Microwave diagnostic system of the Uragan-2М torsatron
The construction of microwave sections together with results of loss calculation in the microwave lines for different frequencies are presented. The construction of microwave lead-ins is also described. The whole system has been well-tested on the Uragan-2M torsatron in conditions of SHF and RF clea...
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| Опубліковано в: : | Вопросы атомной науки и техники |
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| Дата: | 2008 |
| Автори: | , , , , , , , , |
| Формат: | Стаття |
| Мова: | Англійська |
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2008
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| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Цитувати: | Microwave diagnostic system of the Uragan-2М torsatron / D.A. Sitnikov, V.L. Berezhnyj, Y.V. Larin, S.M. Maznichenko, V.L. Ocheretenko, I.B. Pinos, А.V. Prokopenko, A.I. Skibenko, M.I. Tarasov // Вопросы атомной науки и техники. — 2008. — № 6. — С. 43-45. — Бібліогр.: 3 назв. — англ. |
Репозитарії
Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1859661675972526080 |
|---|---|
| author | Sitnikov, D.A. Berezhnyj, V.L. Larin, Y.V. Maznichenko, S.M. Ocheretenko, V.L. Pinos, I.B. Prokopenko, A.V. Skibenko, A.I. Tarasov, M.I. |
| author_facet | Sitnikov, D.A. Berezhnyj, V.L. Larin, Y.V. Maznichenko, S.M. Ocheretenko, V.L. Pinos, I.B. Prokopenko, A.V. Skibenko, A.I. Tarasov, M.I. |
| citation_txt | Microwave diagnostic system of the Uragan-2М torsatron / D.A. Sitnikov, V.L. Berezhnyj, Y.V. Larin, S.M. Maznichenko, V.L. Ocheretenko, I.B. Pinos, А.V. Prokopenko, A.I. Skibenko, M.I. Tarasov // Вопросы атомной науки и техники. — 2008. — № 6. — С. 43-45. — Бібліогр.: 3 назв. — англ. |
| collection | DSpace DC |
| container_title | Вопросы атомной науки и техники |
| description | The construction of microwave sections together with results of loss calculation in the microwave lines for different frequencies are presented. The construction of microwave lead-ins is also described. The whole system has been well-tested on the Uragan-2M torsatron in conditions of SHF and RF cleaning at a low magnetic field, and of pulse regime with a higher magnetic field up to 6 kOe. The results of testing are illustrated by temporal evolutions of plasma density and by digitalized signals from the detector.
Представлено конструкції НВЧ-трактів з розрахунком втрат в лініях на різних частотах і конструкції НВЧ- введень. НВЧ-комплекс, що описано, був випробуваний на торсатроні Ураган-2М в режимах НВЧ- і ВЧ- чищення при низькій напруженості магнітного поля, а також в імпульсному режимі з магнітним полем до 6 кЕ. Результати вимірювань ілюструються часовими залежностями густини і цифровими сигналами, отриманими з детектора.
Представлены конструкции СВЧ-трактов с расчетом потерь в линиях на различных частотах и конструкции СВЧ-вводов. Описанный СВЧ-комплекс испытан на торсатроне Ураган-2М в режимах СВЧ- и ВЧ- чистки при низкой напряженности магнитного поля, а также в импульсном режиме с магнитным полем до 6 кЭ. Результаты измерений иллюстрируются временными зависимостями плотности и цифровыми сигналами, полученными с детектора.
|
| first_indexed | 2025-11-30T10:06:06Z |
| format | Article |
| fulltext |
MICROWAVE DIAGNOSTIC SYSTEM
OF THE URAGAN-2M TORSATRON
D.A. Sitnikov, V.L. Berezhnyj, Y.V. Larin, S.M. Maznichenko, V.L. Ocheretenko,
I.B. Pinos, А.V. Prokopenko, A.I. Skibenko, M.I. Tarasov
IPP, National Science Center “Kharkov Institute of Physics and Technology”,
61108 Kharkov, Ukraine, e-mail: itarasov@ipp.kharkov.ua
The construction of microwave sections together with results of loss calculation in the microwave lines for different
frequencies are presented. The construction of microwave lead-ins is also described. The whole system has been well-
tested on the Uragan-2M torsatron in conditions of SHF and RF cleaning at a low magnetic field, and of pulse regime
with a higher magnetic field up to 6 kOe. The results of testing are illustrated by temporal evolutions of plasma density
and by digitalized signals from the detector.
