A new method to determine the arbitrary electron energy distribution function (EEDF) from the optical emission spectroscopic measurement in atmospheric-pressure plasma is introduced. The optical emission spectroscopy (OES) continuum emission spectrum, dominated by electron-neutral bremsstrahlung radiation, is analyzed to inspect the usefulness of the conventional OES measurement range for EEDF determination. The EEDF is reconstructed from the OES continuum radiation spectrum by applying machine learning to solve the bremsstrahlung emissivity equation inversely. Through iterative statistical analysis, the presented genetic algorithm can locate the EEDF reliably. Verification of the algorithm shows that theoretical Maxwellian and Druyvesteynian EEDFs can be partially reconstructed from a realistic OES measurement range. Furthermore, preliminary experimental EEDF results of an argon dielectric barrier discharge (DBD) OES measurement are given. The electron energy range and resolution of the determined EEDF are discussed. The results in this paper show potential for accurate determination of the arbitrary EEDF in atmospheric-pressure plasma using simple OES equipment.

1.
A.
Napartovich
, “
Overview of atmospheric pressure discharges producing nonthermal plasma
,”
Plasmas Polym.
6
,
1
14
(
2001
).
2.
X.
Lu
,
S.
Reuter
,
M.
Laroussi
, and
D.
Liu
,
Nonequilibrium Atmospheric Pressure Plasma Jets: Fundamentals, Diagnostics, and Medical Applications
(
CRC Press
,
2019
).
3.
M.
Ito
,
J.-S.
Oh
,
T.
Ohta
,
M.
Shiratani
, and
M.
Hori
, “
Current status and future prospects of agricultural applications using atmospheric-pressure plasma technologies
,”
Plasma Processes Polymers
15
,
1700073
(
2018
).
4.
N.
Puač
,
M.
Gherardi
, and
M.
Shiratani
, “
Plasma agriculture: A rapidly emerging field
,”
Plasma Processes Polym.
15
,
1700174
(
2018
).
5.
S.
Toyokuni
,
Y.
Ikehara
,
F.
Kikkawa
, and
M.
Hori
,
Plasma Medical Science
(
Academic Press
,
2018
).
6.
G.
Fridman
,
G.
Friedman
,
A.
Gutsol
,
A. B.
Shekhter
,
V. N.
Vasilets
, and
A.
Fridman
, “
Applied plasma medicine
,”
Plasma Processes Polym.
5
,
503
533
(
2008
).
7.
M. G.
Kong
,
G.
Kroesen
,
G.
Morfill
,
T.
Nosenko
,
T.
Shimizu
,
J.
Van Dijk
, and
J.
Zimmermann
, “
Plasma medicine: An introductory review
,”
New J. Phys.
11
,
115012
(
2009
).
8.
L.
Di
,
J.
Zhang
, and
X.
Zhang
, “
A review on the recent progress, challenges, and perspectives of atmospheric-pressure cold plasma for preparation of supported metal catalysts
,”
Plasma Processes Polym.
15
,
1700234
(
2018
).
9.
G.
Selwyn
,
H.
Herrmann
,
J.
Park
, and
I.
Henins
, “
Materials processing using an atmospheric pressure, rf-generated plasma source
,”
Contrib. Plasma Phys.
41
,
610
619
(
2001
).
10.
S.
Park
,
W.
Choe
,
H.
Kim
, and
J. Y.
Park
, “
Continuum emission-based electron diagnostics for atmospheric pressure plasmas and characteristics of nanosecond-pulsed argon plasma jets
,”
Plasma Sources Sci. Technol.
24
,
034003
(
2015
).
11.
A. Y.
Nikiforov
,
C.
Leys
,
M.
Gonzalez
, and
J.
Walsh
, “
Electron density measurement in atmospheric pressure plasma jets: Stark broadening of hydrogenated and non-hydrogenated lines
,”
Plasma Sources Sci. Technol.
24
,
034001
(
2015
).
12.
X.
Lu
,
G.
Naidis
,
M.
Laroussi
,
S.
Reuter
,
D.
Graves
, and
K.
Ostrikov
, “
Reactive species in non-equilibrium atmospheric-pressure plasmas: Generation, transport, and biological effects
,”
Phys. Rep.
630
,
1
84
(
2016
).
13.
S.
Park
,
W.
Choe
,
S. Y.
Moon
, and
S. J.
Yoo
, “
Electron characterization in weakly ionized collisional plasmas: From principles to techniques
,”
Adv. Phys.: X
4
,
1526114
(
2019
).
14.
M. J.
Druyvesteyn
, “
Der niedervoltbogen
,”
Z. Phys.
64
,
781
798
(
1930
).
15.
K. G.
Xu
and
S. J.
Doyle
, “
Measurement of atmospheric pressure microplasma jet with langmuir probes
,”
J. Vac. Sci. Technol. A
34
,
051301
(
2016
).
16.
G.
Trenchev
,
S.
Kolev
, and
Z.
Kiss'ovski
, “
Modeling a langmuir probe in atmospheric pressure plasma at different eedfs
,”
Plasma Sources Sci. Technol.
26
,
055013
(
2017
).
17.
R.
Engeln
,
B. L. M.
Klarenaar
, and
O.
Guaitella
, “
Foundations of optical diagnostics in low-temperature plasmas
,”
Plasma Sources Sci. Technol.
29
,
063001
(
2020
).
18.
H.
Akatsuka
, “
Optical emission spectroscopic (oes) analysis for diagnostics of electron density and temperature in non-equilibrium argon plasma based on collisional-radiative model
,”
Adv. Phys.: X
4
,
1592707
(
2019
).
19.
J.
Park
,
I.
Henins
,
H. W.
Herrmann
, and
G. S.
Selwyn
, “
Neutral bremsstrahlung measurement in an atmospheric-pressure radio frequency discharge
,”
Phys. Plasmas
7
,
3141
3144
(
2000
).
20.
S.
Park
,
W.
Choe
,
S.
Youn Moon
, and
J.
Park
, “
Electron density and temperature measurement by continuum radiation emitted from weakly ionized atmospheric pressure plasmas
,”
Appl. Phys. Lett.
104
,
084103
(
2014
).
21.
B.
Klarenaar
,
O.
Guaitella
,
R.
Engeln
, and
A.
Sobota
, “
How dielectric, metallic and liquid targets influence the evolution of electron properties in a pulsed He jet measured by thomson and raman scattering
,”
Plasma Sources Sci. Technol.
27
,
085004
(
2018
).
22.
Q.
Xiong
, “
Advanced optical diagnostics of atmospheric pressure plasma
,” in
Atmospheric Pressure Plasma-from Diagnostics to Applications
(
IntechOpen
,
2019
).
23.
K.
Urabe
,
N.
Shirai
,
K.
Tomita
,
T.
Akiyama
, and
T.
Murakami
, “
Diagnostics of atmospheric-pressure pulsed-dc discharge with metal and liquid anodes by multiple laser-aided methods
,”
Plasma Sources Sci. Technol.
25
,
045004
(
2016
).
24.
K.
Tomita
,
Y.
Inada
,
A.
Komuro
,
X.
Zhang
,
K.
Uchino
, and
R.
Ono
, “
Measurement of electron velocity distribution function in a pulsed positive streamer discharge in atmospheric-pressure air
,”
J. Phys. D: Appl. Phys.
53
,
08LT01
(
2020
).
25.
G.
Hagelaar
and
L.
Pitchford
, “
Solving the Boltzmann equation to obtain electron transport coefficients and rate coefficients for fluid models
,”
Plasma Sources Sci. Technol.
14
,
722
(
2005
).
26.
F.
Taccogna
and
G.
Dilecce
, “
Non-equilibrium in low-temperature plasmas
,”
Eur. Phys. J. D
70
,
1
37
(
2016
).
27.
T. B.
Petrova
,
G.
Petrov
,
D.
Boris
, and
S.
Walton
, “
Non-equilibrium steady-state kinetics of He-air atmospheric pressure plasmas
,”
Phys. Plasmas
24
,
013501
(
2017
).
