Inversion of the Electron Energy Distribution in Hollow Cathode Glow Discharge in Nitrogen-Sulfur Hexafluoride Gas Mixture
I.A.Soloshenko, V.Yu.Bazhenov, V.A.Khomich, V.V.Tsiolko, A.F.Tarasenko,
A.G.Terent’eva, A.G.Kalyuzhnaya, A.I.Shchedrin
Institute of Physics NAS Ukraine, pr. Nauki 46, 03022, Kiev, Ukraine,
Abstract
Experimental and theoretical studies of the electron energy distribution function (EEDF) in glow discharge with hollow cathode in the mixture of N2 and SF6 are accomplished. It is shown that at adding of 5-6% SF6 to nitrogen, electron concentration at inverse region of EEDF (2-4 eV) increases by about one order of magnitude. The reason for such effect consists in intensive adherence of low-energy electrons to electronegative molecules which promotes the decrease of their amount in the discharge and, consequently, the increase of relative amount of electrons in the inverse region.
 (a044p.pdf, 178 840 Bytes)
Component Content of Active Particles in Plasma-Chemical Reactor Based on a Volume Barrier Discharge
I.A.Soloshenko1, V.V.Tsiolko1, S.S.Pogulay1, A.G.Terent’eva1, V.Yu.Bazhenov1, A.I.Shchedrin1, A.V.Ryabtsev1, A.I.Kuzmichev2
1Institute of Physics NAS Ukraine, pr. Nauki 46, 03022, Kiev, Ukraine,
2Dept. Electron Device, National Technical University of Ukraine “Kiev Polytechnical Institute”, Kiev, Ukraine
Abstract
In this proceeding the results of theoretical and experimental studies of the component content of active particles formed in plasma-chemical reactor composed of multiple-cell generator of active particles based on volume barrier discharge, and working chamber are presented. For calculation of the content of uncharged plasma components an approach is proposed which is based on averaging of introduced power over the entire volume. Advantages of such approach consist in absence of fitting parameters, such as dimensions of microdischarges, their surface density, and rate of breakdowns. The calculation and the experiment were accomplished with the use of dry air (20% relative humidity) as plasma generating medium. Concentrations of O3, HNO3, HNO2, N2O5, and NO3 were measured experimentally in the discharge volume and working chamber for transient time of the particles on the discharge of 0.3 s and more, and the discharge specific power of 1.5 W/cm3. It has been determined that the best agreement between the calculation and the experiment occurs at calculated gas medium temperature in the discharge plasma of about 400 - 425 K, which corresponds to experimentally measured rotational temperature of nitrogen. In the most cases calculated concentrations of O3, HNO3,
HNO2, N2O5, and NO3 for barrier discharge and working chamber are in a good agreement with respective measured values.
(d003.pdf, 193 191 Bytes)
Utilization of Ultraviolet Radiation of Cold Hollow Cathode Glow Discharge Plasma for Water Disinfection
I.A.Soloshenko1, V.Yu.Bazhenov1, V.A.Khomich1, V.V.Tsiolko1,
N.G.Potapchenko2, V.V.Goncharuk2
1Institute of Physics NAS Ukraine, pr. Nauki 46, 03022, Kiev, Ukraine,
2Institute of Colloid and Water Chemistry of National Academy of Sciences of Ukraine, 42 Academician Vernadsky Blvd., 03680, Kiev, Ukraine.
Abstract
In this proceeding the results of experimental studies of peculiarities of Escherichia coli water suspension inactivation by ultraviolet radiation of hollow cathode discharge plasma in different gaseous media are presented. It is shown that efficiency of the inactivation by the discharges on oxygen, mixtures of oxygen with deuterium, and water vapor is essentially higher than that by the discharge on air, as well as the discharges of low and medium pressure mercury lamps.
(d016p.pdf, 184 388 Bytes)
Inversion of the Electron Energy Distribution in Hollow-Cathode Glow Discharge in Nitrogen–Sulfur Hexafluoride Gas Mixture
V. Yu. Bazhenov, A. G. Kalyuzhnaya, I. A. Soloshenko, A. F. Tarasenko,
A. G. Terent’eva, V. V. Tsiolko, and A. I. Shchedrin
Institute of Physics NAS Ukraine, pr. Nauki 46, 03022, Kiev, Ukraine,
Abstract
The electron energy distribution function (EDF) in a hollow-cathode glow discharge in nitrogen– sulfur hexafluoride (N2–SF6) gas mixture has been studied by experimental and theoretical methods. On adding a small amount of SF6to N2, the density of electrons in the energy interval (2–4 eV) of the EDF inversion increases by approximately one order of magnitude.
