Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The formation of atomic oxygen and hydrogen in atmospheric pressure
  plasmas containing humidity: picosecond two-photon absorption laser induced
  fluorescence and numerical simulations   Atmospheric pressure plasmas are effective sources for reactive species,
making them applicable for industrial and biomedical applications. We quantify
ground-state densities of key species, atomic oxygen (O) and hydrogen (H),
produced from admixtures of water vapour (up to 0.5%) to the helium feed gas in
a radio-frequency-driven plasma at atmospheric pressure. Absolute density
measurements, using two-photon absorption laser induced fluorescence, require
accurate effective excited state lifetimes. For atmospheric pressure plasmas,
picosecond resolution is needed due to the rapid collisional de-excitation of
excited states. These absolute O and H density measurements, at the nozzle of
the plasma jet, are used to benchmark a plug-flow, 0D chemical kinetics model,
for varying humidity content, to further investigate the main formation
pathways of O and H. It is found that impurities can play a crucial role for
the production of O at small molecular admixtures. Hence, for controllable
reactive species production, purposely admixed molecules to the feed gas is
recommended, as opposed to relying on ambient molecules. The controlled
humidity content was also identified as an effective tailoring mechanism for
the O/H ratio.

7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom