Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Effect of Inhomogeneous Surface Disorder on the Superheating Field
  of Superconducting RF Cavities   Recent advances in surface treatments of Niobium superconducting radio
frequency (SRF) cavities have led to substantially increased Q-factors and
maximum surface field. This poses theoretical challenges to identify the
mechanisms responsible for such performance enhancements. We report theoretical
results for the effects of inhomogeneous surface disorder on the superheating
field --- the surface magnetic field above which the Meissner state is globally
unstable. We find that inhomogeneous disorder, such as that introduced by
infusion of Nitrogen into the surface layers of Niobium SRF cavities, can
increase the superheating field above the maximum for superconductors in the
clean limit or with homogeneously distributed disorder. Homogeneous disorder
increases the penetration of screening current, but also suppresses the maximum
supercurrent. Inhomogeneous disorder in the form of an impurity diffusion layer
biases this trade-off by increasing the penetration of the screening currents
into cleaner regions with larger critical currents, thus limiting the
suppression of the screening current to a thin dirty region close to the
surface. Our results suggest that the impurity diffusion layers play a role in
enhancing the maximum accelerating gradient of Nitrogen treated Niobium SRF
cavities.

10
The categories of this paper are: q-bio
2
The categories of this paper are: math
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
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
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The categories of this paper are: quant-ph
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The categories of this paper are: astro-ph
36
The categories of this paper are: cmp-lg
18
The categories of this paper are: econ