(tepl922.pdf, 188 420 Bytes)
Theoretical and experimental investigation of the component content of active particles generated by barrier discharge in dry and wet air in the remote chamber
I.A Soloshenko1, V.V.Tsiolko1, V.Yu. Bazhenov1, A.G. Terentyeva1,
A.I. Shchedrin1, A.V. Ryabtsev1, A.I. Kuzmichev2
1Institute of Physics NAS Ukraine, pr. Nauki 46, 03022, Kiev, Ukraine,
22Dept. Electron Device, National Technical University of Ukraine “Kiev Polytechnical Institute”, Kiev, Ukraine
Abstract
In the present work detailed theoretical and experimental studies of the plasma-chemical reactor, which consists of two parts: 1) generator of active particles based on volume barrier discharges; 2) work chamber, are accomplished for widely used plasma generating medium – dry and wet air. It is shown that the essential amount of active molecules, such as O3, H2O2, N2O5, HNO3, HNO2, NO3, is possible in work chamber volume with concentrations depending on flow rate and water vapor percentage.
(bardis.pdf, 218 385 Bytes)
Features of Sterilization Using Low Pressure DC Discharge Hydrogen Peroxide Plasma
I.A Soloshenko1, V.V.Tsiolko1, V.A.Khomich1,
V.Yu.Bazhenov1, A.V.Ryabtsev1, A.I.Schedrin1,
I.L.Mikhno2
1Institute of Physics NAS Ukraine, pr. Nauki 46, 03022, Kiev, Ukraine,
2Institute of Epidemiology and Infective Diseases, st. Protasov Yar, 03038, Kiev, Ukraine
Abstract
This investigation studies the theoretical and practical features of sterilization using glow discharge plasma in hydrogen peroxide vapor. It is determined that, in such a system, most sterilization is performed by active particles formed in the plasma, rather than by ultraviolet (UV) radiation (as is the case in gas discharges like air and oxygen). This study shows that sterilization by discharge plasma in hydrogen peroxide vapor is more efficient than sterilization by plasma of the discharge in gases: sterilization time is 2-3 times shorter in open surfaces and 10 times shorter in packed articles. This study’s calculations indicate that this enhanced efficiency might be due to fact that concentrations of the main biologically active particles, such as atomic oxygen and oxygen molecules excited to lower metastable states, reach values of ~1014-1015 cm-3, which is 2-3 order of magnitude higher than that in oxygen plasma at the same parameters of the discharge.
Index words: plasma, discharge, hydrogen peroxide, sterilization.
(features.pdf, 428 273 Bytes)
KINETIC PROCESSES IN A PLASMA OF BARRIER DISCHARGE ON ATMOSPHERIC AIR: INFLUENCE OF WATER VAPOR ON BIOLOGICAL ACTIVITY OF GENERATED MEDIUM
V.Yu. Bazhenov1, A.V. Ryabtsev1, I.A. Soloshenko1,
V.A. Khomich1, V.V. Tsiolko1,
A.I. Shchedrin1, A. I. Kuzmichev2,
V.I. Kryzhanovsky2, I. L. Mihno3.
1Institute of Physics NAS of Ukraine, pr. Nauki 46, 03022, Kiev, Ukraine, tsiolko@iop.kiev.ua
2National Technical University of Ukraine “Kiev Polytechnical Institute”, pr. Peremogy 37, KPI-2230, 03056, Kiev, Ukraine
3 Institute of Epidemiology and Infective Diseases, st. Protasov Yar 4, 03038, Kiev, Ukraine
Abstract
In the present paper theoretical and experimental investigations of the water vapor influence on the biological activity of the medium generated by barrier discharge on atmospheric air were performed. Numerical calculation of the component composition of the particles generated by barrier discharge in dry and moisture air shown that moistening the air on the one hand results in the ozone concentration reduction, but on the other hand it results in increase of the concentration of the such biologically active particle as N2O4 and formation of the new active particles – molecules of hydrogen peroxide H2O2, nitric HNO3 and nitrous HNO2 acids, and HO2NO2
radicals in the discharge. Experiments on the spores processing have shown that moistening of air leads to increase of the biological activity of the medium generated by barrier discharge. On basis of experiments and theoretical calculation one can insists that the rise of the medium activity is connected with generation of the hydric particles H2O2, HNO3, HNO2 and HO2NO2.
(kinetic.pdf, 233 864 Bytes)
Investigation of the Electron Energy Distribution Function in Hollow-Cathode Glow Discharges in Nitrogen and Oxygen
V.
