Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Statistics of the Charge Spectrum of Photo-Multipliers and Methods for
  Absolute Calibration   We derive the full expression for the shape of the charge spectrum that
results from the illumination of a photo-multiplier tube. The derivation is for
low intensity illumination with constant gain, a common condition for most
nuclear and particle physics applications. Under these conditions, it is shown
that an analytic expression can be formulated that describes details of the
spectrum including the pedestal and dark noise with excellent fidelity to allow
statistical fits to data. The derivation and full formula using either Gaussian
or Poisson models for gain, and its limiting forms under various simplifying
assumptions are presented with strategies on their use. The analytic
description can be used to formulate data acquisition strategies to perform
precise absolute calibration of photo-multipliers, the digitizers, and the data
acquisition system.

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The categories of this paper are: math
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The categories of this paper are: q-alg
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The categories of this paper are: astro-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: adap-org
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The categories of this paper are: alg-geom
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The categories of this paper are: q-fin
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The categories of this paper are: plasm-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: gr-qc
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The categories of this paper are: cond-mat
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The categories of this paper are: stat
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The categories of this paper are: nucl-th
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The categories of this paper are: cmp-lg
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The categories of this paper are: supr-con
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The categories of this paper are: hep-lat