High-frequency generation during the electron flow deceleration and reflection by the electrostatic potential
In this work we present the results of experimental study of generation of the RF-oscillations in a classic flat triode configuration for both presence and absence of the reflected particles flow. The amplitude and frequency characteristics are studied. The behavior of main characteristic parameters...
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| Опубліковано в: : | Вопросы атомной науки и техники |
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| Дата: | 2013 |
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| Мова: | Англійська |
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2013
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| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Цитувати: | High-frequency generation during the electron flow deceleration and reflection by the electrostatic potential / M.I. Tarasov, A.V. Pashchenko, D.A. Sitnikov, S.S. Romanov, I.M. Shapoval // Вопросы атомной науки и техники. — 2013. — № 1. — С. 99-101. — Бібліогр.: 5 назв. — англ. |
Репозитарії
Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1859768731181252608 |
|---|---|
| author | Tarasov, M.I. Pashchenko, A.V. Sitnikov, D.A. Romanov, S.S. Shapoval, I.M. |
| author_facet | Tarasov, M.I. Pashchenko, A.V. Sitnikov, D.A. Romanov, S.S. Shapoval, I.M. |
| citation_txt | High-frequency generation during the electron flow deceleration and reflection by the electrostatic potential / M.I. Tarasov, A.V. Pashchenko, D.A. Sitnikov, S.S. Romanov, I.M. Shapoval // Вопросы атомной науки и техники. — 2013. — № 1. — С. 99-101. — Бібліогр.: 5 назв. — англ. |
| collection | DSpace DC |
| container_title | Вопросы атомной науки и техники |
| description | In this work we present the results of experimental study of generation of the RF-oscillations in a classic flat triode configuration for both presence and absence of the reflected particles flow. The amplitude and frequency characteristics are studied. The behavior of main characteristic parameters for both cases was analyzed and compared.
Представлены результаты экспериментального исследования ВЧ-генерации в триоде в режимах с наличием и отсутствием отраженного потока. Исследуются амплитудные и частотные параметры. Проводится сравнительный анализ.
Представлено результати експериментального дослідження ВЧ-генерації в тріоді в режимах з відсутнім та наявним потоком відбитих електронів. Досліджуються амплітудні та частотні характеристики. Проведено порівняльний аналіз.
|
| first_indexed | 2025-12-02T06:15:01Z |
| format | Article |
| fulltext |
ISSN 1562-6016. ВАНТ. 2013. №1(83) 99
HIGH-FREQUENCY GENERATION DURING THE ELECTRON FLOW
DECELERATION AND REFLECTION BY THE ELECTROSTATIC
POTENTIAL
M.I. Tarasov, A.V. Pashchenko, D.A. Sitnikov, S.S. Romanov, I.M. Shapoval
Institute of Plasma Physics National Science Center
“Kharkov Institute of Physics and Technology”, Kharkov, Ukraine
E-mail: itarasov@ipp.kharkov.ua
In this work we present the results of experimental study of generation of the RF-oscillations in a classic flat
triode configuration for both presence and absence of the reflected particles flow. The amplitude and frequency
characteristics are studied. The behavior of main characteristic parameters for both cases was analyzed and
compared.
PACS: 03.65.Pm, 03.65.Ge, 61.80.Mk
INTRODUCTION
In this work we study the main features of RF-power
generation in the flat triode system in which electron
flow is accelerated in the space between the indirectly
heated cathode and grid electrode and is decelerated
when passing towards the anode.
The study of RF – radiation was carried out in two
different modes with negative and positive anode
potential respectively. The first one represents a well-
known Barkhausen-Kurtz generation while the positive
anode potential mode was not previously studied in a
proper way. It was experimentally observed by
V.I. Kalinin [1] but was never considered as a separate
mode.
EXPERIMENTAL SETUP
The electron beam instability was found and
investigated experimentally in the devices, which
simulated the conditions of the instability. The electron
flow was investigated in a planar triode electrode
geometry. The experimental setup is presented in Fig.1.
Fig. 1. The schematic experimental setup (a) and the
distributions of longitudinal potential (b, c)
The electron flow produced by indirectly heated
cathode propagated towards anode and grid. The linear
dimensions of the electrodes (grid, anode) substantially
exceeded the spacing between electrodes (l = 0.35 cm).
The cathode-grid and grid-anode separation distances
are in the ratio of 1:5. In the experiments, we measured
the anode and grid voltages (U2 and U1), the emission
current density, and the oscillations spectrum. The
amplitude of oscillations was also measured, and the
increments were estimated. The vacuum chamber, in
which the experiments were performed, was pumped
down to a residual pressure of 2·10-6 Torr. In the second
case, the residual pressure was estimated to be about 10-
7 Torr. In both cases, the cathode was grounded.
EXPERIMENTAL RESULTS
Generation of high-frequency oscillations was
observed when the potential of the metal grid was
significantly higher than the anode potential. That
means that the phenomenon takes place when the flow
of electrons is decelerated. In the case of negative anode
potential, most of the flow particles were reflected. Thus
a “reversed flow” occurs. Otherwise, if the anode
potential is positive, the “reversed flow” is not clearly
detected.
It was shown that increasing U1 (the grid voltage)
leads to the anode current growth. At the same time the
increase of negative anode potential cause the flow
current damping (Fig. 2), what may be considered as
particles reflection. Thus, the experiment carried out at
the negative anode potential deals with both forward
and reversed flows.
Fig. 2. The case of negative anode potential: volt-
ampere characteristics
The oscillations frequency exhibited a strong growth
(from 90 to 180 MHz) during the grid voltage increase
(U1 = 30…300 V), Fig. 3,a,b. Increasing the reflecting
anode potential (U2) at the relatively high values of grid
voltage (U1 > 150 V) results in noticeable frequency
100 ISSN 1562-6016. ВАНТ. 2013. №1(83)
growth. The frequency spectrum was not clearly linear.
For low anode potentials U2 = - (9…21) V the
frequency band width is maximal for small accelerating
grid voltages.
Fig. 3. The case of negative anode potential: RF – generation averaged frequency value (a,b) and band width
(c,d) for different anode and grid potentials
Fig. 4. The case of positive anode potential: generation
parameters (a) and volt-ampere characteristics (b)
When U2 = - (24…30) V the maximum shifts to
higher values of U1, Fig.3,c,d.
Fig. 5. The case of positive anode potential: volt-
ampere characteristics (a) and generation parameters
(b) increased system size (l = 3 cm)
ISSN 1562-6016. ВАНТ. 2013. №1(83) 101
In case of the positive anode potential there is no
noticeable “reversed flow”. The frequency of
oscillations similarly grows during the grid voltage
increase but the generation range is much narrower and
the frequency dependences are more volatile.
The frequency values are also slightly lower than in
the negative anode case.
For example, if U2 changes from 30 to 300 V the
oscillations frequency grows from 45 to 160 MHz
(Fig. 4).
The experiments provided in similar system with
significantly bigger longitudinal size show the
frequency decrease. At the same time the generation
spectrum was enriched by a number of additional
harmonics. For the first harmonic the frequency varied
between 25 and 60 MHz. For higher harmonics the
frequency exceeded 400 MHz.
The results mentioned above were obtained at U2 = 9 V.
This regime corresponded to the flow deceleration
without a noticeable reverse flow formation (Fig. 5).
CONCLUSIONS
A comparative analysis of two generation modes
demonstrates sufficient difference in the flow dynamics.
Application of negative electrostatic potential to the
anode of the system creates a ‘reversed flow’ which
passes through the metal grid electrode towards the
cathode. Most particles then become reflected by the
cathode potential and move towards the grid electrode.
Finally the flow particles oscillate around the grid
electrode. This process causes the RF-oscillations in the
anode current.
The value of anode potential in this mode affected
strongly the RF – generation dynamics.
If the anode potential is positive the ‘reversed flow’
is usually not detected. The RF – oscillations are
therefore localized in the space between the metal grid
and anode. The mechanism of such generation is based
on the process of energy exchange between the flow
particles and the oscilations caused by the system own
capacity ant inductivity.
The frequency of oscillations in this mode is less
sensitive to the value of anode potential. The frequency
magnitudes are slightly smaller than those for the flow
reflection modes.
The increase of the system size leads to reduction of
RF-oscillation frequency. At the same time it is much
easier to observe a higher harmonics of the main
generation frequency in such higher-scale devices.
REFERENCES
1. V.I. Kalinin // JTP. 1933, v. 3, issue 2-3, p. 332.
2. V.F. Kovalenko // JTP. 1938, v. 8, issue 5, p. 425.
3. V.A. Buts // JTP. 1972, v. XLII, issue 4, p. 709.
4. D.N. Klochkov, M.Yu. Pekar, A.A. Rukhadze //
Plasma Phys. Rep. 1999, v. 25, № 6, p. 552-557.
