Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Studies of a hollow cathode discharge using mass spectrometry and
  electrostatic probe techniques   Hollow cathode discharges (HCD) are capable of generating dense plasmas and
have been used for development of high-rate, low-pressure, high-efficiency
processing machines. The geometric feature of a HCD promotes oscillations of
hot electrons inside the cathode, thereby enhancing ionization, ion bombardment
of inner walls and other subsequent processes. At the same power the hollow
cathode exhibits plasma density one to two orders of magnitude higher than that
of conventional planar electrodes. The aim of the present studies was to obtain
experimental observations about the main features of a dc hollow cathode
discharge in order to evaluate its capability of generating compounds in the
plasma medium, by reaction between sputtered species from the cathode and
radicals from the gas discharge. Especial interest is focused on aluminum
nitride (AlN) formation which is very desirable if a deposition of thin film of
this material is concerned. Plasma properties were inferred from the
current-voltage characteristics of a single Langmuir probe positioned at the
inter-cathode space. Through mass spectrometry technique some species in the
plasma gas phase could be monitored for various operating conditions of the
discharge. This mass analysis together with the probe measurements gives
guidance for optimization of AlN generation in the discharge consequently for
deposition of thin films of this material.

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The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph
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The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys