Dynamical accelerating structures of thermoionic plasma
The conditions of dynamical accelerating structures of double layer type forming on the edge of thermo-ionic plasma are investigated. Plasma was created by the way of material thermo-evaporation with further ionization under the influence of intensive electron beam. It has been shown that since ther...
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| Zitieren: | Dynamical accelerating structures of thermoionic plasma / I.V. Borgun, D.V. Zinov’ev, D.L. Ryabchikov, I.N. Sereda, A.F. Tseluyko // Вопросы атомной науки и техники. — 2013. — № 4. — С. 61-63. — Бібліогр.: 4 назв. — англ. |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1859482760280801280 |
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| author | Borgun, I.V. Zinov’ev, D.V. Ryabchikov, D.L. Sereda, I.N. Tseluyko, A.F. |
| author_facet | Borgun, I.V. Zinov’ev, D.V. Ryabchikov, D.L. Sereda, I.N. Tseluyko, A.F. |
| citation_txt | Dynamical accelerating structures of thermoionic plasma / I.V. Borgun, D.V. Zinov’ev, D.L. Ryabchikov, I.N. Sereda, A.F. Tseluyko // Вопросы атомной науки и техники. — 2013. — № 4. — С. 61-63. — Бібліогр.: 4 назв. — англ. |
| collection | DSpace DC |
| container_title | Вопросы атомной науки и техники |
| description | The conditions of dynamical accelerating structures of double layer type forming on the edge of thermo-ionic plasma are investigated. Plasma was created by the way of material thermo-evaporation with further ionization under the influence of intensive electron beam. It has been shown that since thermo-ionic plasma forming the double electrical layer of volume charge (DL) creates where the ions of evaporated material (thermo-ions) are accelerate with further possible deposition on substrate. The conditions of intensive thermo-ion flows formation were determined.
Досліджуються умови формування динамічних структур, що прискорюють, типу подвійний шар на фронті термоіонної плазми. Плазма створювалася шляхом термічного випаровування з подальшою іонізацією матеріалу під впливом інтенсивного електронного пучка. Показано, що в міру утворення термоіонної плазми, формується подвійний електричний шар об'ємного заряду (ПШ), в якому відбувається прискорення іонів (термоіонів) матеріалу, який випаровується з подальшим можливим осадженням на підкладці. Визначені умови формування інтенсивних термоіонних потоків.
Исследуются условия формирования динамических ускоряющих структур типа двойной слой на фронте термоионной плазмы. Плазма создавалась путем термического испарения с последующей ионизацией материала под воздействием интенсивного электронного пучка. Показано, что по мере образования термоионной плазмы, формируется двойной электрический слой объемного заряда (ДС), в котором происходит ускорение ионов испаряемого материала (термоионов) с последующим возможным осаждением на подложке. Определены условия формирования интенсивных термоионных потоков.
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ISSN 1562-6016. ВАНТ. 2013. №4(86) 61
NEW METHODS OF CHARGED PARTICLE ACCELERATION
DYNAMICAL ACCELERATING STRUCTURES
OF THERMOIONIC PLASMA
I.V. Borgun, D.V. Zinov’ev, D.L. Ryabchikov, I.N. Sereda, A.F. Tseluyko
V.N. Karazin Kharkov National University, Kharkov, Ukraine
E-mail: igorsereda@mail.ru
The conditions of dynamical accelerating structures of double layer type forming on the edge of thermo-ionic
plasma are investigated. Plasma was created by the way of material thermo-evaporation with further ionization under
the influence of intensive electron beam. It has been shown that since thermo-ionic plasma forming the double electri-
cal layer of volume charge (DL) creates where the ions of evaporated material (thermo-ions) are accelerate with further
possible deposition on substrate. The conditions of intensive thermo-ion flows formation were determined.
PACS: 52.59.Bi, 52.59.Fn
INTRODUCTION
The interest devoted to intensive ion beams forming
is caused first of all by a number of advantages in their
technological application. Not so high ion energy in that
beams helps to reduce inner tensions in got cover, im-
prove adhesion to substrate and pass chemical reactions
on the surface as well. Commonly the vapor of working
substance in vacuum made by its heating with electron
beam with further ionization of evaporated atoms. How-
ever the traditional scheme of electron beam evapora-
tion with external injection of energetic electron beam is
limited by low efficiency of working environment ioni-
zation and problems of beam transportation to a target
as well. In this connection it is offered the alternative
way when the electron beam is forming by the surface
of evaporated material from gas-discharge plasma. Elec-
trons accelerate in electrical field of surface layer,
which appears due to voltage applying between gas-
discharge plasma and a target. Plasma emitter using
excludes the problems of electron beam transportation
that gives an opportunity to electron energy decreasing
to hundreds of electronvolts and allows to create the
counter ion flow of the same energy.
It is experimentally and theoretically shown [1, 2]
that around the target (since surface plasma creating due
to vapor ionization by electron beam) the double electri-
cal layer of volume charge (DL) is forming, which pro-
vides thermo-ions acceleration to the side of a substrate.
Since the DL is dynamical accelerating structure it
makes sense to study this new method of thermo-ion
flow forming for technological application.
1. EXPERIMENTAL SETUP
The experiments of generating intensive thermo-
ionic flow were carried out with help of plasma source
based on the reflective discharge with the filament cath-
ode (Fig. 1). The source was made from water-cooling
discharge tube (1) from stainless steel 40 mm in diame-
ter and 270 mm in length. In the butt end of the tube the
tungsten filament cathode (2) was set. The opposite side
of the tube was connected to a vacuum chamber. As a
cathode-reflector the water-cooled substrate holder (4)
was used. All the system was set in nonuniform longitu-
dinal magnetic field. The magnitude of magnetic field
was chosen in such a way that the electron beam formed
close to filament cathode has a diameter of 20 mm and
expands up to diameter of 200 mm in the treatment area
that allows to create the divergent beam for sample
treatment of high area of surface.
Fig. 1. The scheme of thermo-ionic plasma creation.
1 – discharge tube; 2 – filament cathode; 3 – crucible with metal;
4 – cathode-reflector (treatment surface); 5 – volume charge layer
ϕcol
4
V
z
ϕ (z)
lcat
Vcat
2
+Vt
ϕt
5
3
1
ISSN 1562-6016. ВАНТ. 2013. №4(86) 62
Thermo-ionic plasma was created by the way of
evaporation with further metal ionization put in tungsten
crucible (3). With this aim the positive potential +Vt on
the crucible was applied.
The discharge tube had a galvanic connection with
grounded vacuum chamber and was an anode. It should
be pointed out that in our case the crucible played a role
of second anode with potential on hundreds volts higher
than potential of the main anode of gas-discharge unit.
As a plasma-forming gas argon was used at pressure
about 10-4 Torr.
2. RESULTS AND DISCUSSION
When the crucible heats by electron beam the neu-
tral atom flow from the metal surface is formed, the part
of them is ionized by electron impact. Generated ions
are accelerating by the electric field of layer toward the
electrons, the bipolar current appears. The maximum of
current density through the layer in linear geometry is
determined by Langmuir relation [3].
.i e
e
j m
j M
= (1)
Where ji – the ion current density; je – the electron
current density; те and M – masses of electron and ion
correspondently.
Whereas the electron current density is determined
by the parameters of gas-discharge plasma depended on
the work regime of the plasma source, then the ion cur-
rent density is determined magnitude as well.
As soon as the ion generation velocity by the surface
reaches such a value when generated particle quantity
will exceed the particle one outflew through the layer,
then between volume charge layer and the anode surface
plasma bulk appears. This we called thermo-ionic
plasma and initial layer of negative volume charge
transforms into double electrical layer [4] on the edge of
anode plasma (Fig. 2).
The velocity of particle generation in surface plasma
is determined mainly by neutral atoms concentration of
evaporated substance in surface layer, which in its turn
depends on the crucible temperature.
With the evolution of the evaporation and ionization
processes since not all generated ions can go trough the
layer due to current conductive limiting, DL will expand
from the crucible surface owing to gas-kinetic pressure.
In case of constant voltage supplied on the crucible
the DL expansion is accompanied with increasing of
outer layer surface, electron beam power and the cruci-
ble temperature.
The crucible temperature increasing causes rising of
substance evaporation velocity, enhancing neutral atoms
concentration by the surface and increasing of charged
particles generation velocity. It leads to volume of sur-
face plasma bulk raising and as a consequence to further
DL expansion from the crucible, area increasing and
current on the crucible raising.
This process will continue as long as there is no vio-
lation of the relation (1), which will lead to a break the
conditions of DL existence. It limits the heating of the
crucible, the temperature decreases, neutral atoms con-
centration drops rapidly and the generation of surface
plasma stops. Only when restoring the original condi-
tions the process is repeating. In this case there is a
pulse mode, which is not always suitable for industrial
purposes.
