The influence of nitrogen admixture on concentration of an electronic–excited helium atoms in atmospheric pressure glow discharge
The concentrations of the low-excited helium atoms in states 2¹S, 2¹P, 2³S and 2³P were determined in the atmospheric pressure glow discharge in helium (99.98%He) and in helium with a nitrogen admixture (99.5%He + 0.5%N2). It was shown that the adding of nitrogen into helium leads to the drastically...
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
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irk-123456789-798072015-04-05T03:02:35Z The influence of nitrogen admixture on concentration of an electronic–excited helium atoms in atmospheric pressure glow discharge Arkhipenko, V.I. Kirillov, A.A. Simonchik, L.V. Zgirouski, S.M. Low temperature plasma and plasma technologies The concentrations of the low-excited helium atoms in states 2¹S, 2¹P, 2³S and 2³P were determined in the atmospheric pressure glow discharge in helium (99.98%He) and in helium with a nitrogen admixture (99.5%He + 0.5%N2). It was shown that the adding of nitrogen into helium leads to the drastically reduction of concentration of both the low-excited helium atoms and ions. Визначено концентрації низьких збуджених атомів гелію в станах 2¹S, 2¹P, 2³S і 2³P у тліючому розряді при атмосферному тиску в гелії (99.98%He) і в суміші гелію з азотом (99.5%He + 0.5%N2). Показано, що додавання азоту в гелій приводить до істотного зменшення як заселенностей нижніх збуджених рівнів гелію, так і концентрації іонів гелію. Определены концентрации низких возбужденных атомов гелия в состояниях 2¹S, 2¹P, 2³S и 2³P в тлеющем разряде при атмосферном давлении в гелии (99.98%He) и в смеси гелия с азотом (99.5%He + 0.5%N2). Показано, что добавление азота в гелий приводит к существенному уменьшению как заселенностей нижних возбужденных уровней гелия, так и концентрации ионов гелия. 2005 Article The influence of nitrogen admixture on concentration of an electronic–excited helium atoms in atmospheric pressure glow discharge / V.I. Arkhipenko, A.A. Kirillov, L.V. Simonchik, S.M. Zgirouski // Вопросы атомной науки и техники. — 2005. — № 2. — С. 199-201. — Бібліогр.: 9 назв. — англ. 1562-6016 PACS: 52.80.Hc http://dspace.nbuv.gov.ua/handle/123456789/79807 en Вопросы атомной науки и техники Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
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Low temperature plasma and plasma technologies Low temperature plasma and plasma technologies |
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Low temperature plasma and plasma technologies Low temperature plasma and plasma technologies Arkhipenko, V.I. Kirillov, A.A. Simonchik, L.V. Zgirouski, S.M. The influence of nitrogen admixture on concentration of an electronic–excited helium atoms in atmospheric pressure glow discharge Вопросы атомной науки и техники |
| description |
The concentrations of the low-excited helium atoms in states 2¹S, 2¹P, 2³S and 2³P were determined in the atmospheric pressure glow discharge in helium (99.98%He) and in helium with a nitrogen admixture (99.5%He + 0.5%N2). It was shown that the adding of nitrogen into helium leads to the drastically reduction of concentration of both the low-excited helium atoms and ions. |
| format |
Article |
| author |
Arkhipenko, V.I. Kirillov, A.A. Simonchik, L.V. Zgirouski, S.M. |
| author_facet |
Arkhipenko, V.I. Kirillov, A.A. Simonchik, L.V. Zgirouski, S.M. |
| author_sort |
Arkhipenko, V.I. |
| title |
The influence of nitrogen admixture on concentration of an electronic–excited helium atoms in atmospheric pressure glow discharge |
| title_short |
The influence of nitrogen admixture on concentration of an electronic–excited helium atoms in atmospheric pressure glow discharge |
| title_full |
The influence of nitrogen admixture on concentration of an electronic–excited helium atoms in atmospheric pressure glow discharge |
| title_fullStr |
The influence of nitrogen admixture on concentration of an electronic–excited helium atoms in atmospheric pressure glow discharge |
| title_full_unstemmed |
The influence of nitrogen admixture on concentration of an electronic–excited helium atoms in atmospheric pressure glow discharge |
| title_sort |
influence of nitrogen admixture on concentration of an electronic–excited helium atoms in atmospheric pressure glow discharge |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2005 |
