPTC (Bergos, France), a FLIR T650SC infrared camera, an Optris CT Laser 3ML SF pyrometer (Optris, GmbH, Germany), cooled diaphragms with thermistors, telescopic beam receivers with thermoresistors, a new bushing insulator. Two new sources of negative hydrogen ions with a high current are being prepared, one of them is surface-plasma, the other is voluminous. The investigations established the effect of space charge and spherical aberration of lens on the ion beam transport, the dependence of the heating of the diaphragms of the electrodes and the size of the proton beam on the current of the injected beam of negative hydrogen ions and the pressure of the residual gas in the transport channel. The report describes the modernization of the accelerator, discusses the results of research, declares plans., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

In the BINP SB RAS was proposed and created a source of epithermal neutrons for BNCT. The proton beam is obtained on a tandem accelerator with vacuum insulation. Sectionalized demountable feed through insulator is an integral part of the accelerator. Voltage from the high voltage source is distributed to the electrodes via resistive divider. Because of the small amount of current (hundreds of microamperes) flowing through the divider, dark currents that occur in the accelerating gaps, can significantly affect the uniform distribution of the potential along the accelerating channel, and, consequently, on the beam transportation. Therefore there is a need to change the design of the feed through insulator which will allow to set potentials at the electrodes directly from the high voltage rectifier sections. To study the feasibility of such changes has been designed and built an experimental stand, in which a single insulator with double height subjected to the same conditions as in accelerator. On the experimental stand was studied electrical strength of ceramic and polycarbonate insulators with a different shape of the surface. The paper presents the results of experimental studies of insulators. Their application will get rid of the voltage divider inside the feed through insulator and realize the scheme which allows to set potential on the electrode gaps directly from the rectifier section. This will increase the operating voltage of the accelerator and its reliability., Proceedings of the 25th Russian Particle Accelerator Conf., RuPAC2016, St. Petersburg, Russia

In BINP the neutron source for BNCT based on proton accelerator was designed and built. It is necessary for the therapy to ensure a stable proton beam current of not less than 3 mA with energy 2 MeV. During the injection of negative hydrogen ion beam into the accelerator the unwanted charged particles are produced, affecting the stability of beam parameters. The article describes meth-ods of suppression of undesirable charged particles and the results of experiments., Proceedings of the 25th Russian Particle Accelerator Conf., RuPAC2016, St. Petersburg, Russia

In The Budker Institute of Nuclear Physics the accelerator-based source of epithermal neutrons was invented and now operates to be used in the boron neutron capture therapy. For several reasons the real beam flow in the facility differs from the calculated one. To take into account this distinction it is necessary to provide continuous monitoring of the beam parameters. In order to optimize the facility operation the beam should be followed not only during the formation but also while an acceleration takes place and the proton beam is thrown on the lithium target as the proton current and energy influence on the neutron output. In this way it seems to be a significant issue to measure the current, profile and also the position of the ion beam in a low-energy part of the accelerator. This work represents the results of experiments with the D-Pace WS-30 Wire Scanner Probe, which was installed in the low-energy part of the accelerator. The experiments were carried out under various conditions to vary the position and focusing control via the system of magnetic correcting elements. To correctly interpret experimental data it was necessary to take into account physical phenomena which occur during an experiment. In this way the effects which take place when the probe interacts with the beam were thoroughly considered. The obtained results allowed to restore the ion beam profile, define its size and position., Proceedings of the 25th Russian Particle Accelerator Conf., RuPAC2016, St. Petersburg, Russia

The new source of epithermal neutrons*, designed for boron neutron capture therapy (BNCT)** of cancer in oncology clinic, was proposed and developed in Budker Institute of Nuclear Physics. This method of treatment is effective against several currently incurable radioresistant tumors, such as brain glioblastoma and melanoma metastases. The neutron source includes a new type of accelerator: accelerator-tandem with vacuum insulation, lithium neutron generating target and neutron beam shaping assembly. Current accelerator produces a stationary 5 mA proton beam with 2 MeV energy, but this is not sufficient for therapy on humans. For conducting the experiment on humans it is necessary to create a new power rack for the ion source. The report summarizes results of the development and implementation of new power rack, with remote control and data collection systems, to reach 15 mA beam current. This system will increase the proton beam current and, as a result, the neutron yield, that is needed to heal people., Proceedings of the 25th Russian Particle Accelerator Conf., RuPAC2016, St. Petersburg, 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