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November 13-14, 2017 Paris, France
5
th
International Conference on
PLASMA CHEMISTRY AND
PLASMA PROCESSING
Journal of Biotechnology and Phytochemistry
Volume 1, Issue 2
Plasma Chemistry 2017
Mid-infrared emission spectroscopy of laser
generated carbon plasmas
Laszlo Nemes
Science adviser, Hungary
M
id infrared time-resolved emission (IrLIBS) spectra were
recorded from laser-induced carbon plasma at Hampton
University, Virginia, USA. These spectra constitute the first
report of carbon materials LIB spectroscopy in the mid infrared
range. The plasma was induced using a Q-switched Nd: YAG
laser. The laser beam was focused to high purity graphite pellets
mounted on a translation stage. Mid infrared emission from the
plasma in atmospheric pressure background gases was detected
by a cooled MCT detector in the range 4.5-11.6 micrometer,
using long-pass filters. The spectra were taken in argon, helium
and also in nitrogen and were background corrected and
noise filtered. A 0.15 m spectrometer with gratings blazed at 8
micrometer was used. Spectral resolution was around 80 nm.
Several spectral runs were averaged using a boxcar averager.
Even though a gate delay of 10 to 20 microseconds was used
there were strong backgrounds in the spectra. Superimposed on
this background broad and noisy emission bands were observed,
the form and position of which depended somewhat on the
ambient gas. In argon, for instance strong bands were observed
around 4.8, 6.0 and 7.5 micrometer. Using atomic spectral data
by NIST it could be concluded that carbon and argon lines from
neutral and ionized atoms are very weak in this spectral region.
The width of the infrared bands also supports molecular origin.
The infrared emission bands were thus compared to vibrational
features of carbon molecules (excluding C
2
) and clusters of
various sizes on the basis of previous carbon cluster infrared
absorption and emission spectroscopic analyses in the literature
and quantum chemical calculations. Applications of these results
are expected in materials science, environmental chemistry and
also in astrophysics.
Biography
Laszlo Nemes is graduated and certified chemical engineer in 1959 from the
Technical University of Budapest. He joined at the research network of the
Hungarian Academy of Sciences and he have been associated ever since with
that organization. His main fields are molecular spectroscopy, laser and plasma
spectroscopy. He got his Ph D degree from the Technical University of Budapest
(1965), a DSc.degree from the Hungarian Academy of Sciences (1982), and
posses "venia legendi" as a habilitated, titular professor in physical chemistry at the
Technical University of Budapest (1995). He held several grants and stipends to do
research and teaching abroad. He also visited Great Britain in the years 1964-65. In
1972-73 he had a Dozentenstipendium from the German Alexander von Humboldt-
Stiftung for work at the University of Kiel , later he was reactivated in 1982 as
humboldt-fellow at the Justus-Liebig-University, Giessen. In 1985 he was visiting
scientist at the Herzberg institute of astrophysics, National Research Council of
Canada, Ottawa and in 1986 a state professorship in France at Villeneuve d'Ascq
(Universite de Lille). In 1990 he spent time at the Catholic University of Nijmegen,
Laboratory of Molecular and Laser Physics (The Netherlands). In 1991 he was
visiting research scientist at the chemistry department, University of Michigan, Ann
Arbor, USA. He worked at the University of Waterloo, Canada in the Center for
Molecular Beams and Laser Chemistry in 1992 and 1993 and he have spent a year
as guest research professor of the Academia Sinica, Taipei, Taiwan at the Institute of
Atomic and Molecular Sciences. Then In 1996 he was W F James professor of pure
and applied science at the St. Francis Xavier University in Nova Scotia, Canada.
Since 1980 he have been active in the field of laser induced chemistry and the
emission spectroscopic studies of laser generated plasmas. In 2006 he retired but
remained active at my former institute, the Central Research Institute of Chemistry
as science advisor emeritus. Since 3 years he associated with the Research Center
of Natural Sciences of the Hungarian Academy of Sciences, Budapest, as emeritus
science advisor. His CV has been published by several international biographical
organs, first in 1981 in the Who's Who in the World, , USA, then in several other
published works, e.g. in the UK. A compilation of about 80 of his scientific papers
are available at research gate.
nemesl@comunique.huLaszlo Nemes, J Biot Phyt 2017