Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Laser ablation production of Ba, Ca, Dy, Er, La, Lu, and Yb ions   We use a pulsed nitrogen laser to produce atomic ions by laser ablation,
measuring the relative ion yield for several elements, including some that have
only recently been proposed for use in cold trapped ion experiments. For
barium, we monitor the ion yield as a function of the number of applied
ablation pulses for different substrates. We also investigate the ion
production as a function of the pulse energy, and the efficiency of loading an
ion trap as a function of radiofrequency voltage.

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The categories of this paper are: astro-ph
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The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
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The categories of this paper are: hep-ex
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The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
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The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
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The categories of this paper are: acc-phys
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The categories of this paper are: eess
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The categories of this paper are: math-ph
9
The categories of this paper are: nlin