| topic_facet |
Low temperature plasma and plasma technologies |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/79807 |
| citation_txt |
The influence of nitrogen admixture on concentration of an electronic–excited helium atoms in atmospheric pressure glow discharge / V.I. Arkhipenko, A.A. Kirillov, L.V. Simonchik, S.M. Zgirouski // Вопросы атомной науки и техники. — 2005. — № 2. — С. 199-201. — Бібліогр.: 9 назв. — англ. |
| series |
Вопросы атомной науки и техники |
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2025-07-06T03:46:51Z |
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2025-07-06T03:46:51Z |
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1836867767317299200 |
| fulltext |
THE INFLUENCE OF NITROGEN ADMIXTURE ON CONCENTRATION
OF AN ELECTRONIC–EXCITED HELIUM ATOMS IN ATMOSPHERIC
PRESSURE GLOW DISCHARGE
V.I. Arkhipenko, A.A. Kirillov, L.V. Simonchik, S.M. Zgirouski
Institute of Molecular and Atomic Physics NASB, Minsk, Belarus, simon@imaph.bas-net.by
The concentrations of the low-excited helium atoms in states 21S, 21P, 23S and 23P were determined in the
atmospheric pressure glow discharge in helium (99.98%He) and in helium with a nitrogen admixture (99.5%He +
0.5%N2). It was shown that the adding of nitrogen into helium leads to the drastically reduction of concentration of
both the low-excited helium atoms and ions.
PACS: 52.80.Hc
1. INTRODUCTION
There is large increasing interest in atmospheric
pressure glow discharges (APGD) because they can be
used for a wide range of technological applications
without the need of vacuum systems. Nonthermal
atmospheric plasmas of the APGDs are typically
generated using voltage excitation at dc, at the 50 or 60Hz
mains frequency, or at higher frequencies - from kilohertz
to megahertz - between two electrodes of different
configuration (plane—plane, pin—plane, microhollow
cathode,..). Some of fundamental properties of APGD
plasmas have been characterized experimentally including
discharge dynamics, optical emission, and densities of the
charged and excited particles.
As a rule, helium in mixture with other gases is
used as working gas in discharges at atmospheric pressure
[1, 2]. However, at present there isn’t a complete
understanding of the gas discharge physics in gas
mixtures at atmospheric pressure. As it was shown in [2],
for example, a small addition of other gases (~1%) into
working gas of barrier discharge plays a significant role in
stability of this discharge. On the base of numerical
calculation it is approved in [3] that even the residual gas
admixtures with concentration ~0.5∙10-4 % exert a
significant influence on both the plasma composition and
the gas discharge parameters in atmospheric pressure
discharge.
The self-sustained normal dc APGD in helium [4]
is a convenient object for investigations of the kinetics of
the weakly ionized nonequilibrium plasma at atmospheric
pressure having a complicated composition. In present
paper the concentrations of the low-excited helium atoms
in states 21S, 21P, 23S and 23P were determined in the
APGD in helium (99.98%He) and in helium with a
nitrogen admixture (99.5%He + 0.5%N2). The low-
excited levels of helium are participated at many plasma
chemical reactions. Therefore their concentrations are one
of major parameters of nonequilibrium plasma of the
APGD.
2. EXPERIMENTAL SETUP
The self-sustained normal dc APGD was created in
the pressurized chamber between two electrodes: the
weakly rounded tungsten anode (diameter 6 mm) and flat
circular steel cathode (diameter 30 mm). Interelectrode
gap was about 4 mm. The impurity concentrations in
helium flow (H2, N2, O2, Ar, CO2, CO, Ne, H2O) were not
exceeding 0.02 %. The mixture of helium with admixture
of nitrogen (in ratio 99.5%He: 0.5%N2) was prepared in
gas-cylinder in advance. Experiments were fulfilled at
discharge current of 1 Ampere. An interelectrode voltage
was ~ 200 V and ~240 V in APGD in helium and in
mixture, correspondingly. The intensive water cooling of
cathode was ensured due to its special design.
Schematic diagram of experimental apparatus for an
absorption line profile registration is shown in fig. 1. The
discharge image was focused on entrance slit of a double
grating monochromator (MDD 500x2) of high resolution.
Problems of Atomic Science and Technology. Series: Plasma Physics (11). 2005. № 2. P. 199-201 199
Fig.1. Schematic diagram of the experimental
apparatus:
1 – probing emission source, 2, 6, 11 – lens, 3 –
chopper, 4, 10 – slit-diaphragms, 5 -- synchronous
sensor, 7 discharge chamber, 8 – discharge power
supply, 9 – windows, 12 – monochromator, 13 –
photomultiplier, 14 – selective amplifier, 15 –
synchronous detector, 16 – high-voltage power supply,
17 – control block, 18 – A/D converter, 19 – computer,
20 – flowmeter, 21 – gas-cylinder.
Fig.1. Schematic diagram of the experimental apparatus:
1 – probing emission source, 2, 6, 11 – lens, 3 –chopper, 4,
10 – slit-diaphragms, 5 -- synchronous sensor,
7– discharge chamber, 8 – discharge power supply,
9– windows, 12 – monochromator, 13 – photomultiplier, 14
– selective amplifier, 15 – synchronous detector,
16 – high-voltage power supply, 17 – control block,
18 – A/D converter, 19 – computer, 20 – flowmeter,
21 – gas-cylinder
A Gaussian instrumental profile was ~ 0.01 nm. To
determine the concentrations of the excited helium atoms
the absorption spectroscopy method was used. The APGD
was highlighted parallel to the cathode surface by a probing
emission. A halogen incandescent lamp KGM-12-50 was
used as probing light source for getting the absorption
lines in visible spectral region. The original light source
on base of arc with thermionic cathode [5] was used in the
UV region. A probing light emission was focused in
plasma volume located on the discharge axes and than
was collected on entrance slit of monochromator together
with a discharge emission. To obtain the needed
resolution in axial direction two slit-diaphragms were
used. The electrical signal proportionate to the probing
emission intensity was separated from a common
photomultiplier signal due to both the modulation of the
probing emission and the using of a selective amplifier.
To make better a signal/noise ratio the synchronous
detection was used as well.
The spectra of the probing light emission before and
after passing through plasma were registered in
experiments. Calculation of the excited helium atom
concentrations in states 21S, 21P, 23S and 23P was fulfilled
by numerical integration of the measured absorption line
profiles at the wavelength 501.6, 667.8, 388.9 and
587.6nm, correspondingly. An axial concentration
distribution was obtained due to a moving of discharge
chamber by step motor in the discharge axes direction.
3. EXPERIMENTAL RESULTS AND
DISCUSSION
The emission spectrum of the APGD plasma consists
of the intensive lines of neutral helium atoms. The more
weak lines of the hydrogen, nitrogen, oxygen and other
elements are observed. The molecular bands are taken
place in spectrum as well. The N 2
B2 Σ u
−X 2 Σ g
electron-vibration bands (1,0) 358.2 nm, (0,0) 391.4 nm,
(0,1) 427.8 nm and (0,2) 470 nm of first negative system
of nitrogen have higher intensities. The (A2Σ+-X2Πi)
electron-vibration bands (0,0) 308.nm, (1,1) 314,3 nm of
hydroxyl are intensive in UV region. More intensive
spectra are registered in negative glow.
200
a b
501,4 501,6 501,8
0,0
0,2
0,4
0,6
0,8
1,0
T
ra
ns
m
is
si
on
, n
or
m
.
Wavelengh, nm
He(21S - 31P)
667,6 667,8 668,0
0,0
0,2
0,4
0,6
0,8
1,0
T
ra
ns
m
is
si
on
, n
or
m
.
Wavelength, nm
He(21P - 31D)
c d
388,8 389,0
0,0
0,2
0,4
0,6
0,8
1,0
T
ra
ns
m
itt
an
ce
, n
or
m
.
Wavelength, nm
He(23S - 33P)
587,4 587,6
0,0
0,2
0,4
0,6
0,8
1,0
T
ra
ns
m
itt
an
ce
. n
or
m
.
Wavelength, nm
He(23P - 33D)
Fig. 2. The transmission line profiles at the wavelength
501.6 nm (a), 667.8 nm (b), 388.9 nm (c) и 587.6 nm (d),
solid curve – discharge in helium, dashed one in mixture
a
0 50 100 150 200 250
1E12
1E13
1E14
He(21S)
He(21P)
He(23S)
He(23P)
C
on
ce
nt
ra
tio
n,
c
m
-3
Distance, µm
He 99.98%
b
0 50 100 150 200
1E11
1E12
1E13
C
on
ce
nt
ra
tio
n,
c
m-
3
Distance, µm
He+0.5%N2
Fig. 3. Axial distributions of the exited helium atom concentrations in helium dischsrge (a) and in helium mixture
discharge (b)
The adding of nitrogen into working gas helium leads
to an increase of intensities of the electron systems of
molecular nitrogen. An interesting fact is that the intensity
of the second positive system of nitrogen increases more
quickly in comparison with one of the first negative
system of nitrogen while concentration of nitrogen in
mixture is increased. At the same time the bands of the
second positive system of nitrogen are not observed in
helium discharge. Therefore, a significant population of
both the N2
+(B2Σ+) and the N2(С3Пu) levels takes place in
the APGD in helium-nitrogen mixture.
The adding of nitrogen in helium influences on
populations of the low-excited helium atom levels (n = 2)
as well. The transmission line profiles at the wavelength
501.6, 667.8, 388.9 and 587.6 nm are presented in fig. 3.
These profiles were registered in negative glow. It is seen
at the adding of the 0.5% nitrogen in helium a significant
decrease of an absorption is observed at all lines.
Using the experimental transmission profile (Fig. 2)
the concentration of atoms Nn in corresponding state can
be calculated as follow [5]
Nn ≈ с/(0.026 fnm lλ0
2) ∫ ln(I0/Iλ)dλ, , (1)
where λ0 – wavelength of corresponding line, l –
thickness of absorption layer which was supposed to be
homogeneous, c – light velocity, fmn – oscillator force.
The transmission profiles were registered at different
distances from cathode. Using these experimental profiles
and formula (1) the corresponding axial distributions of
concentration of low-excited helium atoms were obtained.
They are presented in fig. 3. It can be seen that the
concentration of the excited helium atoms in helium-
nitrogen mixture (99.5%He + 0.5%N2) is less one order of
magnitude than in case of pure helium. The axial
concentration distributions are analogous for discharges
in helium and helium-nitrogen mixture. Maximal
concentration magnitude takes place in cathode region at
distance about 0.1 mm from cathode surface.
Let we make the analysis of the main reactions in the
both APGDs. The low-exited levels of helium atoms play
an important role in stepped ionization processes. The
role of this ionization mechanism in the APGD is more
significant in comparison with one in the lower pressure
glow discharge. In the electric fields E/N0 ≤ 10-15V∙cm2
and at the ionization degree more 10-5 a stepped ionization
in the APGD plasma is more important than a direct
ionization by electron collision even at free exit of light
emission [6]. Naturally, a light reabsorption increases the
stepped ionization efficiency. The charged particles are
produced in follow reactions with participation of excited
helium atoms He* [7]:
He* + He* → He+ + He +e , (2)
He*(n=3) + He → He2
+ + e . (3)
The scheme of reactions in gas mixture discharge
should be added by the follow reactions describing an
interaction of helium atoms and molecules with the
nitrogen molecules [7-9]
He ¿ N2 He N 2
e ,
(4)
He23 Σ u
N 2He HeN 2
e ,
(5)
2He N He N N 0,3 eV+ ++ → + + + , (6)
201
a
0 50 100 150 200 250
1E12
1E13
1E14
He(21S)
He(21P)
He(23S)
He(23P)
C
on
ce
nt
ra
tio
n,
c
m
-3
Distance, µm
He 99.98%
b
0 50 100 150 200
1E11
1E12
1E13
C
on
ce
nt
ra
tio
n,
c
m-
3
Distance, µm
He+0.5%N2
Fig. 3. Axial distributions of the exited helium atom concentrations in helium dischsrge (a) and in helium mixture
discharge (b)
a b
501,4 501,6 501,8
0,0
0,2
0,4
0,6
0,8
1,0
T
ra
ns
m
is
si
on
, n
or
m
.
Wavelengh, nm
He(21S - 31P)
667,6 667,8 668,0
0,0
0,2
0,4
0,6
0,8
1,0
T
ra
ns
m
is
si
on
, n
or
m
.
