Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Revision of the Coulomb logarithm in the ideal plasma   The standard picture of the Coulomb logarithm in the ideal plasma is
controversial, the arguments for the lower cut off need revision. The two cases
of far subthermal and of far superthermal electron drift motions are accessible
to a rigorous analytical treatment. We show that the lower cut off $b_{\min}$
is a function of symmetry and shape of the shielding cloud, it is not
universal. In the subthermal case shielding is spherical and $b_{\min}$ is to
be identified with the de Broglie wavelength; at superthermal drift the
shielding cloud exhibits cylindrical (axial) symmetry and $b_{\min}$ is the
classical parameter of perpendicular deflection. In both situations the cut
offs are determined by the electron-ion encounters at large collision
parameters. This is in net contrast to the governing standard meaning that
attributes $b_{\min}$ to the Coulomb singularity at vanishing collision
parameters $b$ and, consequently, assigns it universal validity. The origin of
the contradictions in the traditional picture is analyzed.

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The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
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The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
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The categories of this paper are: chem-ph
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The categories of this paper are: eess
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
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The categories of this paper are: nucl-th
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The categories of this paper are: nucl-ex