Yu. Bazhenov, A. V. Ryabtsev, I. A. Soloshenko, A. G. Terentyeva, V. A. Khomich, V. V. Tsiolko, and A. I. Shchedrin
Institute of Physics of NAS of Ukraine, pr. Nauki 46, Kiev, 03022, Ukraine
Abstract—The mechanism for the formation of the inverse electron distribution function is proposed and real-ized experimentally in a nitrogen plasma of a hollow-cathode glow discharge. It is shown theoretically and experimentally that, for a broad range of the parameters of an N 2 discharge, it is possible to form a significant dip in the profile of the electron distribution function in the energy range e = 2–4 eV and, accordingly, to pro-duce the inverse distribution with df(e)/de > 0. The formation of a dip is associated with both the vibrational excitation of N 2 molecules and the characteristic features of a hollow-cathode glow discharge. In such a dis-charge, the applied voltage drops preferentially across a narrow cathode sheath. In the main discharge region, the electric
field E is weak (E < 0.1 V/cm at a pressure of about p ~ 0.1 torr) and does not heat the discharge plasma. The gas is ionized and the
ionization-produced electrons are heated by a beam of fast electrons (with an energy of about 400 eV) emitted from the cathode. A high-energy
electron beam plays an important role in the formation of a dip in the profile of the electron distribution function in the energy
range in which the cross section for the vibrational excitation of nitrogen molecules is maximum. A plasma with an inverted electron
distribution function can be used to create a population inversion in which more impurity molecules and atoms will exist in electronically
excited states.
(pub08.pdf, 191
100 Bytes)
 |
|
Investigation
of the sterilization of medical instruments by atmospheric pressure
discharges
V.Yu. Bazhenov1, A.I. Kuzmichev2,
V.I. Kryzhanovsky2, I.L. Mihno3, A.V. Ryabtsev1,
I.A. Soloshenko1,
V.A. Khomich1, V.V. Tsiolko1, A.I. Shchedrin1
1Institute of Physics NAS of Ukraine,
pr. Nauki 46, 03022, Kiev, Ukraine
2National Technical University of Ukraine "Kiev Polytechnical Institute",
pr. Peremogy 37, KPI-2230, 03056, Kiev, Ukraine
3 Institute of Epidemiology and Infective Diseases, st. Protasov
Yar 4, 03038, Kiev, Ukraine
Abstract In the present proceedings
the experimental and theoretical investigations of sterilization
of medical instruments by a barrier discharges were performed. It
is shown that moistening the air results in essential growth of
sterilization efficiency, and this effect may be due to formation
of hydrogen peroxide H2O2, nitric HNO3 and
nitrous HNO2 acids, HO2NO2
radicals and such biologically active particles as N2O4
and N2O5 in the discharge.
(pub05.zip, 64
377 Bytes)
Investigation
of the electron distribution function in the glow discharge with
hollow cathode
V.Yu. Bazhenov, A.V. Ryabtsev, I.A.
Soloshenko, A.G. Terentyeva, V.V. Tsiolko, A.I. Shchedrin
Institute of Physics of NAS of Ukraine,
pr. Nauki 46, Kiev, 03022, Ukraine
Abstract In the present proceeding
experimental and theoretical studies of electron energy distribution
function in stationary glow discharge with hollow cathode in nitrogen
and oxygen are performed. It is shown that in such discharge in
nitrogen in energy range E = 2 ... 4 eV significant gap and respective
inverse region appears on the EDF, which is due to vibrational excitation
of N2 molecules. On the contrary, in oxygen the electron distribution
function is monotonous due to its cutoff by the processes of excitation
of lower metastable electron levels of O2 having low threshold energy,
and also due to small excitation cross section for vibrational levels
of oxygen molecule.
(pub06.zip, 156
397 Bytes)
Sterilization
by plasma of the low pressure discharge glowing in hydrogen peroxide
vapor
I.A Soloshenko1,
V.V.Tsiolko1, V.A.Khomich1,
V.Yu. Bazhenov1, A.V.Ryabtsev1, A.I.Shchedrin1,
I.L.Mikhno2
1Institute of Physics NAS Ukraine,
pr. Nauki 46, 03022, Kiev, Ukraine,
2Institute of Epidemiology and Infective Diseases, st. Protasov
Yar, 03038, Kiev, Ukraine
Abstract In the present proceedings
the experimental and theoretical investigations of the features
of sterilization by plasma of glow discharge in hydrogen peroxide
vapor were performed. It is determined that in such system main
role in sterilization is performed by active particles, rather than
by UV radiation of the plasma (as it does in case of discharge in
gases, particularly, air and oxygen). It is shown that efficiency
of sterilization by discharge plasma in hydrogen peroxide vapor
is higher than that by plasma of the discharge in gases – sterilization
time of open surface is 2-3 times shorter, and that of sterilization
of packed articles is shorter by factor about 10. Accomplished calculations
of the plasma component content in the discharge in hydrogen peroxide
have shown that sterilization efficiency enhancement can be due
to fact that concentrations of such biologically active particles,
as atomic oxygen and oxygen molecules excited to lower metastable
states, reach value of ~ 1014...1015 cm-3, which is 2-3 orders of
magnitude higher than that in oxygen plasma at the same parameters
of the discharge.
