Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Experimental evidence for electric surface resistance in niobium   Identifying the loss mechanisms of niobium cavities enables an accurate
determination of applications for future accelerator projects and points to
research topics required to mitigate current limitations. For several cavities
an increasing surface resistance above a threshold field, saturating at higher
field has been observed. Measurements on samples give evidence that this effect
is caused by the surface electric field. The measured temperature and frequency
dependence is consistent with a model that accounts for these losses by
interface tunnel exchange between localized states in oxides formed along grain
boundaries and the adjacent superconductor.

26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
0
The categories of this paper are: hep-ph
24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph