Experiments with the tiny nanosecond output device on the S-300 high-current generator
On the S-300 pulsed power generator (4.5 MA, 70 ns, 0.15 Ohm), within the frames of ICF program based on fast high-current Z-pinches, experiments are being carried out studying promising schemes of output units. In particular, a device similar to the plasma flow switch is being investigated aimed at...
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| Опубліковано в: : | Вопросы атомной науки и техники |
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| Дата: | 2003 |
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2003
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| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Цитувати: | Experiments with the tiny nanosecond output device on the S-300 high-current generator / A.S. Kingsep, Yu.L. Bakshaev, A.V. Bartov, P.I. Blinov, A.S. Chernenko, R.V. Chikin, K.V. Chukbar, S.A. Danko, L.G. Dubas, Yu.G. Kalinin, I.V. Kovalenko, A.I. Lobanov, V.I. Mizhiritsky, V.A. Shchagin, V.P. Smirnov // Вопросы атомной науки и техники. — 2003. — № 4. — С. 26-28. — Бібліогр.: 4 назв. — англ. |
Репозитарії
Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1859743153181949952 |
|---|---|
| author | Kingsep, A.S. Bakshaev, Yu.L. Bartov, A.V. Blinov, P.I. Chernenko, A.S. Chikin, R.V. Chukbar, K.V. Danko, S.A. Dubas, L.G. Kalinin, Yu.G. Kovalenko, I.V. Lobanov, A.I. Mizhiritsky, V.I. Shchagin, V.A. Smirnov, V.P. |
| author_facet | Kingsep, A.S. Bakshaev, Yu.L. Bartov, A.V. Blinov, P.I. Chernenko, A.S. Chikin, R.V. Chukbar, K.V. Danko, S.A. Dubas, L.G. Kalinin, Yu.G. Kovalenko, I.V. Lobanov, A.I. Mizhiritsky, V.I. Shchagin, V.A. Smirnov, V.P. |
| citation_txt | Experiments with the tiny nanosecond output device on the S-300 high-current generator / A.S. Kingsep, Yu.L. Bakshaev, A.V. Bartov, P.I. Blinov, A.S. Chernenko, R.V. Chikin, K.V. Chukbar, S.A. Danko, L.G. Dubas, Yu.G. Kalinin, I.V. Kovalenko, A.I. Lobanov, V.I. Mizhiritsky, V.A. Shchagin, V.P. Smirnov // Вопросы атомной науки и техники. — 2003. — № 4. — С. 26-28. — Бібліогр.: 4 назв. — англ. |
| collection | DSpace DC |
| container_title | Вопросы атомной науки и техники |
| description | On the S-300 pulsed power generator (4.5 MA, 70 ns, 0.15 Ohm), within the frames of ICF program based on fast high-current Z-pinches, experiments are being carried out studying promising schemes of output units. In particular, a device similar to the plasma flow switch is being investigated aimed at sharpening the pulse. In the experiments with such a device, by means of variation the geometry of the inner electrode of a co-axial, as well as the acceleration of a cascade of plasma “washers”, the switching of the current up to 750 kA has been obtained, with the rise time ~ 5…7 ns and subsequent decrease being in accordance with that of the net current (~ 100 ns). Thereby the opportunity of switching of much more amount of energy onto the load has been demonstrated compared to our preliminary experiments (2.5 MA/2.5 ns). Soft X-ray radiation from the cavity was recorded by means of vacuum diodes with a nickel cathode and especially selected filters. The radiative temperature of the cavity walls estimated from the ratio of diode signals was close to 50 eV.
|
| first_indexed | 2025-12-01T19:39:43Z |
| format | Article |
| fulltext |
UDC 533.9
EXPERIMENTS WITH THE TINY NANOSECOND OUTPUT DEVICE
ON THE S-300 HIGH-CURRENT GENERATOR
A.S. Kingsep1, Yu.L. Bakshaev1, A.V. Bartov1, P.I. Blinov1, A.S. Chernenko1,
R.V. Chikin1, K.V. Chukbar1, S.A. Danko1, L.G. Dubas1, Yu.G. Kalinin1, I.V. Kovalenko2,
A.I. Lobanov2, V.I. Mizhiritsky1, V.A. Shchagin1, V.P. Smirnov1
1RRC “Kurchatov Institute”, 1 Kurchatov Sq., Moscow, 123182, Russia;
2Moscow Institute for Physics and Technology, Dolgoprudnyi, 141700, Russia
On the S-300 pulsed power generator (4.5 MA, 70 ns, 0.15 Ohm), within the frames of ICF program based on
fast high-current Z-pinches, experiments are being carried out studying promising schemes of output units. In partic-
ular, a device similar to the plasma flow switch is being investigated aimed at sharpening the pulse. In the experi-
ments with such a device, by means of variation the geometry of the inner electrode of a co-axial, as well as the ac-
celeration of a cascade of plasma “washers”, the switching of the current up to 750 kA has been obtained, with the
rise time ~ 5…7 ns and subsequent decrease being in accordance with that of the net current (~ 100 ns). Thereby the
opportunity of switching of much more amount of energy onto the load has been demonstrated compared to our pre-
liminary experiments (2.5 MA/2.5 ns). Soft X-ray radiation from the cavity was recorded by means of vacuum
diodes with a nickel cathode and especially selected filters. The radiative temperature of the cavity walls estimated
from the ratio of diode signals was close to 50 eV.
1. INTRODUCTION
Fast compression of high-current Z-pinches is under
consideration as a possible approach to electric energy
conversion into X-ray pulse at the energy scale of
dozens of megajoules aimed at the inertial confinement
fusion (ICF) as well as experimental study of the ex-
treme state of matter. Nowadays, the typical load of the
pulsed power machine of megaampere range is based on
the array of wires of the micrometer thickness. Scientif-
ic cooperation including TRINITI, Kurchatov institute,
Efremov institute, and VNIITF develops the “Baikal”
project [1,2] in which an inductive storage has to be
used which in the case of successive transformation pro-
cedure could produce an electric pulse with parameters
adequate for ICF. Unfortunately, one of the shortcom-
ings of such schemes is the X-ray radiation into the sol-
id angle equal to 4π that results in the reduction of ener-
gy density and, consequently, the equivalent tempera-
ture since the radiation fills the whole volume of the
output unit. As a result, the experiments with a
Hohlraum are available now only on the level of
“Z”-machine at “Sandia” laboratories [3]. The goal of
ICF experiments in Kurchatov institute is to study some
new kinds of tiny output units those could provide the
Hohlraum experiments at the current generation of high-
current machines.
2. NANOSECOND PLASMA FLOW SWITCH
We investigated especial output devices similar to
the plasma flow switch but operating in the nanosecond
range of pulse duration. The plasma bridge between the
inner and outer cylinders was accelerated along the axis
by means of the current pulse of generator. The scheme
of our output device has been shown in Fig. 1. Acceler-
ated plasma bridge moves along the inner coaxial cylin-
der. When it is flying through the break of the inner
cylinder, the circuit becomes to be broken, as a result,
the magnetic flux enters the central cavity where the
load is situated. The plasma bridge was created by
means of the current-driven explosion of a thin foil in
very beginning of the current pulse. Diameters of inner
and outer cylinders were equal to 4 and 10 mm, respec-
tively. The break of inner cylinder was varied between 1
to 2.6 mm. The diameter and length of central cavity
were equal to 3.6 mm and 10 mm, respectively. The
maximal current value was close to 2.5…3.0 MA. We
used the accelerated foils produced of different materi-
als, to wit, metallic foils as thick as 5–10 µm, mylar
films of 2…5 µm, nitro-cellulose films with thickness
<1 µm, and aluminum-coated mylar films of 1.2…1.5 µ
m. The homogeneity of breakdown of foils and the ve-
locity of their sliding along the inner electrode were
recorded by means of both frame and streak ICT pho-
tographs in visible range. The maximal velocity of slid-
ing recorded was up to 108 cm/s. The better results of
the
Fig.1. The sketch of output device
current series were achieved by using plastic “washers”
of 1.2…1.5 µm thickness coated by very thin aluminum
layer. As loads in the first experiments we used metallic
wires or tubes with the diameter of 0.5…2 mm. The mo-
ment of current switching on the load and the current
amplitude were determined by means of the shunt mea-
surements. The shunt (see Fig.1) was made of steel foil
as thin as it was necessary to provide the time resolution
∆τ<2 ns. As our simulations show, heating of this shunt-
ing foil does not distort essentially the signal up to the
moment of maximal current amplitude. The current rise
time on the load varied from 2.5 ns up to 10 ns.
Fig. 2. Traces of the current on a load (top) and total current (bottom)
The current amplitude was up to 2.5 MA. Heretofore,
such a switching rate (1015 A/s) has been achieved only
in our experiments. In Fig. 2, on can see the oscillo-
scope traces of both input current and current switched
onto the metallic tube of 1.5 mm in diameter that served
as a load. Nowadays, we operate with new loads, name-
ly, wire arrays of the small diameter (~2 mm) set up in
the cavity of the inner electrode.
