Microwave generation by supercritical REB at plasma assistance
The experimental researches on generation of microwave radiation in a system with a supercritical current of a relativistic electron beam produced in the magnetically isolated diode and external plasma source are carried out. The researches have shown that in the presence of external plasma the po...
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2004
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| Цитувати: | Microwave generation by supercritical REB at plasma assistance / P.T. Chupikov, I.N. Onishchenko, Yu.V. Prokopenko, S.S. Pushkarev, A.M. Yegorov // Вопросы атомной науки и техники. — 2004. — № 2. — С. 158-160. — Бібліогр.: 3 назв. — англ. |
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irk-123456789-793782015-04-01T03:02:19Z Microwave generation by supercritical REB at plasma assistance Chupikov, P.T. Onishchenko, I.N. Prokopenko, Yu.V. Pushkarev, S.S. Yegorov, A.M. Динамика пучков The experimental researches on generation of microwave radiation in a system with a supercritical current of a relativistic electron beam produced in the magnetically isolated diode and external plasma source are carried out. The researches have shown that in the presence of external plasma the power of microwave radiation is increased in comparison to vacuum system. Проведені експериментальні дослідження генерації НВЧ випромінювання в системі з надкритичним струмом релятивістського електронного пучка і зовнішнім плазмовим джерелом. Дослідження показали, що при наявності зовнішньої плазми потужність НВЧ випромінювання збільшується в порівняні з вакуумною системою. Проведены экспериментальные исследования генерации СВЧ излучения в системе со сверхкритическим током релятивистского электронного пучка и внешним плазменным источником. Исследования показали, что при наличии внешней плазмы мощность СВЧ излучения увеличивается по сравнению с вакуумной системой. 2004 Article Microwave generation by supercritical REB at plasma assistance / P.T. Chupikov, I.N. Onishchenko, Yu.V. Prokopenko, S.S. Pushkarev, A.M. Yegorov // Вопросы атомной науки и техники. — 2004. — № 2. — С. 158-160. — Бібліогр.: 3 назв. — англ. 1562-6016 PACS: 52.40.Mj http://dspace.nbuv.gov.ua/handle/123456789/79378 en Вопросы атомной науки и техники Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine |
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English |
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Динамика пучков Динамика пучков |
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Динамика пучков Динамика пучков Chupikov, P.T. Onishchenko, I.N. Prokopenko, Yu.V. Pushkarev, S.S. Yegorov, A.M. Microwave generation by supercritical REB at plasma assistance Вопросы атомной науки и техники |
| description |
The experimental researches on generation of microwave radiation in a system with a supercritical current of a
relativistic electron beam produced in the magnetically isolated diode and external plasma source are carried out.
The researches have shown that in the presence of external plasma the power of microwave radiation is increased in
comparison to vacuum system. |
| format |
Article |
| author |
Chupikov, P.T. Onishchenko, I.N. Prokopenko, Yu.V. Pushkarev, S.S. Yegorov, A.M. |
| author_facet |
Chupikov, P.T. Onishchenko, I.N. Prokopenko, Yu.V. Pushkarev, S.S. Yegorov, A.M. |
| author_sort |
Chupikov, P.T. |
| title |
Microwave generation by supercritical REB at plasma assistance |
| title_short |
Microwave generation by supercritical REB at plasma assistance |
| title_full |
Microwave generation by supercritical REB at plasma assistance |
| title_fullStr |
Microwave generation by supercritical REB at plasma assistance |
| title_full_unstemmed |
Microwave generation by supercritical REB at plasma assistance |
| title_sort |
microwave generation by supercritical reb at plasma assistance |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2004 |
| topic_facet |
Динамика пучков |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/79378 |
| citation_txt |
Microwave generation by supercritical REB at plasma assistance / P.T. Chupikov, I.N. Onishchenko, Yu.V. Prokopenko, S.S. Pushkarev, A.M. Yegorov // Вопросы атомной науки и техники. — 2004. — № 2. — С. 158-160. — Бібліогр.: 3 назв. — англ. |
| series |
Вопросы атомной науки и техники |
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| first_indexed |
2025-07-06T03:26:49Z |
| last_indexed |
2025-07-06T03:26:49Z |
| _version_ |
1836866506090086400 |
| fulltext |
MICROWAVE GENERATION BY SUPERCRITICAL REB
AT PLASMA ASSISTANCE
P.T. Chupikov, I.N. Onishchenko, Yu.V. Prokopenko, S.S. Pushkarev, A.M. Yegorov
NSC "Kharkov Institute of Physics and Technology"
Akademicheskaya St, 1, Kharkov – 61108, Ukraine
E-mail: onish@kipt.kharkov.ua
The experimental researches on generation of microwave radiation in a system with a supercritical current of a
relativistic electron beam produced in the magnetically isolated diode and external plasma source are carried out.