PACS: 52.55.Hc
INTRODUCTION
The microwave interferometry and reflectometry
systems are created and tested to study time and space
characteristics of plasma density in the renewed U-2M
torsatron [1]. Cleaning of internal surfaces of the chamber
is made by low density SHF and RF discharges.
Therefore, the diagnostic system is developed for plasma
probing on frequencies f=10−140 GHz with
measurements of phase shifts πϕ )401.0( −=∆ . To
determine density profile at a low density, n~1012 cm-3,
application of reflectometry on frequencies f ≤ 10 GHz is
inexpedient. Therefore, it is necessary to carry out
interferometry along several chords.
In an l=2 torsatron the cross-section of the plasma
formation bounded by a magnetic surface looks as an
extended oval. Therefore, it is necessary to probe the
plasma along the major and minor axes.
Indication of phase shifts is made by phase beats and
raster methods.
The relationship between phase shift and density is
given by the formula
cr
l n
nlC
λ
πϕ −=∆ , where n - is
the electron density averaged over the length of wave
propagation. The factor lC is determined by density
distribution. At n < 0.2 ncr lC practically does not
depend on the form of this distribution ( lC ≈1) and the
phase shift of the wave is directly connected with the
average density of electrons.
The indication of phase shift by the raster method is
distinct by the displacement of characteristic points of
phase beats determined by the way of programming,
rather than by an instrumental way.
MEASUREMENT TECHNIQUES
To probe the plasma along the major and minor axes
of the oval, 5 waveguide channels in the poloidal cross-
section of the torus between the 9-th and 10-th toroidal
field coils and 2 waveguide channels between the 12-th
and 13-th coils are installed. The horn antennas allow to
make probing by the ordinary wave along and across the
the oval of plasma formation in two various cross-sections
(Fig.1a,b). The antennas II and III are intended for
interferometry and the antenna I is for reflectometry. The
antennas are designed as collapsible ones and are attached
to the waveguides inside the chamber (Fig.2). However,
in the regime of UHF cleaning the confining magnetic
configuration is not formed and only the antennas placed
outside the chamber are used.
Fig.1. Antenna arrays in the cross-sections (a) between
9-th and 10-th coils; (b) between 12-th and 13-th coils
Fig.2. Construction of microwave antenna insertion into
the chamber
The cross-sections of antenna I and antenna II
waveguides are 11×5.5 mm and 7.2×3.4mm, respectively.
That of antenna III is 7.2×3.4 mm and those of antennas
IV and V are 17×8.5 mm. The sizes of waveguide
channels provide probing within the 10-140 GHz range of
frequencies. The lengths of waveguide lines amount
15-18 m. Experimentally measured and calculated [3]
signal attenuations in the waveguides are tabulated in the
Table. The losses in connections and due to mode
PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. 2008. № 6. 43
Series: Plasma Physics (14), p. 43-45.
a b
conversion are not considered here.
Calculated and experimental values of signal attenuation
in the waveguide lines
Wavegu
ide size
17×8.5 mm,
λ = 1.2 cm
11×5.5 mm,
λ = 1.0 cm
7.2×3.4 mm,
λ = 0.83 cm
Type of
oscil.
Calc.
dB/m
Exper.
dB/m
Calc.
dB/m
Exper.
dB/m
Calc.
dB/m
Exper.
dB/m
ТE10
ТE20
ТE11
0.24
0.32
0.77
0.7
-
-
0.42
0.91
-
1.1
-
-
0.44
-
-
0.78
-
-
In Fig.1b the arrangement of waveguides in the
poloidal cross-section between the 12-th and 13-th
toroidal coils is shown. In this case, the antennas are
outside of the chamber and the probing is made through a
quartz glass. The waveguide cross-section is 11×5.5 mm.
In the Table the values of signal attenuation for
waveguides in this section are presented too. Such an
arrangement of waveguides allows to get rid of electrical
interference that can be picked up by waveguide elements
in the vacuum chamber. In this case, the probing is made
only along the minor radius of the plasma formation.
The applied sources of microwave radiation allow to
make probing within the range of 9-54 GHz, ensuring
measurements of the average density 5.0×1010− 1.2×
1010 cm-3 and the local density 6.0×1010− 3.6×1013 cm-3 (by
wave reflection).
The sources of microwave radiation and the receiving
equipment are enclosed into a steel box. From here, the
signals are transmitted to the control hall by fibre-optic
lines. To avoid electric interference, the receiving
equipment is electrically isolated from the waveguide
lines by insertion of dielectric waveguides between the
metal waveguides.