Fig. 2. The scheme of double layer formation
on the edge of thermo-ionic plasma.
1 – crucible; 2 – thermo-ionic plasma
The results of ion flow dynamics investigation from
the crucible and dynamics of the active power spent on
its heating are shown in Fig. 3 as the oscillograms of
crucible voltage and current, the collector current and
the full ion current of the sample surface. The collector
with area about 1 cm2 was set on the treated surface.
Fig. 3.The oscillograms of voltage on the crucible Vcr
crucible current Icr, current density on collector jкол and
whole ion current Ii at average crucible current of 1,5 А
One can see that since dense thermo-ionic plasma
expanding the crucible current Icr and voltage Vcr are
increase. In this regime dotted in Fig. 2 monolayer ex-
ists. The forming of double layer takes priority over the
development of intense HF-oscillations concerned with
beam-plasma instability. In the moment of the DL form-
-0.010 -0.005 0.000 0.005 0.010
0
100V cr
, В
Time, [s]
-0.010 -0.005 0.000 0.005 0.010
-0.5
0.0
0.5
1.0
I cr
, [
А
]
Time, [s]
-0.010 -0.005 0.000 0.005 0.010
-10
-5
0
5
j co
ll,
m
А
Time, [s]
-0.010 -0.005 0.000 0.005 0.010
-4
-3
-2
-1
0
1
2
I i,
A
Time, [s]
ϕt1
ϕt2
ϕ (z)
z
+Vt
1
2
Iti Iti
ISSN 1562-6016. ВАНТ. 2013. №4(86) 63
ing (see solid line in Fig. 2) the crucible current Icr
sharply raises (the crucible voltage is reduced), becomes
more than the discharge current Id and the DL is de-
stroyed.
The rapid change of the crucible current sign Icr in-
dicates on the starting of crucible reheating processes
for the dense surface plasma forming. Then the process
is repeated cyclically.
On the treatment surface mainly electron current
goes, and only at the moment of double layer creating
the electron current changes on the ion one. Thus, the
regime of thermo-ionic-deposition in this system is car-
ried out in a pulse mode at the time of double layer
forming on the edge of thermo-ionic plasma.
It should be pointed out the following. Accordingly
(1) the electron current through the layer must be suffi-
ciently higher than ion one. However in our experiments
(see Fig. 3) the electron current on collector jкол has the
same order of magnitude with ion one. The authors have
obstructed to make the explanation to observed phe-
nomena yet.
CONCLUSIONS
Thus, forming and acceleration of charged particles
beams occurs due to dynamical DL forming on the edge
of thermo-ionic plasma. Plasma is created owing to ma-
terial thermo-evaporation with further ionization under
intensive electron beam influence formed by the surface
of evaporated material in the volume charge layer. It has
been shown, that forming and accelerating of ion flow
in the system are in pulse mode at the moment of DL
forming on the edge of thermo-ionic plasma when elec-
tron current on a target changes on ion one.
REFERENCES
1. D.V. Zinov’ev, A.F. Tseluyko, N.N. Yunakov.
Thermo-ionic layer deposition in reflective arc dis-
charge // Bulletin of Kharkov National University.
Series physical “Nuclei, particles, fields”. 1998,
№ 421, p. 56-61 (in Russian).
2. D.V. Zinov’ev, A.F. Tseluyko, N.N. Yunakov. Dou-
ble layer stabilization on the edge of gas-discharge
and thermo-ionic plasma // Fly-space technique and
technology. 2008, № 10(57), p. 20-27 (in Rrussian).
3. V.L. Granovskiy. Electrical current in gas. Mos-
cow: “Nauka”, 1971, p. 338-340.
4. L.P. Block. Potential double layer in the ionosphere
// Cosmic Electrodun. 1972, № 2, v. 3, p. 349-376.
Article received 29.03.2013.
ДИНАМИЧЕСКИЕ УСКОРЯЮЩИЕ СТРУКТУРЫ ТЕРМОИОННОЙ ПЛАЗМЫ
Е.В. Боргун, Д.В. Зиновьев, Д.Л. Рябчиков, И.Н. Середа, А.Ф. Целуйко
Исследуются условия формирования динамических ускоряющих структур типа двойной слой на фронте
термоионной плазмы. Плазма создавалась путем термического испарения с последующей ионизацией мате-
риала под воздействием интенсивного электронного пучка. Показано, что по мере образования термоионной
плазмы, формируется двойной электрический слой объемного заряда (ДС), в котором происходит ускорение
ионов испаряемого материала (термоионов) с последующим возможным осаждением на подложке. Опреде-
лены условия формирования интенсивных термоионных потоков.