The researches have shown that in the presence of external plasma the power of microwave radiation is increased in
comparison to vacuum system.
PACS: 52.40.Mj
1. INTRODUCTION
The structure with a virtual cathode (VC) is in the
first section of a collective ion accelerator based on si-
multaneous temporal and spatial modulation of a rela-
tivistic electron beam (REB) [1, 2]. In this section, the
low frequency modulation of supercritical high current
REB is caused by periodic compensation of VC by ions
of an external plasma source and the ion flow is formed
in an electrical field of VC. Confirmation of existence
of VC in electrodynamic structure is the generation of
microwave radiation. The low frequency modulation of
microwave radiation corresponds to the time modulation
of REB.
2. MICROWAVE GENERATOR
Fig.1 shows the structure of a microwave generator
that was realized in the first section of a collective ion
accelerator, in which the electron accelerator “Agat”
forms the REB with energy 210 keV with apulse current
duration of 0.8 µs. The total energy of the Marx genera-
tor (MG) is equal to 0.9 kJ when each stage is charged
by voltage of 30 kV.
5
4
VC
1 6
2
7 8
3
MG ASCS EMFF
Fig. 1 Schematic diagram of experimental installa-
tion
1 – cathode; 2 – anode; 3 – plasma source;
4 – drift chamber; 5 – horn; 6 – solenoid;
7 – Rogovsky coil; 8 – voltage divider
VC – virtual cathode; MG – Marx generator;
ASCS – accelerator starting and control system;
EMFF – external magnetic field formation
The MG high-voltage pulse is applied to the magnet-
ically-insulated diode. The cylindrical cathode is made
from stainless steel and has diameter of 30 mm and
depth of an emission edge of 0.1 mm.
The tubular electron beam has been formed by the
magnetron type diode. The emission current value of the
electron beam equal to 4.4 kA was determined by the
diameter of input cylindrical anode equal to 40 mm. The
inner diameter of the drift electron cylindrical chamber
was equal to 50 mm. The jumping of electrodynamic
structure was necessary for formation of the virtual
cathode. In such a system the limiting vacuum current
of an electron beam had the value of 3.4 kA.
The electron beam was conveyed by a longitudinal
external magnetic field of the solenoid with inductance
of 810 µH and maximally possible induction up to
1.33 T that was supplied by the system of external mag-
netic field formation. The period of the external magnet-
ic field was of 11.4 ms. In the cathode region the induc-
tion value of magnetic field has quantity ~60% from in-
duction value inside the solenoid. Such configuration of
the magnetic field formed the electron cylindrical beam
with diameter of 30 mm and wall thickness of 3 mm in
the liner.
The control and measurement of parameters of the
high-current electron accelerator were made by a high-
voltage divider and induction sensor of a current used
on the input current-conductor of magnetically-insulated
diode (Fig.1). The induction of the external magnetic
field of solenoid was measured by the induction-mag-
netic probe. The division factor equal to 6.8×103 due to
the MG activity in aperiodic regime was selected from a
condition of signal registration on broadband TDS224
oscillograph with the use of a low-voltage divider,
which had the input and output resistance of 50 Ohm.
3. FORMATION OF VIRTUAL CATHODE
The conditions of virtual cathode formation in the
diode with magnetic insulation were studied using the
cylindrical electrodynamic structures. Structures of two
types: the circular tube of diameter 41 mm and the
waveguide with jumping namely "diode anodic unit of
diameter 41 mm that jumped in cylindrical drift liner of
a greater diameter 50 mm" were investigated experi-
mentally. In Fig.2 the oscillograms of the diode input
current and the REB current on the collector (Faraday
cup) are shown. As it is seen from Fig.2,a that in the
first case the REB current injected from the cylindrical
cathode was transported practically without losses to the
collector placed at the end of the drift liner and in the
homogeneous constant magnetic field with induction
0.88 T. In the electrodynamic structure with jumping,
the REB current on the collector was much less, than
the diode input current and corresponded to value of a
___________________________________________________________
PROBLEMS OF ATOMIC SIENCE AND TECHNOLOGY. 2004. № 2.
Series: Nuclear Physics Investigations (43), p.158-160. 158
mailto:onish@kipt.kharkov.ua
space charge limiting vacuum current in the drift liner
(Fig.2,b). It proved the possibility of the virtual cathode
formation in the structure with jumping.
-500,0n 0,0 500,0n 1,0µ 1,5µ 2,0µ
-6
-5
-4
-3
-2
-1
0
2
1
C
ur
re
nt
, k
A
Time, s
a)
-500,0n 0,0 500,0n 1,0µ 1,5µ 2,0µ
-6
-5
-4
-3
-2
-1
0
2
1
C
ur
re
nt
, k
A
Time, s
b)
Fig.2. Current oscillograms
1 – the diode input current;
2 – the collector current of REB
4. PLASMA ANODE
The plasma anode was formed by a plasma source
consisting of four plasma guns with breakdown on a di-
electric surface. The guns were placed uniformly on pe-
ripherals of the drift chamber (Fig.3) in the region up to
the virtual cathode (Fig.1). The start unit (1) performed
their synchronous start. In each gun, the voltage break-
downs on an organic glass surface in vacuum of pres-
sure 2×10-4 Torr were provided by voltage pulses with
maximum values of 12 kV and durations of 6 µs. These
pulses were formed by aperiodic discharge of con-
densers of capacity 0.25 µF that were charged by the
charge unit (2). The Ampere force caused by the own
magnetic field of the surface electric discharge loop cir-
cuit has provided initial radial motion of plasma to the
liner axis of the ion accelerator under elaboration.
1
2
Fig. 3. The structure scheme of plasma source and
its supply
1 – start unit; 2 – charge unit
As a result the plasma layer was formed in the cross
section of the liner (Fig. 4). It served as a plasma anode
and a source of ions. In Fig. 4 the photos of the visible
spectrum of the voltage breakdown on the organic glass
surface at discharge start (a) and plasma layer formed
later (b) are shown.
а) б)
Fig. 4 Formation of plasma anode
The dot image (actually of red color) in Fig.4,a rep-
resents the light emitted by the light diode. It was in-
stalled for adjusting of the video camera sharpness. The
dark area in the glow of a plasma layer at the bottom of
Fig.4,b is the shadow image of the electrical probe. The
light emitting diode and Langmuir probe were placed
instead of one of the plasma guns. Density of formed
plasma on an axis of the drift chamber was equal
2×1013 сm-3.
5. MICROWAVE GENERATION
OF VIRCATOR AT PLASMA INJECTION
Additional confirmation of existence of the virtual
cathode in foregoing electrodynamic structure was the
microwave generation and radiation, power of which
did not practically depend on the value of external mag-
netic field induction. In Fig. 5 the oscillograms of pulses
of the detected microwave radiations of vircator are
shown. The pulse (1) corresponds to the generation at
the absence of external plasma. The maximum power of
radiation in this case was 0.2 MW. The power of mi-
crowave radiation was determined according to the
technique of paper [3]. The pulse (2) corresponds to
generation of microwave radiation at presence of plas-
ma formed by an external plasma source. The maximum
___________________________________________________________
PROBLEMS OF ATOMIC SIENCE AND TECHNOLOGY. 2004. № 2.
Series: Nuclear Physics Investigations (43), p.158-160.159
power of radiation of the plasma generator had value
5 MW. The duration of pulses of microwave radiation
was equal to duration of the REB current.
0,0 500,0n 1,0µ 1,5µ 2,0µ
-1,2
-1,0
-0,8
-0,6
-0,4
-0,2
0,0
0,2
1
2
V
ol
ta
ge
, V
Time, s
Fig.5. Vircator microwave radiation without (1)
and with (2) plasma gun
The observable low-frequency modulation of virca-
tor microwave radiation was probably caused by the
charge compensation of space charge of the virtual cath-
ode by plasma. It requires further research. The low
modulation frequency of microwave radiation had value
~40 MHz.
6. CONCLUSIONS
Thus, the microwave generator with supercritical
REB and external plasma anode was realized in the first
section of the collective ion accelerator. Comparison of
power radiation by the generator was made at the
absence and presence of the external plasma injection.
The presence of plasma in the electrodynamic structure
of the generator has resulted to increase of radiation
power more than one order of magnitude in comparison
with the vacuum case. The low frequency modulation of
microwave oscillations of the space charge was
probably formed by charge compensation of the virtual
cathode by plasma from the external source. Adding
confirmation of existence of these oscillations is the
presence of low-frequency modulation of the REB
collector current shown in paper [2].
This work was supported by STCU (project
No.1569).
REFERENCES
1. V. A. Balakirev, A. M. Gorban’, I. I. Magda et al
Collective acceleration of ions by modulated high-
current REB // Plasma Physics Reports. 1997, v.23,
No.4, p.323-327.
2. P.T. Chupikov, D.V. Medvedev, I.N. Onishchenko
et al. Experimental investigations of interaction of
supercritical electron beams with plasma // Prob-
lems of Atomic Science and Technology. Series:
Plasma Physics (7).2002, No.4, p.132.
3. S.B. Bludov, N.P. Gadetskiy, K.A. Kravtsov et al.
Generation of power microwave pulses ultra-short
duration and their influence on electron products //
Plasma physics. 1994, v.20, No.7-8, p.712. (in Rus-
sian)
СВЧ ГЕНЕРАЦИЯ СВЕРХКРИТИЧЕСКИМ РЭП ПРИ НАЛИЧИИ ПЛАЗМЫ
П.Т.Чупиков, И.Н.Онищенко, Ю.В.Прокопенко, С.С.Пушкарёв, А.М.Егоров
Проведены экспериментальные исследования генерации СВЧ излучения в системе со сверхкритическим
током релятивистского электронного пучка и внешним плазменным источником. Исследования показали,
что при наличии внешней плазмы мощность СВЧ излучения увеличивается по сравнению с вакуумной си-
стемой.
НВЧ ГЕНЕРАЦІЯ НАДКРИТИЧНИМ РЕП ПРИ НАЯВНОСТІ ПЛАЗМИ
П.Т.Чупіков, І.М.Оніщенко, Ю.В.Прокопенко, С.С.Пушкарьов, О.М.Єгоров
Проведені експериментальні дослідження генерації НВЧ випромінювання в системі з надкритичним
струмом релятивістського електронного пучка і зовнішнім плазмовим джерелом. Дослідження показали, що
при наявності зовнішньої плазми потужність НВЧ випромінювання збільшується в порівняні з вакуумною
системою.
160
NSC "Kharkov Institute of Physics and Technology"
Akademicheskaya St, 1, Kharkov – 61108, Ukraine
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