Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Current density and reversible magnetization of HgBa(2)Ca(2)Cu(3)O(x)
  superconductors containing randomly oriented columnar defects   Bulk polycrystalline HgBa(2)Ca(2)Cu(3)O(x) materials were irradiated with 0.8
GeV protons to form randomly oriented columnar defects, by induced fission of
Hg-nuclei. Proton fluences from 0 to 35 times 10^{16} cm^{-2} were used to
install defects with area densities up to a "matching field" of 3.4 Tesla.
Studies were conducted on the dependence of the equilibrium magnetization and
the intragrain persistent current density on temperature and applied magnetic
field, at various defect densities. The magnetization was modeled using London
theory with the addition of vortex-defect interactions.

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The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
3
The categories of this paper are: physics
7
The categories of this paper are: hep-th