Investigations of propagation, reflection and action on plasma of stochastic electromagnetic radiation
The broadband generator of stochastic electromagnetic oscillations in a decimetric band of waves lengths with output power ≈ 0,3 W is described. The epitaxial-planar VHF transistors of КТ911 type terminated by ring microstrips are used as an active elements. Electrical and amplitude-frequency charac...
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| Опубліковано в: : | Вопросы атомной науки и техники |
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| Дата: | 2002 |
| Автори: | , , , , , , , |
| Формат: | Стаття |
| Мова: | Англійська |
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2002
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| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Цитувати: | Investigations of propagation, reflection and action on plasma of stochastic electromagnetic radiation / A. Artamoshkin, A. Alisov, V. Antipov, I. Zagrebelny, N. Zemliansky, V. Karas`, V. Mirny, Ya. Fainberg // Вопросы атомной науки и техники. — 2002. — № 4. — С. 141-143. — Бібліогр.: 4 назв. — англ. |
Репозитарії
Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1860025430925377536 |
|---|---|
| author | Artamoshkin, A. Alisov, A. Antipov, V. Zagrebelny, I. Zemliansky, N. Karas`, V. Mirny, V. Fainberg, Ya. |
| author_facet | Artamoshkin, A. Alisov, A. Antipov, V. Zagrebelny, I. Zemliansky, N. Karas`, V. Mirny, V. Fainberg, Ya. |
| citation_txt | Investigations of propagation, reflection and action on plasma of stochastic electromagnetic radiation / A. Artamoshkin, A. Alisov, V. Antipov, I. Zagrebelny, N. Zemliansky, V. Karas`, V. Mirny, Ya. Fainberg // Вопросы атомной науки и техники. — 2002. — № 4. — С. 141-143. — Бібліогр.: 4 назв. — англ. |
| collection | DSpace DC |
| container_title | Вопросы атомной науки и техники |
| description | The broadband generator of stochastic electromagnetic oscillations in a decimetric band of waves lengths with output power ≈ 0,3 W is described. The epitaxial-planar VHF transistors of КТ911 type terminated by ring microstrips are used as an active elements. Electrical and amplitude-frequency characteristics of the generator are given. Spectral characteristics of oscillations were investigated by methods of correlation and phase-frequency analysis. We established, that oscillations have non-regular character with appreciable phases jumps.. The stochastic VHF oscillation with such characteristics will be used for investigation of its transmission, reflection and action on plasma.
|
| first_indexed | 2025-12-07T16:49:37Z |
| format | Article |
| fulltext |
INVESTIGATIONS OF PROPAGATION, REFLECTION AND ACTION
ON PLASMA OF STOCHASTIC ELECTROMAGNETIC RADIATION
A. Artamoshkin, A. Alisov, V. Antipov, I. Zagrebelny, N. Zemliansky,
V. Karas`, V. Mirny, Ya. Fainberg
National Scientific Center “Kharkov Institute of Physics and Technology”,
Kharkov 61108, Ukraine
The broadband generator of stochastic electromagnetic oscillations in a decimetric band of waves lengths with
output power ≈ 0,3 W is described. The epitaxial-planar VHF transistors of КТ911 type terminated by ring mi-
crostrips are used as an active elements. Electrical and amplitude-frequency characteristics of the generator are giv-
en. Spectral characteristics of oscillations were investigated by methods of correlation and phase-frequency analysis.
We established, that oscillations have non-regular character with appreciable phases jumps.. The stochastic VHF os-
cillation with such characteristics will be used for investigation of its transmission, reflection and action on plasma.
PACS: 52.35.-g
It is known [1] that considerable achievements in a
progress of plasma electronics are obtained lately, but
several of the important questions till now remains in-
sufficiently or at all not investigated. Among them as
more important question are theoretical and experimen-
tal researches of an interaction of stochastic electromag-
netic radiation with substance.
In stochastic electromagnetic fields, an acceleration
of charged particles, a heating of plasma [2] and lot of
other useful processes can effectively be realized. We
remind about fact that there is an exchange of energy
between VHF stochastic electromagnetic fields and
charged particles, although a pair encounters or syn-
chronism in movement of particles and propagation of
electromagnetic fields are absent. In this case, the fre-
quency of pair encounters will acted as a random phases
jumps of stochastic oscillations while the averaged over
a period energy acquired by a particle is proportional to
frequency of phase jumps.
Numerical simulation of transmission, reflection
both action of regular and stochastic electromagnetic ra-
diation upon particles of plasma at its incidence on a
vacuum-plasma boundary [3] has shown, that
monochromatic wave is being completely reflected (ex-
cept a front), while stochastic wave is being poorly re-
flected, what is connected mainly with a transmission of
pulses into plasma at jumping a wave phase. For a case,
when a broadband radiation has same spectral density of
energy and width of spectrum, as a stochastic radiation,
the transmission factor is on the order less in compari-
son with transmission factor in a case of a stochastic
wave.
Thus, it is possible to state, that the investigation of
interaction of stochastic VHF fields with substance will
give an essential addition to the theory of interaction
and considerably will expand an area of its possible ap-
plications.
For experimental investigations of processes features
of action of stochastic electromagnetic radiation upon
plasma the semiconducting generator of stochastic oscil-
lations was designed and made. Their spectral character-
istics were studied. The plan allowing to explore trans-
mission, reflection and action upon plasma of stochastic
radiation is offered.
For experimental investigations of processes features
of an interaction of stochastic oscillations with a sub-
stance it is necessary to have firstly generators of
stochastic electromagnetic oscillations, which should
agreed to the following main technical requirements:
– the band of generated frequencies should coincided
with frequency band of explored systems;
– necessary spectral density of power of stochastic os-
cillations should be determined;
– the law of distribution of instant values of an ampli-
tude of stochastic radiation should be preset;
– necessary regulation range of power level of stochas-
tic electromagnetic oscillations should be defined;
– output impedance of the generator should be matched
with an input wave impedance of coaxial or waveguide
transmission line;
– the value of instability of stochastic oscillations level
on an output of the generator should be preset at chang-
ing of environment conditions (temperature, damp etc.)
and of supply voltage.
To satisfy the first and second points of this require-
ments, as primary noise sources it is necessary to apply
such one, the band of generated frequencies which is not
less than given frequency band of electromagnetic oscil-
lations. The necessary power level of stochastic electro-
magnetic oscillations can be obtained with the help of
linear amplifier.
A varying of a power level of stochastic electromag-
netic oscillations is being realized by a usual method –
or on input of the amplifier, or directly by primary noise
source.
In consideration of above enumerated requirements
on designing such generators, we made the broadband
generator of stochastic electromagnetic oscillations,
which operates in a continuous mode. Schematic circuit
diagram of this generator is shown in Fig. 1.
Problems of Atomic Science and Technology. 2002. № 4. Series: Plasma Physics (7). P. 141-143 141
Fig. 1. Schematic circuit diagram of the generator:
W1 and W2 - ring microstrips; W3, С3 – components
for matching of generator output; VТ1, VТN - epitaxial-
planar VHF - transistors; VD1 - diode preventing fail-
ure of the generator, at accidental change of power
supply polarity; L1 – a filter choke; R1 – resistor pre-
setting a working point of transistors; С1, С2 – con-
densers, which support necessary back-couplings.
The generator is assembled according to three-dot
schema with a capacitive feedback [4] on epitaxial-pla-
nar VHF transistors of КТ911 type terminated by ring
microstrips, and operates in free-running mode. Ring
microstrips are the strips of definite sizes, which are
etched on bilateral foiling fiberglass. The geometrical
sizes of microstrips choose by such, that they were L-C
distributed-parameters lines for the given frequencies
band, and them wave impedance was 50 ÷ 75 Ω. We
managed to expand generated oscillations band and to
reduce nonuniformity of amplitude-frequency response
by an inserting into the circuitry of additional capacitive
negative feedbacks and by a finding of optimum places
of their connection on microstrips.
The generator operates in voltage range from 6 up to
12 V and consumed current from 0.3 up to 0.8 A ac-
cordingly. The average VHF power of the generator
measured by digital wattmeter М3-54 is 0.3 W. The
generator has overall dimensions (without the power
supply) 140x140x50 mm, and the weight is not exceed
200 g.
For experimental researches of processes features of
action on plasma of stochastic electromagnetic radiation
it is necessary, first of all, to study spectral characteris-
tics of this radiation. With this purpose we used a
method of an obtaining of oscillations realizations and
postprocessing them on computer. Autocorrelation func-
tions, correlation times, power density spectrum, tempo-
ral fluctuations of oscillation phase were determined by
methods of correlation and phase-frequency analysis.
As a result of these researches we established, that
the semiconductor broadband generator of stochastic os-
cillations operating in continuous mode generates oscil-
lations in the frequency band from 20 MHz up to
870 MHz. In Fig. 2 the generator amplitude-frequency
characteristic snapshot made from the shield of spec-
trum analyzer S4-60 is shown.
Fig. 2. An amplitude-frequency characteristic of the
generator.
Also the realizations snapshots of generated stochas-
tic oscillations made by the cinecamera from the shield
of high-frequency oscillograph S7-19 were investigated.
From the oscillations realization (the sweep length
30 ns) shown in Fig. 3 one can see that they have non-
regular character with appreciable phases jumps.
Fig. 3. The oscillogram of high-frequency signal.
The temporary autocorrelation function of oscilla-
tions in per-unit is shown in Fig. 4.
0 4 8
- 0 . 4
0 . 0
0 . 4
0 . 8
1 . 2
R ( t )
t, ns
Fig. 4. Autocorrelation function of oscillations.