5. A.V. Pashchenko, V.M. Zalkind, Yu.V. Lonin, et al.
// JTP Lett. 2008, v. 34, issue 24, p. 83-88.
Article received 05.11.12
ВЧ-ГЕНЕРАЦИЯ ПРИ ТОРМОЖЕНИИ И ОТРАЖЕНИИ ЭЛЕКТРОННОГО ПОТОКА
ЭЛЕКТРОСТАТИЧЕСКИМ ПОТЕНЦИАЛОМ
М.И. Тарасов, А.В. Пащенко, Д.А. Ситников, С.С. Романов, И.Н. Шаповал
Представлены результаты экспериментального исследования ВЧ-генерации в триоде в режимах с
наличием и отсутствием отраженного потока. Исследуются амплитудные и частотные параметры.
Проводится сравнительный анализ.
ВЧ-ГЕНЕРАЦІЯ ПРИ ГАЛЬМУВАННІ ТА ВІДБИТТІ ЕЛЕКТРОННОГО ПОТОКУ
ЕЛЕКТРОСТАТИЧНИМ ПОТЕНЦІАЛОМ
М.І. Тарасов, А.В. Пащенко, Д.А. Сітников, С.С. Романов, І.М. Шаповал
Представлено результати експериментального дослідження ВЧ-генерації в тріоді в режимах з відсутнім
та наявним потоком відбитих електронів. Досліджуються амплітудні та частотні характеристики. Проведено
порівняльний аналіз.
|
| id | nasplib_isofts_kiev_ua-123456789-109263 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1562-6016 |
| language | English |
| last_indexed | 2025-12-02T06:15:01Z |
| publishDate | 2013 |
| publisher | Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| record_format | dspace |
| spelling | Tarasov, M.I. Pashchenko, A.V. Sitnikov, D.A. Romanov, S.S. Shapoval, I.M. 2016-11-22T10:47:56Z 2016-11-22T10:47:56Z 2013 2013 High-frequency generation during the electron flow deceleration and reflection by the electrostatic potential / M.I. Tarasov, A.V. Pashchenko, D.A. Sitnikov, S.S. Romanov, I.M. Shapoval // Вопросы атомной науки и техники. — 2013. — № 1. — С. 99-101. — Бібліогр.: 5 назв. — англ. 1562-6016 PACS: 03.65.Pm, 03.65.Ge, 61.80.Mk https://nasplib.isofts.kiev.ua/handle/123456789/109263 In this work we present the results of experimental study of generation of the RF-oscillations in a classic flat triode configuration for both presence and absence of the reflected particles flow. The amplitude and frequency characteristics are studied. The behavior of main characteristic parameters for both cases was analyzed and compared. Представлены результаты экспериментального исследования ВЧ-генерации в триоде в режимах с наличием и отсутствием отраженного потока. Исследуются амплитудные и частотные параметры. Проводится сравнительный анализ. Представлено результати експериментального дослідження ВЧ-генерації в тріоді в режимах з відсутнім та наявним потоком відбитих електронів. Досліджуються амплітудні та частотні характеристики. Проведено порівняльний аналіз. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Фундаментальная физика плазмы High-frequency generation during the electron flow deceleration and reflection by the electrostatic potential ВЧ-генерация при торможении и отражении электронного потока электростатическим потенциалом ВЧ-генерація при гальмуванні та відбитті електронного потоку електростатичним потенціалом Article published earlier |
| spellingShingle | High-frequency generation during the electron flow deceleration and reflection by the electrostatic potential Tarasov, M.I. Pashchenko, A.V. Sitnikov, D.A. Romanov, S.S. Shapoval, I.M. Фундаментальная физика плазмы |
| title | High-frequency generation during the electron flow deceleration and reflection by the electrostatic potential |
| title_alt | ВЧ-генерация при торможении и отражении электронного потока электростатическим потенциалом ВЧ-генерація при гальмуванні та відбитті електронного потоку електростатичним потенціалом |
| title_full | High-frequency generation during the electron flow deceleration and reflection by the electrostatic potential |
| title_fullStr | High-frequency generation during the electron flow deceleration and reflection by the electrostatic potential |
| title_full_unstemmed | High-frequency generation during the electron flow deceleration and reflection by the electrostatic potential |
| title_short | High-frequency generation during the electron flow deceleration and reflection by the electrostatic potential |
| title_sort | high-frequency generation during the electron flow deceleration and reflection by the electrostatic potential |
| topic | Фундаментальная физика плазмы |
| topic_facet | Фундаментальная физика плазмы |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/109263 |
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