Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A "hybrid"-type system for an achromatic focusing of ions   It is known, that at high energies of ions (more than 10 MeV for light ions)
the focusing by magnetic quadrupole fields is most effective, whereas at small
energies (less than 1 MeV) - the focusing by electrical quadrupole fields. At
intermediate energies of ions (from 1 to 10 MeV) the efficiency of each of
these types of a focusing is reduced. The authors offer to utilize for this
purpose the "hybrid" type of focusing systems consisting of sequence of
electrical and magnetic quadrupole lenses, which are localized in the same
space. For making fields of electrical quadrupole lenses it is offered to
utilize RF quadrupoles. The RF electrical quadrupoles are created due to the
relevant configuration of drift tubes in the vicinity of an accelerating gap.
As a result of the general theoretical analysis and calculation of concrete
versions of practical realizations it is shown that the given system has
advantage as contrasted to by known analogs in the field of medium energies.
The velocity band of ions, in which the stable motion is ensured, is
essentially changed, and the focusing becomes "achromatic". The calculations
have been performed for protons with velocities 0.5-1.0 % of light velocity, at
the gradients of electrical field up to 50 kV per square cm, and the gradients
of magnetic field up to 1 T/m. Achromaticity of this system allows to lower a
radiative activation of accelerator and to reduce damage of electrode surfaces
by lost ions.

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The categories of this paper are: astro-ph
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
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The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
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The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
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The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
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The categories of this paper are: nlin
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The categories of this paper are: quant-ph