3. SIMULATIONS
We have carried out a series of simulations of the
dynamics of plasma “washer” on the base of single-flu-
id, two-temperature MHD code with the effects of radi-
ation transfer and Electron Magnetohydrodynamics
(EMHD, see [4]) included. At first sight, EMHD effects
should be immaterial in this problem since the typical
space scale of both plasma washer and Z-pinch are at
least one order of magnitude more than / pic ω . How-
ever, our simulations result in the important role of
EMHD. Not only quantitative results, even scenarios in
pure MHD and Hall MHD (EMHD) turn out to be dif-
ferent. We believe, this effect is conditioned by the gen-
eration, in the process of the plasma bridge acceleration,
space scales much less than the basic scale of the prob-
lem, especially in the regions close to the electrodes.
Simulations show an essential dependence of the accel-
eration and consequent switching upon the initial plas-
ma temperature, to wit, the “warm” plasma bridge
(~8…10 eV) is preferable from the standpoint of its sta-
bility and efficiency of switching.
4. CASCADE SYSTEM OF FOILS
To form less diffusive outer boundary of our plasma
bridge, we have used the system of double “washers”, to
wit, two mylar foils, each one being of 1.5 µm thick-
ness, with 1…2 mm gap between them. Besides, to pre-
vent from breaking the plasma bridge near the inner
electrode resulting in the formation of parasitic plasma
opening switch, we used a conical inner electrode with a
diameter growing in the direction of the plasma bridge
motion.
Figure 3. Oscilloscopic traces corresponding to the
cascade scheme experiment
An example of oscilloscopic traces is shown in Fig.3.
Here the trace 1 presents the net current I obtained by
the analogous integration of the signals from the diag-
nostic loops, 2 – the same current I integrated numeri-
cally, 3 – the signal dI /dt, trace 4 – the value of IL,
where IL is the current on the load, trace 5 – the soft X-
ray signal recorded just from the spatial region of
switching (see the gap in Fig.1). The first pike on this
curve corresponds to the impact of two foils and the sec-
ond one – to the moment of switching. As one can see,
the switched current value in this shot was ~750 kA/5
ns, and the time scale of subsequent current decrease
was the same as that of the net current, unlike the ex-
treme regime shown in Fig.2. As a load, an array of 8 to
16 tungsten wires was used with the diameter of 5 to 6 µ
m collected in the array with the radius of 1 mm.
Except of registration of the electric signals, we
recorded the soft X-ray radiation (SXR) of both com-
pressed Z-pinch and the solid walls of the Hohlraum, in
the range of hν ≥ 50 eV. These measurements were
carried out by means of the vacuum X-ray diodes
(XRD) with the Ni photo-cathodes, supplied by mylar
filters with the mass thickness = 0, 0.34 mg/cm2, and
0.67 mg/cm2. SXR pulse recorded from the load served
as the witness of switching. SXR signal of the pinch
recorded from its edge, if supposed to be nearly Planck-
ian, may be used to obtain the following estimates:
T ≅ 140 eV, 20hE ν ≈ J, and the efficient radiating
cross-section area S ≅ 2⋅10–5 cm2. To some extent,
these results remain indefinite since we cannot resolve
the hot spots of Z-pinch. We believe the temperature of
cavity walls to be more reliable. The geometry and lay-
out of output device and diagnostics allowed XRD “to
see” only the inner surface of the cavity while the
straightforward radiation of the load being screened.
The temperature of the inner wall thus determined was
in the range of 38-48 eV, in some shots, it turned out to
be as high as ~ 50 eV.
5. SUMMARY
1. Scientific cooperation including TRINITI and
Kurchatov institute develops the “Baikal” project aimed
at constructing the pulsed power machine of new gener-
ation. Nowadays, experiments in Kurchatov institute are
being carried out supporting this program, in particular,
those with special output units at S-300 high-current
generator.
2. The switching rate as high as 1015 A/s =
(2.5 MA)/(2.5 ns) has been achieved by using nanosec-
ond plasma flow switch, and the quasi-steady regime of
a tiny wire-array implosion, corresponding to the cur-
rent and switching time level (750 kA)/(5 ns) with the
typical time of subsequent damping ~ 100 ns.
3. The radiative temperature of the inner wall of a
microscopic Hohlraum has been recorded as high as
~50 eV.
The work was supported by the Russian Department
of Atomic Energy and partially by the Russian Founda-
tion for Basic Research, grant 01-02-17359, and by the
Russian grant “Scientific School” NSH-2292.2003.2.
REFERENCES
1. V.V. Alexandrov, E.A. Azizov, A.V. Branitsky, et
al, “Multi-Wire Array Implosion Physics Study and
“MOL” Test-Bed for “Baikal” Project Based on
900 MJ Inductive Storage” // Proc. 13-th Int. Conf.
On High-Power Particle Beams (BEAMS’2000)
Nagaoka, Japan, June 2000, p.147.