Wavelength, nm
He(21P - 31D)
c d
388,8 389,0
0,0
0,2
0,4
0,6
0,8
1,0
T
ra
ns
m
itt
an
ce
, n
or
m
.
Wavelength, nm
He(23S - 33P)
587,4 587,6
0,0
0,2
0,4
0,6
0,8
1,0
T
ra
ns
m
itt
an
ce
. n
or
m
.
Wavelength, nm
He(23P - 33D)
Fig. 2. The transmission line profiles at the wavelength
501.6 nm (a), 667.8 nm (b), 388.9 nm (c) и 587.6 nm (d),
solid curve – discharge in helium, dashed one in mixture
He
2
N 2He HeN 2
.
(7)
Reaction (4) is in charge of a decrease of the excited
helium atom concentrations at a nitrogen adding, because
a decrease of the He* atom concentration due to the
temperature growth is neglible. Since a significant part (a
few tens of percents) of created molecular ions of
nitrogen is in the excited B2Σ+ state, the quenching of
excited helium atoms is accompanied by emission in first
negative system of nitrogen. The creation of molecular
nitrogen ion result in a quenching process of the He2(23Σ
u
+) molecule at collision of metastable helium atom with
nitrogen molecule (reaction 5). Reactions (6), (7) describe
the processes of recharge at collision of both the atomic
and molecular helium with nitrogen molecules.
Thus, the adding of nitrogen into helium leads to the
reduction of concentration of both the low-excited
helium atoms and ions. As result of that, the nitrogen
becomes in charge of the maintenance of the APGD in
helium-nitrogen mixture even in presence of small
nitrogen admixture.
The work was supported by BRFBR (grant T04-181).
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pressure controlled by dielectric barrier// J. Appl.
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3. X. Yuan, L.L. Raja. Role of trace impurities in large-
volume noble gas atmospheric-pressure glow
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p.814-816.
4. V. I. Arkhipenko, S. M. Zgirovski, L.V. Simonchik.
Determination of the Metastable Helium Atoms
Concentration in an Atmospheric-Pressure Glow
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p.530-533.
5. V. I. Arkhipenko, S. M. Zgirovski, et. al. Light
Source with Termionic Cathode// J. Appl. Spectr.
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6. A.A. Belevtsev, L.M. Biberman. Step ionization
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Energetika i transport. 1978, N4, p.106-113 (in
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7. B.M. Smirnov. Excited atoms. Moscow:
“Energoizdat”, 1982 (in Russian).
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p.2798-2802.
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1.
ВЛИЯНИЕ ДОБАВОК АЗОТА НА КОНЦЕНТРАЦИЮ ЭЛЕКТРОННО-ВОЗБУЖДЕННЫХ АТОМОВ
ГЕЛИЯ В ТЛЕЮЩЕМ РАЗРЯДЕ АТМОСФЕРНОГО ДАВЛЕНИЯ
В.И. Архипенко, А.А. Кириллов, Л.В. Симончик, С.М. Згировский
Определены концентрации низких возбужденных атомов гелия в состояниях 21S, 21P, 23S и 23P в тлеющем
разряде при атмосферном давлении в гелии (99.98%He) и в смеси гелия с азотом (99.5%He + 0.5%N2). Показано,
что добавление азота в гелий приводит к существенному уменьшению как заселенностей нижних
возбужденных уровней гелия, так и концентрации ионов гелия.
ВПЛИВ ДОБАВОК АЗОТУ НА КОНЦЕНТРАЦІЮ ЭЛЕКТРОННО-ЗБУЖДЕНИХ АТОМІВ ГЕЛІЮ В
ТЛІЮЧОМУ РОЗРЯДІ АТМОСФЕРНОГО ТИСКУ
В.І. Архипенко, А.А. Кирилов, Л.В. Симончик, С.М. Згировський
Визначено концентрації низьких збуджених атомів гелію в станах 21S, 21P, 23S і 23P у тліючому розряді при
атмосферному тиску в гелії (99.98%He) і в суміші гелію з азотом (99.5%He + 0.5%N2). Показано, що додавання
азоту в гелій приводить до істотного зменшення як заселенностей нижніх збуджених рівнів гелію, так і
концентрації іонів гелію.
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