The times of a correlation of high-frequency oscilla-
tions are determined and in our case they are corrτ = 2 ÷
2.5 ns. As time of a correlation is related to spectrum
width of generated oscillations by a ratio fcorr ∆⋅τ
≈ 1, one can see that wide frequency spectrum corre-
sponds to small times of a correlation. In our case f∆ ≈
400 ÷ 500 MHz that accords with spectrum half-breadth
on the curve of spectral density of oscillations power in
per-unit as a function of frequency shown in Fig. 5.
142
0 1 2
0 . 0
0 . 2
0 . 4
0 . 6
S ( f )
f, GHz
Fig. 5. A spectral power density of oscillations.
It is known that the smaller correlation time and the
wider frequency spectrum of oscillations, the larger de-
gree of stochasticity. Therefore in our case the generat-
ed VHF oscillations are stochastic. On it points out also
existence of phase jumps on the curve of change of total
phase ϕ (in radians) of oscillation as a function of
time, where a nonstationarity of behaviour of a frequen-
cy-temporary relationship is clearly observed also. The
frequency of jumps of an oscillation phase for our case
is jmpf ≈ 600 MHz that one can see in Fig. 6.
0 1 0 2 0 3 0
0
1 0
2 0
3 0
4 0
t, ns
ϕ , рад
Fig. 6. The oscillations phase as a function of time.
The stochastic VHF oscillation with such character-
istics will be used for investigation of its transmission,
reflection and action on plasma.
Research of action features of these oscillations
upon plasma in comparison with regular ones will be
carried out on installation, in which the plasma is creat-
ed by magnetron operating in continuous mode on
wavelength ≈ 12 cm in cylindrical cavity 450 mm in di-
ameter and 500 mm in length.
REFERENCES
[1] Ya.B. Fainberg. Plasma electronics and plasma
methods of acceleration of charged particles.// Plas-
ma physics, 2000, v. 26. p. 362.
[2] Ya.B. Fainberg, F.G. Bass, V.D. Shapiro. The quasi-
linear theory of weak turbulent plasma in view of a
correlation of electric fields. GEТF, 1965, v. 49,
No.1 (7), p.329-334.
[3] V.I. Karas', et al. Theoretical researches and numeri-
cal simulation of transmission, reflection both action
of regular and stochastic electromagnetic radiation
on particles of plasma at its incidence on boundary
vacuum-plasma. International Conference, Zvenig-
orod, 2001.
[4] B.S. Gershunsky. Calculation of the main electron
and semi-conductor circuits. Pab. Kiev. Univer.,
1968, p.196.
143
|
| id | nasplib_isofts_kiev_ua-123456789-80304 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1562-6016 |
| language | English |
| last_indexed | 2025-12-07T16:49:37Z |
| publishDate | 2002 |
| publisher | Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| record_format | dspace |
| spelling | Artamoshkin, A. Alisov, A. Antipov, V. Zagrebelny, I. Zemliansky, N. Karas`, V. Mirny, V. Fainberg, Ya. 2015-04-14T17:25:24Z 2015-04-14T17:25:24Z 2002 Investigations of propagation, reflection and action on plasma of stochastic electromagnetic radiation / A. Artamoshkin, A. Alisov, V. Antipov, I. Zagrebelny, N. Zemliansky, V. Karas`, V. Mirny, Ya. Fainberg // Вопросы атомной науки и техники. — 2002. — № 4. — С. 141-143. — Бібліогр.: 4 назв. — англ. 1562-6016 PACS: 52.35.-g https://nasplib.isofts.kiev.ua/handle/123456789/80304 The broadband generator of stochastic electromagnetic oscillations in a decimetric band of waves lengths with output power ≈ 0,3 W is described. The epitaxial-planar VHF transistors of КТ911 type terminated by ring microstrips are used as an active elements. Electrical and amplitude-frequency characteristics of the generator are given. Spectral characteristics of oscillations were investigated by methods of correlation and phase-frequency analysis. We established, that oscillations have non-regular character with appreciable phases jumps.. The stochastic VHF oscillation with such characteristics will be used for investigation of its transmission, reflection and action on plasma. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Plasma electronics Investigations of propagation, reflection and action on plasma of stochastic electromagnetic radiation Article published earlier |
| spellingShingle | Investigations of propagation, reflection and action on plasma of stochastic electromagnetic radiation Artamoshkin, A. Alisov, A. Antipov, V. Zagrebelny, I. Zemliansky, N. Karas`, V. Mirny, V. Fainberg, Ya. Plasma electronics |
| title | Investigations of propagation, reflection and action on plasma of stochastic electromagnetic radiation |
| title_full | Investigations of propagation, reflection and action on plasma of stochastic electromagnetic radiation |
| title_fullStr | Investigations of propagation, reflection and action on plasma of stochastic electromagnetic radiation |
| title_full_unstemmed | Investigations of propagation, reflection and action on plasma of stochastic electromagnetic radiation |
| title_short | Investigations of propagation, reflection and action on plasma of stochastic electromagnetic radiation |
| title_sort | investigations of propagation, reflection and action on plasma of stochastic electromagnetic radiation |
| topic | Plasma electronics |
| topic_facet | Plasma electronics |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/80304 |
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