Ivan Shchudlo

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.

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.

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.

Measurement of the Proton Beam Profile via an Activation Method of Diagnostics

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. Neutrons on the facility are generated during the threshold reaction 7Li(p, n)7Be which occurs when the proton beam is thrown on the lithium target. To control the neutron output it is necessary to monitor the parameters of the accelerated proton beam. The spatial distribution of the accelerated proton beam was measured exactly on the lithium target, using an activation method of diagnostics.

Obtainment of 5 mA 2 MeV Proton Beam in the Vacuum Insulation Tandem Accelerator

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 methods of suppression of undesirable charged particles and the results of experiments.

Experiments to increase the parameters of the vacuum insulation tandem accelerator for boron neutron capture therapy

An epithermal neutron source that is based on a vacuum insulation tandem accelerator (VITA) and lithium target was created in the Budker Institute of Nuclear Physics for the development of boron neutron capture therapy (BNCT). A stationary proton beam with 2 MeV energy and 1.6 mA current has been obtained. To carry out BNCT, it is necessary to increase the beam parameters up to 2.3 MeV and 3 mА. Ways to increase the parameters of the proton beam have been proposed and discussed in this paper. The results of the experiments are presented.