In this work, besides determination of phase shift by
interferogram extremums, a “zebra” type method is also used
with application of a program code for reproduction of
interference strips and their dynamics with density variation
[3]. The aim of program code is in finding maximum points
of the set array and to display them on the modulating saw.
The maximum is searched on a segment with N points. The
point with the maximal value should be in the middle of the
segment, otherwise, the segment is one point displaced and
the process is repeated (Fig.3).
EXPERIMENTAL RESULTS
Fragments of signals without and with the plasma
together with the modulating sawtooth-like pulse are
presented in Fig.3. The sawtooth period is 0.5 ms. The
signals are detected during RF cleaning (Fig.3). Also, the
detection could be possible in the pulse regime with a
higher magnetic field attaining 6 kОе. The phase beats are
displaced in time when the plasma occurs in the chamber.
Using the “zebra” type method of phase shift
indication, the interference strips are received with the use
of program code (Fig.4). Here, fragments of strips are
presented during occurrence of plasma in the chamber.
The distance between strips is π2 . Some points drop out
of the general picture during RF cleaning and in the pulse
regime, this being connected with density fluctuations
within the frequency modulation period. Using Fig.4, we
can construct density evolution in time (Fig.5).
Fig.3. Signals from detector in RF cleaning regime, λ
=0.8 cm
Fig.4. Strips in RF cleaning regimeλ =0.8cm
Fig.5. Time distribution of plasma density in the RF
cleaning regime
Experiments on density determination by the
interferometry method have been carried out. An example
of signal from the detector is presented in Fig.6. In the
case 1, the probing is made along the central chord (minor
axis) of plasma formation at the wavelength λ=8.2 mm
(L=30 cm), while in the case 2, along some outward-
shifted chord (major axis) at the wavelength λ=12 mm
(L=120 cm). A corresponding time evolution of density is
shown in Fig.7.
44
Fig.6. Interferometer signals with plasma probing along
the central (1) and outward-shifted (2) chords
Fig.7. Time behavior of plasma density, H=4.8 kOe
CONCLUSIONS
The results of first experiments on the renewed U-2M
torsatron obtained with the help of a microwave
diagnostic system show a possibility of density
measurements in a wide range n = 1010 − 5×1012 cm-3.
The raster method of phase shift indication based on
program determination of interference strip shifting with
plasma density variation has been developed and applied.
It is necessary to adapt the system for transmission
and indication of signals with frequencies up to 140 GHz
when the density increases up to the planned values 5×
1013 – 1014 cm-3.
It is intended to develop multi-chord probing up to 5
channels for the best spatial resolution.
In these experiments the maximum density up to n =
5×1012 cm-3 along the minor axis and approximately 30%
smaller one along the major axes are observed, this
difference might indicate that the maximum of density is
not crossed by the probing beam.
This work was partially supported by the Science and
Technology Center in Ukraine (STCU), Project #4216.
REFERENCES
1. V.K. Pashnev, V.I. Tereshin, E.D. Volkov et al.
Physical start of Uragan-2M torsatron // XXXIV
International conference on plasma physics and
controlled fusion. Book of abstracts. Zvenigorod,
February 12-16, 2007 (in Russian).
2. A.L. Fel’dshtejn, L.R. Yavich, V.P. Smirnov. The
directory on elements of waveguide techniques. М.:
”Energy”, 1967.
3. V.Е. Golant. Ultrahigh frequency methods of
investigation of plasma. М.: “Science”, 1968 (in Russian).
Article received 15.10.08.
СВЧ- ИЗМЕРИТЕЛЬНЫЙ КОМПЛЕКС НА ТОРСАТРОНЕ УРАГАН-2М
Д.А. Ситников, В.Л. Бережный, Ю.В. Ларин С.М. Мазниченко, В.Л. Очеретенко, И.Б. Пинос,
А.В. Прокопенко, А.И. Скибенко, М.И. Тарасов
Представлены конструкции СВЧ-трактов с расчетом потерь в линиях на различных частотах и конструкции
СВЧ-вводов. Описанный СВЧ-комплекс испытан на торсатроне Ураган-2М в режимах СВЧ- и ВЧ- чистки при
низкой напряженности магнитного поля, а также в импульсном режиме с магнитным полем до 6 кЭ. Результаты
измерений иллюстрируются временными зависимостями плотности и цифровыми сигналами, полученными с
детектора.