2. V. Smirnov, A. Chernenko, K. Chukbar, et al,
“Study of Imploding Plasmas” // Proc. 18-th IAEA
Fusion Energy Conf., Sorrento, Italy, Oct. 2000,
IFP/05.
3. J.P. Quintenz et al. “Sandia’s Plans for the New
Millenium” // Proc. 13-th Int. Conf. on High Power
Beams. Nagaoka, Japan, June 2000, p. 1; see also:
C. Deeney, M.R. Douglas, R.B. Spielman, et al. //
Phys. Rev. Lett. 1998. vol. 81, p. 4883
4. [4] A.S. Kingsep, K.V. Chukbar, V.V. Yan’kov,
“Electron Magnetohydrodynamics” // Reviews of
Plasma Physics, B.B. Kadomtsev, Ed., New York:
“Consultants Bureau”, 1990, vol. 16, p.243-291.
1RRC “Kurchatov Institute”, 1 Kurchatov Sq., Moscow, 123182, Russia;
Fig.1. The sketch of output device
|
| id | nasplib_isofts_kiev_ua-123456789-111002 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1562-6016 |
| language | English |
| last_indexed | 2025-12-01T19:39:43Z |
| publishDate | 2003 |
| publisher | Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| record_format | dspace |
| spelling | Kingsep, A.S. Bakshaev, Yu.L. Bartov, A.V. Blinov, P.I. Chernenko, A.S. Chikin, R.V. Chukbar, K.V. Danko, S.A. Dubas, L.G. Kalinin, Yu.G. Kovalenko, I.V. Lobanov, A.I. Mizhiritsky, V.I. Shchagin, V.A. Smirnov, V.P. 2017-01-07T16:51:13Z 2017-01-07T16:51:13Z 2003 Experiments with the tiny nanosecond output device on the S-300 high-current generator / A.S. Kingsep, Yu.L. Bakshaev, A.V. Bartov, P.I. Blinov, A.S. Chernenko, R.V. Chikin, K.V. Chukbar, S.A. Danko, L.G. Dubas, Yu.G. Kalinin, I.V. Kovalenko, A.I. Lobanov, V.I. Mizhiritsky, V.A. Shchagin, V.P. Smirnov // Вопросы атомной науки и техники. — 2003. — № 4. — С. 26-28. — Бібліогр.: 4 назв. — англ. 1562-6016 https://nasplib.isofts.kiev.ua/handle/123456789/111002 533.9 On the S-300 pulsed power generator (4.5 MA, 70 ns, 0.15 Ohm), within the frames of ICF program based on fast high-current Z-pinches, experiments are being carried out studying promising schemes of output units. In particular, a device similar to the plasma flow switch is being investigated aimed at sharpening the pulse. In the experiments with such a device, by means of variation the geometry of the inner electrode of a co-axial, as well as the acceleration of a cascade of plasma “washers”, the switching of the current up to 750 kA has been obtained, with the rise time ~ 5…7 ns and subsequent decrease being in accordance with that of the net current (~ 100 ns). Thereby the opportunity of switching of much more amount of energy onto the load has been demonstrated compared to our preliminary experiments (2.5 MA/2.5 ns). Soft X-ray radiation from the cavity was recorded by means of vacuum diodes with a nickel cathode and especially selected filters. The radiative temperature of the cavity walls estimated from the ratio of diode signals was close to 50 eV. The work was supported by the Russian Department of Atomic Energy and partially by the Russian Foundation for Basic Research, grant 01-02-17359, and by the Russian grant “Scientific School” NSH-2292.2003.2. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Релятивистская плазменная электроника Experiments with the tiny nanosecond output device on the S-300 high-current generator Article published earlier |
| spellingShingle | Experiments with the tiny nanosecond output device on the S-300 high-current generator Kingsep, A.S. Bakshaev, Yu.L. Bartov, A.V. Blinov, P.I. Chernenko, A.S. Chikin, R.V. Chukbar, K.V. Danko, S.A. Dubas, L.G. Kalinin, Yu.G. Kovalenko, I.V. Lobanov, A.I. Mizhiritsky, V.I. Shchagin, V.A. Smirnov, V.P. Релятивистская плазменная электроника |
| title | Experiments with the tiny nanosecond output device on the S-300 high-current generator |
| title_full | Experiments with the tiny nanosecond output device on the S-300 high-current generator |
| title_fullStr | Experiments with the tiny nanosecond output device on the S-300 high-current generator |
| title_full_unstemmed | Experiments with the tiny nanosecond output device on the S-300 high-current generator |
| title_short | Experiments with the tiny nanosecond output device on the S-300 high-current generator |
| title_sort | experiments with the tiny nanosecond output device on the s-300 high-current generator |
| topic | Релятивистская плазменная электроника |
| topic_facet | Релятивистская плазменная электроника |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/111002 |
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