Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cubic boron nitride: a new prospective material for ultracold neutron
  application   For the first time, the neutron optical wall-potential of natural cubic boron
nitride (cBN) was measured at the ultracold neutron (UCN) source of the
research reactor TRIGA Mainz using the time-of-flight method (TOF). The samples
investigated had a wall-potential of (305 +/- 15) neV. This value is in good
agreement with the result extracted from neutron reflectometry data and
theoretical expectations. Because of its high critical velocity for UCN and its
good dielectric characteristics, cubic boron nitride coatings (isotopically
enriched) will be useful for a number of applications in UCN experiments.

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The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph
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The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
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The categories of this paper are: nlin
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The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph