Comments on recent achievements of research on dense magnetized plasmas in Poland
This invited lecture presents author’s comments on results of the experimental studies of dense and high-temperature plasmas, which were carried out in Poland during recent two years. Those studies were performed with the PF-360U device at NCBJ, and the PF-1000U facility at IFPiLM. There were inve...
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
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irk-123456789-1488522019-02-19T01:27:45Z Comments on recent achievements of research on dense magnetized plasmas in Poland Sadowski, M.J. This invited lecture presents author’s comments on results of the experimental studies of dense and high-temperature plasmas, which were carried out in Poland during recent two years. Those studies were performed with the PF-360U device at NCBJ, and the PF-1000U facility at IFPiLM. There were investigated fast electron beams and soft x-rays, an influence of thin metal wires and/or an admixture of heavier gases, an influence of a shape of the anode end, as well as plasma micro-structures in a pinch column, i.e. plasma filaments and hot-spots (of electron densities > 10¹⁹ cm⁻³ and electron temperatures ranging several keV). The detailed studies concerned also the VR and x-ray emissions, estimates of local electron temperatures, and fast deuteron beams. Other experiments were devoted to investigation of plasma jets which can have dimensionless parameters corresponding to astrophysical objects. There are also presented some examples of the technological applications of PF discharges, studied in a frame of the Polish-Ukrainian scientific collaboration. The author’s comments are followed by proposals of some future theoretical and experimental studies. Представлено коментарі автора про результати експериментальних досліджень щільних і високотемпературних плазм, що проводилися в Польщі протягом останніх двох років. Ці дослідження проводилися на установках ПФ-360U у Національному центрі ядерних досліджень та ПФ-1000U в Інституті фізики плазми і лазерного мікросинтезу. Особливу увагу приділено вивченню швидких електронних пучків і рентгенівського випромінювання, впливу тонких металевих дротів і/або суміші важких газів, впливу форми анода, а також плазмових мікроструктур у пінчі, тобто плазмових ниток і гарячих точок з електронною густиною > 10¹⁹ см⁻³ і електронними температурами близько декількох кілоелектронвольт. Детально описано також дослідження видимого та рентгенівського випромінювань, оцінки локальних електронних температур і пучків швидких дейтронів. Інші експерименти були присвячені вивченню плазмових струменів, які мають розміри, що відповідають астрофізичним об'єктам. У рамках польсько-українського наукового співробітництва представлені деякі приклади технологічного застосування ПФ-розрядів. Автор пропонує деякі теоретичні та експериментальні ідеї для подальших досліджень у цій області. Представлены комментарии автора о результатах экспериментальных исследований плотных и высокотемпературных плазм, которые проводились в Польше в течение последних двух лет. Эти исследования проводились на установках ПФ-360U в Национальном центре ядерных исследований и ПФ1000U в Институте физики плазмы и лазерного микросинтеза. Особое внимание уделялось изучению быстрых электронных пучков и рентгеновского излучения, влияния тонких металлических проволок и/или смеси тяжелых газов, влияния формы анода, а также плазменных микроструктур в пинче, т.е. плазменных нитей и горячих точек с электронной плотностью > 10¹⁹ см⁻³ и электронными температурами порядка нескольких килоэлектронвольт. Детально описано также исследование видимого и рентгеновского излучений, оценки локальных электронных температур и пучков быстрых дейтронов. Другие эксперименты были посвящены изучению плазменных струй, которые имеют размеры соответствующие астрофизическим объектам. В рамках польско-украинского научного сотрудничества представлены некоторые примеры технологического применения ПФ-разрядов. Автор предлагает некоторые теоретические и экспериментальные идеи для последующих исследований в этой области. 2018 Article Comments on recent achievements of research on dense magnetized plasmas in Poland / M.J. Sadowski // Вопросы атомной науки и техники. — 2018. — № 6. — С. 121-126. — Бібліогр.: 28 назв. — англ. 1562-6016 PACS: 52.50.Dg; 52.58.Lq; 52.59.Hq; 52.40.Hf; 52.70.-m http://dspace.nbuv.gov.ua/handle/123456789/148852 en Вопросы атомной науки и техники Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| language |
English |
| description |
This invited lecture presents author’s comments on results of the experimental studies of dense and high-temperature
plasmas, which were carried out in Poland during recent two years. Those studies were performed with the PF-360U
device at NCBJ, and the PF-1000U facility at IFPiLM. There were investigated fast electron beams and soft x-rays, an
influence of thin metal wires and/or an admixture of heavier gases, an influence of a shape of the anode end, as well as
plasma micro-structures in a pinch column, i.e. plasma filaments and hot-spots (of electron densities > 10¹⁹ cm⁻³
and
electron temperatures ranging several keV). The detailed studies concerned also the VR and x-ray emissions, estimates of
local electron temperatures, and fast deuteron beams. Other experiments were devoted to investigation of plasma jets