28.
M.
Capitelli
,
G.
Colonna
,
G.
D'Ammando
,
A.
Laricchiuta
, and
L.
Pietanza
, “
Non-equilibrium vibrational and electron energy distribution functions in mTorr, high-electron-density nitrogen discharges and afterglows
,”
Plasma Sources Sci. Technol.
26
,
034004
(
2017
).
29.
A. Y.
Nikiforov
,
E.-R.
Ionita
,
G.
Dinescu
, and
C.
Leys
, “
Characterization of a planar 8 mm atmospheric pressure wide radiofrequency plasma source by spectroscopy techniques
,”
Plasma Phys. Controlled Fusion
58
,
014013
(
2016
).
30.
K.
Burm
, “
Continuum radiation in a high pressure argon–mercury lamp
,”
Plasma Sources Sci. Technol.
13
,
387
(
2004
).
31.
W.
Bussiere
,
D.
Vacher
,
S.
Menecier
, and
P.
André
, “
Comparative study of an argon plasma and an argon copper plasma produced by an icp torch at atmospheric pressure based on spectroscopic methods
,”
Plasma Sources Sci. Technol.
20
,
045004
(
2011
).
32.
R.
Bazinette
,
J.
Paillol
, and
F.
Massines
, “
Optical emission spectroscopy of glow, townsend-like and radiofrequency dbds in an Ar/NH3 mixture
,”
Plasma Sources Sci. Technol.
24
,
055021
(
2015
).
33.
See http://www.lxcat.net for “
Lxcat: Plasma data exchange project
,” accessed 22 October 2020.
34.
M. M.
Popović
,
S. S.
Popović
, and
S. M.
Vuković
, “
A study of electrical conductivity in heavy noble gases
,”
Fizika
6
,
29
39
(
1974
).
35.
E.
Iordanova
,
J.
Palomares
,
A.
Gamero
,
A.
Sola
, and
J.
van der Mullen
, “
A novel method to determine the electron temperature and density from the absolute intensity of line and continuum emission: Application to atmospheric microwave induced ar plasmas
,”
J. Phys. D: Appl. Phys.
42
,
155208
(
2009
).
36.
A.
Bughgeim
and
A. L.
Bukhgeĭm
,
Volterra Equations and Inverse Problems
(
VSP
,
1999
), Vol.
13
.
37.
A.
Asanov
and
J.
Orozmamatova
, “
About uniqueness of solutions of fredholm linear integral equations of the first kind in the axis
,”
Filomat
33
,
1329
1333
(
2019
).
38.
M.
Mitchell
,
An Introduction to Genetic Algorithms
(
MIT Press
,
1998
).
39.
H.
Akatsuka
,
H.
Onishi
,
T.
van der Gaag
, and
A.
Nezu
, “
Optical emission spectroscopic (OES) analysis of electron temperature and density in atmospheric-pressure non-equilibrium argon plasmas
,” in
3rd Asia-Pacific Conference on Plasma Physics
(
2019
).
40.
H.
Onishi
,
F.
Yamazaki
,
Y.
Hakozaki
,
M.
Takemura
,
A.
Nezu
, and
H.
Akatsuka
, “
Measurement of electron temperature and density of atmospheric-pressure non-equilibrium ar plasma examined with optical emission spectroscopy
,”
Jpn. J. Appl. Phys.
62
(
2
),
026002
(
2021
).
41.
A.
Treshchalov
and
A.
Lissovskii
, “
Spectroscopic diagnostics of a pulsed discharge in high-pressure argon
,”
Quantum Electron.
40
,
234
(
2010
).
42.
U.
Fantz
,
B.
Schalk
, and
K.
Behringer
, “
Calculation and interpretation of the continuum radiation of hydrogen molecules
,”
New J. Phys.
2
,
7
(
2000
).
43.
H.-J.
Kunze
,
Introduction to Plasma Spectroscopy
(
Springer Science & Business Media
,
2009
), Vol.
56
.
You do not currently have access to this content.