ДИНАМІЧНІ ПРИСКОРЮЮЧІ СТРУКТУРИ ТЕРМОІОННОЇ ПЛАЗМИ
Є.В. Боргун, Д.В. Зінов’єв, Д.Л. Рябчиков, І.М. Середа, О.Ф. Целуйко
Досліджуються умови формування динамічних структур, що прискорюють, типу подвійний шар на фро-
нті термоіонної плазми. Плазма створювалася шляхом термічного випаровування з подальшою іонізацією
матеріалу під впливом інтенсивного електронного пучка. Показано, що в міру утворення термоіонної плаз-
ми, формується подвійний електричний шар об'ємного заряду (ПШ), в якому відбувається прискорення іонів
(термоіонів) матеріалу, який випаровується з подальшим можливим осадженням на підкладці. Визначені
умови формування інтенсивних термоіонних потоків.
|
| id | nasplib_isofts_kiev_ua-123456789-111913 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1562-6016 |
| language | English |
| last_indexed | 2025-11-24T14:39:29Z |
| publishDate | 2013 |
| publisher | Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| record_format | dspace |
| spelling | Borgun, I.V. Zinov’ev, D.V. Ryabchikov, D.L. Sereda, I.N. Tseluyko, A.F. 2017-01-15T15:01:04Z 2017-01-15T15:01:04Z 2013 Dynamical accelerating structures of thermoionic plasma / I.V. Borgun, D.V. Zinov’ev, D.L. Ryabchikov, I.N. Sereda, A.F. Tseluyko // Вопросы атомной науки и техники. — 2013. — № 4. — С. 61-63. — Бібліогр.: 4 назв. — англ. 1562-6016 PACS: 52.59.Bi, 52.59.Fn https://nasplib.isofts.kiev.ua/handle/123456789/111913 The conditions of dynamical accelerating structures of double layer type forming on the edge of thermo-ionic plasma are investigated. Plasma was created by the way of material thermo-evaporation with further ionization under the influence of intensive electron beam. It has been shown that since thermo-ionic plasma forming the double electrical layer of volume charge (DL) creates where the ions of evaporated material (thermo-ions) are accelerate with further possible deposition on substrate. The conditions of intensive thermo-ion flows formation were determined. Досліджуються умови формування динамічних структур, що прискорюють, типу подвійний шар на фронті термоіонної плазми. Плазма створювалася шляхом термічного випаровування з подальшою іонізацією матеріалу під впливом інтенсивного електронного пучка. Показано, що в міру утворення термоіонної плазми, формується подвійний електричний шар об'ємного заряду (ПШ), в якому відбувається прискорення іонів (термоіонів) матеріалу, який випаровується з подальшим можливим осадженням на підкладці. Визначені умови формування інтенсивних термоіонних потоків. Исследуются условия формирования динамических ускоряющих структур типа двойной слой на фронте термоионной плазмы. Плазма создавалась путем термического испарения с последующей ионизацией материала под воздействием интенсивного электронного пучка. Показано, что по мере образования термоионной плазмы, формируется двойной электрический слой объемного заряда (ДС), в котором происходит ускорение ионов испаряемого материала (термоионов) с последующим возможным осаждением на подложке. Определены условия формирования интенсивных термоионных потоков. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Новые методы ускорения заряженных частиц Dynamical accelerating structures of thermoionic plasma Динамічні прискорюючі структури термоіонної плазми Динамические ускоряющие структуры термоионной плазмы Article published earlier |
| spellingShingle | Dynamical accelerating structures of thermoionic plasma Borgun, I.V. Zinov’ev, D.V. Ryabchikov, D.L. Sereda, I.N. Tseluyko, A.F. Новые методы ускорения заряженных частиц |
| title | Dynamical accelerating structures of thermoionic plasma |
| title_alt | Динамічні прискорюючі структури термоіонної плазми Динамические ускоряющие структуры термоионной плазмы |
| title_full | Dynamical accelerating structures of thermoionic plasma |
| title_fullStr | Dynamical accelerating structures of thermoionic plasma |
| title_full_unstemmed | Dynamical accelerating structures of thermoionic plasma |
| title_short | Dynamical accelerating structures of thermoionic plasma |
| title_sort | dynamical accelerating structures of thermoionic plasma |
| topic | Новые методы ускорения заряженных частиц |
| topic_facet | Новые методы ускорения заряженных частиц |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/111913 |
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