Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Performance of Large Area X-ray Proportional Counters in a Balloon
  Experiment   ASTROSAT is India's first satellite fully devoted to astronomical
observations covering a wide spectral band from optical to hard X-rays by a
complement of 4 co-aligned instruments and a Scanning Sky X-ray Monitor. One of
the instruments is Large Area X-ray Proportional Counter with 3 identical
detectors. In order to assess the performance of this instrument, a balloon
experiment with two prototype Large Area X-ray Proportional Counters (LAXPC)
was carried out on 2008 April 14. The design of these LAXPCs was similar to
those on the ASTROSAT except that their field of view (FOV) was 3$^{\circ}$
$\times$ 3$^{\circ}$ versus FOV of 1$^{\circ}$ $\times$ 1$^{\circ}$ for the
LAXPCs on the ASTROSAT. The LAXPCs are aimed at the timing and spectral studies
of X-ray sources in 3-80 keV region. In the balloon experiment, the LAXPC,
associated electronics and support systems were mounted on an oriented platform
which could be pre-programmed to track any source in the sky. A brief
description of the LAXPC design, laboratory tests, calibration and the detector
characteristics is presented here. The details of the experiment and background
counting rates of the 2 LAXPCs at the float altitude of about 41 km are
presented in different energy bands. The bright black hole X-ray binary Cygnus
X-1 (Cyg X-1) was observed in the experiment for $\sim$ 3 hours. Details of Cyg
X-1 observations, count rates measured from it in different energy intervals
and the intensity variations of Cyg X-1 detected during the observations are
presented and briefly discussed.

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The categories of this paper are: q-alg
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The categories of this paper are: dg-ga
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The categories of this paper are: math-ph
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The categories of this paper are: funct-an
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The categories of this paper are: eess
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The categories of this paper are: atom-ph
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The categories of this paper are: solv-int
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-th
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The categories of this paper are: adap-org
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The categories of this paper are: quant-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-th
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The categories of this paper are: cmp-lg