НІЧ- ВИМІРЮВАЛЬНИЙ КОМПЛЕКС НА ТОРСАТРОНІ УРАГАН-2М
Д.А. Ситников, В.Л. Бережний, Ю.В. Ларін, С.М. Мазніченко, В.Л. Очеретенко, І.Б. Пінос,
А.В. Прокопенко, А.І. Скибенко, М.І. Тарасов
Представлено конструкції НВЧ-трактів з розрахунком втрат в лініях на різних частотах і конструкції НВЧ-
введень. НВЧ-комплекс, що описано, був випробуваний на торсатроні Ураган-2М в режимах НВЧ- і ВЧ-
чищення при низькій напруженості магнітного поля, а також в імпульсному режимі з магнітним полем до 6 кЕ.
Результати вимірювань ілюструються часовими залежностями густини і цифровими сигналами, отриманими з
детектора.
45
|
| id | nasplib_isofts_kiev_ua-123456789-110800 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1562-6016 |
| language | English |
| last_indexed | 2025-11-30T10:06:06Z |
| publishDate | 2008 |
| publisher | Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| record_format | dspace |
| spelling | Sitnikov, D.A. Berezhnyj, V.L. Larin, Y.V. Maznichenko, S.M. Ocheretenko, V.L. Pinos, I.B. Prokopenko, A.V. Skibenko, A.I. Tarasov, M.I. 2017-01-06T13:06:56Z 2017-01-06T13:06:56Z 2008 Microwave diagnostic system of the Uragan-2М torsatron / D.A. Sitnikov, V.L. Berezhnyj, Y.V. Larin, S.M. Maznichenko, V.L. Ocheretenko, I.B. Pinos, А.V. Prokopenko, A.I. Skibenko, M.I. Tarasov // Вопросы атомной науки и техники. — 2008. — № 6. — С. 43-45. — Бібліогр.: 3 назв. — англ. 1562-6016 PACS: 52.55.Hc https://nasplib.isofts.kiev.ua/handle/123456789/110800 The construction of microwave sections together with results of loss calculation in the microwave lines for different frequencies are presented. The construction of microwave lead-ins is also described. The whole system has been well-tested on the Uragan-2M torsatron in conditions of SHF and RF cleaning at a low magnetic field, and of pulse regime with a higher magnetic field up to 6 kOe. The results of testing are illustrated by temporal evolutions of plasma density and by digitalized signals from the detector. Представлено конструкції НВЧ-трактів з розрахунком втрат в лініях на різних частотах і конструкції НВЧ- введень. НВЧ-комплекс, що описано, був випробуваний на торсатроні Ураган-2М в режимах НВЧ- і ВЧ- чищення при низькій напруженості магнітного поля, а також в імпульсному режимі з магнітним полем до 6 кЕ. Результати вимірювань ілюструються часовими залежностями густини і цифровими сигналами, отриманими з детектора. Представлены конструкции СВЧ-трактов с расчетом потерь в линиях на различных частотах и конструкции СВЧ-вводов. Описанный СВЧ-комплекс испытан на торсатроне Ураган-2М в режимах СВЧ- и ВЧ- чистки при низкой напряженности магнитного поля, а также в импульсном режиме с магнитным полем до 6 кЭ. Результаты измерений иллюстрируются временными зависимостями плотности и цифровыми сигналами, полученными с детектора. This work was partially supported by the Science and Technology Center in Ukraine (STCU), Project #4216. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Magnetic confinement Microwave diagnostic system of the Uragan-2М torsatron НІЧ- вимірювальний комплекс на торсатроні Ураган-2М СВЧ- измерительный комплекс на торсатроне Ураган-2М Article published earlier |
| spellingShingle | Microwave diagnostic system of the Uragan-2М torsatron Sitnikov, D.A. Berezhnyj, V.L. Larin, Y.V. Maznichenko, S.M. Ocheretenko, V.L. Pinos, I.B. Prokopenko, A.V. Skibenko, A.I. Tarasov, M.I. Magnetic confinement |
| title | Microwave diagnostic system of the Uragan-2М torsatron |
| title_alt | НІЧ- вимірювальний комплекс на торсатроні Ураган-2М СВЧ- измерительный комплекс на торсатроне Ураган-2М |
| title_full | Microwave diagnostic system of the Uragan-2М torsatron |
| title_fullStr | Microwave diagnostic system of the Uragan-2М torsatron |
| title_full_unstemmed | Microwave diagnostic system of the Uragan-2М torsatron |
| title_short | Microwave diagnostic system of the Uragan-2М torsatron |
| title_sort | microwave diagnostic system of the uragan-2м torsatron |
| topic | Magnetic confinement |
| topic_facet | Magnetic confinement |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/110800 |
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