(pub07.zip, 132
889 Bytes)
|
|
Sterilization of Medical Products
in Low-Pressure Glow Discharges
I. A. Soloshenko*, V.
V. Tsiolko*, V. A. Khomich*, A. I. Shchedrin*, A. V. Ryabtsev*,
V. Yu. Bazhenov*, and I. L. Mikhno**
*Institute of Physics, National Academy
of Sciences of Ukraine, pr. Nauki 46, Kiev, 03039 Ukraine
**Institute of Epidemiology and Infectious Diseases, Ministry of
Health of Ukraine, Ukraine
Abstract. Results are presented
from experimental and theoretical studies of the sterilization of
medical products by the plasmas of dc glow discharges in different
gas media. The sterilization efficiency is obtained as a function
of discharge parameters. The plasma composition in discharges in
N2 and O2 is investigated under the operating conditions of a
plasma sterilizer. It is shown that free surfaces of medical products
are sterilized primarily by UV radiation from the discharge plasma,
while an important role in sterilization of products with complicated
shapes is played by such chemically active particles as oxygen atoms
and electronically excited O2 molecules.
© 2000 MAIK “Nauka/ Interperiodica”.
(pub04.pdf, 194
482 Bytes)
EXPERIMENTAL
AND THEORETICAL INVESTIGATION OF COLD STERILIZATION OF MEDICAL INSTRUMENTS BY PLASMA DC
GLOW DISCHARGE
I.O.Soloshenko 1, V.A.Khomich 1, V.V.Tsiolko 1, I.L.Mikhno 2, A.I.Shchedrin 1, A.V.Ryabtsev 1, V.Yu.Bazhenov 1
1
Institute of Physics NAS of Ukraine, pr. Nauki 46, Kiev, 03039, Ukraine.
2 Institute of Epidemiology and Infective Diseases, st. Protasov Yar 4, Kiev,
252038, Ukraine.
Abstract. This report
presents both the results of experimental investigation of the features of sterilization
by plasma DC glow discharge: a) dependencies of the efficiency of plasma sterilization on
discharge parameters; b) ratio between main sterilization factors (charged particles,
neutral chemical active particles and ultraviolet (UV) radiation), and the results of
numerical simulation of component composition.
(pub01.zip,
35 547 Bytes)
COLD
STERILIZATION OF MEDICAL DEVICES AND MATERIALS BY PLASMA DC GLOW DISCHARGE
A.V.Khomich 1, I.A.Soloshenko 1, V.V.Tsiolko 1, I.L.Mikhno 2
1 Institute
of Physics NAS Ukraine, pr.Nauki 46, 252022, Kiev, Ukraine
2 Institute of Epidemiology and Infective Diseases, sp.Protasov
Yar 4, 252038, Kiev, Ukraine
ABSTRACT This report presents
the results of investigation the efficiency of sterilization of medical devices directly
in the plasma of DC glow discharge. Sterilization regime is independent on the discharge
chamber loading by processed instruments. It is shown that effective sterilization is
reached using either air or other gases (argon, nitrogen, oxygen) with comparatively low
power density (0.003 - 0.03 W/cm3). Sterilization time comprises less than 10 minutes.
Temperature of the processed instruments does not exceed 650C. Usage of this discharge
results in essential simplifying of the sterilizer, lowering its cost and increasing its
safety for servicing personnel and also improvement of its operational characteristics in
comparison with the devices utilizing RF or VHF discharges.
( pub02.zip,
19 286 Bytes)
INVESTIGATION OF PRINCIPAL FACTORS OF THE STERILIZATION BY PLASMA DC GLOW DISCHARGE
V.A.Khomich 1, I.A.Soloshenko 1, V.V.Tsiolko 1, I.L.Mikhno 2
1 Institute of Physics
NAS Ukraine, Pr.Nauki 46, 252650 Kiev-22, Ukraine
2 Institute of Epidemiology and Infective Diseases, sp.Protasov Yar 4, 252038,
Kiev, Ukraine
Abstract. This report
presents the results of investigation the factors of the sterilization of medical devices
directly in the plasma of DC glow discharge. The researches have provided convincing
evidence that main sterilization factor is presented by ultraviolet radiation of the
plasma in wavelength range of 160 nm - 240nm for opened surface and active electroneutral
particles for the instruments with complex shape or long narrow tubes. It is shown that
effective sterilization is possible using either air or other gases (argon, nitrogen,
oxygen, carbon dioxide, hydrogen) with comparatively low power density (Wd=0,003
(0,03W/cc).
(pub03.zip,
16 216 Bytes)
|
