EXPERIMENTAL RESULTS OF THE BEAM DYNAMICS BY USING GLASS CAPILLARIES FOR THE ESA-2

A.E. Lagutinª, A.N. Sevchenko

A.N. Sevchenko Scientific Research Institute of Applied Physical Problems, Belarussian State University, Minsk, Belorussia

Abstract

In comparison with the existing tools for formation of micrometer-sized beams, capillary method is undoubtedly simpler and less expensive. At the same time, is satisfies all the requirements of submicron Rutherford backscattering spectrometry or analysis with application of induced characteristic X-rays. The processes of interaction of accelerated protons with the surface of insulating capillaries have been investigated to determine the character of motion of particles during such interaction. The angular distributions of 240 keV protons transmitted through glass capillaries have been measured, and splitting of the distribution into a series of lines equally spaced from each other is revealed. Protons passed through the glasses (boron-silicon) capillaries with a diameter of 0.1, 0.5 and length of 30, 65, 178 mm at the axial entry angles of particles ± 0.2º and in the range of proton beam currents from 8.5∙10^-13 to 10^-11 A. Ion-optical characteristics of an tapered glass capillary were studied. We present evidence of the focusing effects of fine glass capillary optics for proton ion beams. The glass capillary optics is formed by a puller as to have inlet diameters of about 3 mm and outlet diameters of submicrons. The total length of the optics is about 80 mm. Impingent 240 keV protons to such optics are reflected by the inner wall several times, in a very similar process to the so-called surface channeling.

ª – corresponding author

Paper 

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