S. Yu. Taskaev

First experiments on neutron detection on the accelerator-based source for boron neutron capture therapy

A pilot accelerator-based source of epithermal neutrons, which is intended for wide application in clinics for boron neutron capture therapy, has been constructed at the Budker Institute of Nuclear Physics (Novosibirsk). A stationary proton beam has been obtained and near-threshold neutron generation regime has been realized. Results of the first experiments on neutron generation using the proposed source are described.

Recording of Current Accompanying an Ion Beam in a Tandem Accelerator with Vacuum Insulation

A proton beam (2 MeV and 1.6 mA) has been obtained on a tandem accelerator with vacuum insulation. Experimental results are given that outline the reasons for current limits, and approaches to increasing the current of a proton beam are proposed.

Measuring the lithium layer thickness

An epithermal neutron source based on a compact tandem accelerator is being built at the Budker Institute of Nuclear Physics for use in neutron capture therapy at a cancer clinic. It is expected that a lithium neutron-generating target will act as a neutron source. An original technique for determining the thickness of the lithium layer is proposed, and the measured radial distribution of the evaporated lithium layer thickness is presented.

A voltage buildup at high-voltage vacuum gaps of a tandem accelerator with vacuum insulation

A new type of accelerator, namely, an electrostatic tandem accelerator with vacuum insulation, being distinguished by a high acceleration rate of charged particles and a large surface area of accelerating electrodes, was proposed, manufactured, and put into operation to obtain a proton beam with a 2-MeV energy and a direct current up to 10 mA. The influence of breakdowns on the electric strength of high-voltage components of the accelerator is studied in the work.

Beam of monoenergetic neutrons for the calibration of a dark-matter detector

A new method has been proposed for obtaining a beam of monoenergetic neutrons with almost arbitrary energies. The production of the beam for the calibration of a dark-matter detector with liquid argon as a working medium has been described.

Dark currents of a tandem accelerator with vacuum insulation

The dark currents flowing in the high-voltage gaps of an electrostatic tandem accelerator with vacuum insulation and the effects associated with their occurrence are investigated. This accelerator, featuring a fast rate of charged particle acceleration and a large surface area of the accelerating electrodes, has been designed to produce a proton beam with an energy of 2 MeV and a constant current of up to 10 mA.

Effect of the residual gas on the lithium layer of a neutron-generating target

An epithermal neutron source based on a tandem accelerator is being constructed at the Budker Institute of Nuclear Physics for use in neutron capture therapy at a cancer clinic. A lithium neutron-generating target obtained by deposition of lithium onto the target substrate is one of the key elements of the facility. The effect of residual gas on the lithium layer composition has been investigated using a secondary-ion mass spectrometer.

Obtaining a proton beam with 5-mA current in a tandem accelerator with vacuum insulation

Suppression of parasitic electron flows and positive ions formed in the beam tract of a tandem accelerator with vacuum insulation allowed a more than threefold increase (from 1.6 to 5 mA) in the current of accelerated 2-MeV protons. Details of the modification are described. Results of experimental investigation of the suppression of secondary charged particles and data on the characteristics of accelerated proton beam with increased current are presented.

Measuring the neutron spectrum of the accelerator-based source using the time-of-flight method

The time-of-flight technique with a new method for generating short radiation bursts has been used to measure the neutron spectrum of the accelerator-based source with a stationary proton beam. Specific problems arising thereby and methods for solving them are described. The measured spectrum of neutrons in the reaction 7Li(p, n)7Be at a proton energy of 1.915 MeV is presented and compared to the calculation. This spectrum is shown to comply with the requirements for the neutron beam used in neutron capture therapy.

Radiation accompanying the absorption of 2-MeV protons in various materials

For the development of boron neutron-capture therapy of malignant tumors, a source of epithermal neutrons on the basis of a tandem accelerator with a vacuum insulation and a lithium target was created and launched. With the aim of optimizing the neutron-producing target, various structure materials were irradiated with a proton beam. The results obtained bymeasuring the dose rate and radiation spectrum upon the absorption of 2-MeV protons are presented, and the choice of tantalum for an optimum material of the target substrate was explained.