Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Absolute Calibration of the DANCE Thermal Neutron Beam using Sodium
  Activation   The measurement of the neutron capture cross-section as a function of energy
in the thermal range requires a precise knowledge of the absolute neutron flux.
In this paper a new method of calibrating a thermal neutron beam using the
controlled activation of sodium is described. The method is applied to the
FP-14 Time Of Flight neutron beam line at the Los Alamos Neutron Science Center
to calibrate the beam to a precision of $\pm5$%.

36
The categories of this paper are: cmp-lg
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The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
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The categories of this paper are: bayes-an
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The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
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The categories of this paper are: adap-org
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The categories of this paper are: eess
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The categories of this paper are: patt-sol
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The categories of this paper are: mtrl-th
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The categories of this paper are: plasm-ph
1
The categories of this paper are: cs