which can have dimensionless parameters corresponding to astrophysical objects. There are also presented some examples
of the technological applications of PF discharges, studied in a frame of the Polish-Ukrainian scientific collaboration. The
author’s comments are followed by proposals of some future theoretical and experimental studies. |
| format |
Article |
| author |
Sadowski, M.J. |
| spellingShingle |
Sadowski, M.J. Comments on recent achievements of research on dense magnetized plasmas in Poland Вопросы атомной науки и техники |
| author_facet |
Sadowski, M.J. |
| author_sort |
Sadowski, M.J. |
| title |
Comments on recent achievements of research on dense magnetized plasmas in Poland |
| title_short |
Comments on recent achievements of research on dense magnetized plasmas in Poland |
| title_full |
Comments on recent achievements of research on dense magnetized plasmas in Poland |
| title_fullStr |
Comments on recent achievements of research on dense magnetized plasmas in Poland |
| title_full_unstemmed |
Comments on recent achievements of research on dense magnetized plasmas in Poland |
| title_sort |
comments on recent achievements of research on dense magnetized plasmas in poland |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2018 |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/148852 |
| citation_txt |
Comments on recent achievements of research on dense magnetized plasmas in Poland / M.J. Sadowski // Вопросы атомной науки и техники. — 2018. — № 6. — С. 121-126. — Бібліогр.: 28 назв. — англ. |
| series |
Вопросы атомной науки и техники |
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AT sadowskimj commentsonrecentachievementsofresearchondensemagnetizedplasmasinpoland |
| first_indexed |
2025-07-12T20:27:43Z |
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2025-07-12T20:27:43Z |
| _version_ |
1837474328355012608 |
| fulltext |
PLASMA DYNAMICS AND PLASMA-WALL INTERACTION
ISSN 1562-6016. ВАНТ. 2018. №6(118)
PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. 2018, № 6. Series: Plasma Physics (118), p. 121-126. 121
COMMENTS ON RECENT ACHIEVEMENTS OF RESEARCH ON
DENSE MAGNETIZED PLASMAS IN POLAND
M.J. Sadowski1-2
1National Centre for Nuclear Research (NCBJ), Otwock-Świerk, Poland;
2Institute of Plasma Physics and Laser Microfusion (IFPiLM), Warsaw, Poland
This invited lecture presents author’s comments on results of the experimental studies of dense and high-temperature
plasmas, which were carried out in Poland during recent two years. Those studies were performed with the PF-360U
device at NCBJ, and the PF-1000U facility at IFPiLM. There were investigated fast electron beams and soft x-rays, an
influence of thin metal wires and/or an admixture of heavier gases, an influence of a shape of the anode end, as well as
plasma micro-structures in a pinch column, i.e. plasma filaments and hot-spots (of electron densities > 1019 cm-3 and
electron temperatures ranging several keV). The detailed studies concerned also the VR and x-ray emissions, estimates of
local electron temperatures, and fast deuteron beams. Other experiments were devoted to investigation of plasma jets
which can have dimensionless parameters corresponding to astrophysical objects. There are also presented some examples
of the technological applications of PF discharges, studied in a frame of the Polish-Ukrainian scientific collaboration. The
author’s comments are followed by proposals of some future theoretical and experimental studies.
PACS: 52.50.Dg; 52.58.Lq; 52.59.Hq; 52.40.Hf; 52.70.-m
INTRODUCTION
The experimental and theoretical studies of high-
temperature plasmas in Poland were initiated about 70
years ago. They were carried out mainly at the Institute
of Nuclear Research (IBJ, later IPJ in Swierk n.
Warsaw), which in 2011 was converted in the National
Centre for Nuclear Studies (NCBJ). The Department of
Plasma Physics and Materials Engineering (PV) was
then split into the Plasma/Ion Beam Technology
Division (FM2) and Plasma Studies Division (TJ5). In
April 2018 the TJ5 department was combined with a
Department of Detectors Physics and Plasma
Diagnostics (TJ3). The results of earlier research on hot
plasmas and controlled fusion were described in many
papers and reported at international conferences,
including those held in Kharkov [1-2].
Plasma research in Poland embraced various topics,
e.g. laser experiments, tokamaks, technology etc., but
the main aim of this invited talk was to present the
author’s comments on the studies of dense magnetized
plasmas, which have been performed after the previous
conference ICPPCF-2016, and to present some new
proposals.
1. STUDIES OF FAST ELECTRON BEAMS
AND SOFT X-RAYS FROM PF
DISCHARGES
Initially some time-integrated visible radiation (VR)
pictures were compared with x-ray pinhole images in
order to identify plasma microstructures (Fig. 1).
Fig. 1. Time-integrated VR picture and x-ray pinhole
image of a PF-1000U discharge performed at
Uo = 23 kV, p0 = 1.2 hPa (D2+1% Ne) + D2 puffing [3]
During recent two years particular attention was
focussed on detailed studies of fast electron beams (e-
beams) and soft x-rays (SXR) emitted from high-current
discharges of the plasma-focus (PF) type.
Measurements with x-ray pinhole cameras and
filtered PIN diodes, which were carried out with the
PF-360U device at NCBJ (Otwock-Swierk n. Warsaw)
and the PF-1000U facility at IFPiLM (Warsaw),
demonstrated that the x-ray pinhole images show fine
plasma structures (filaments, hot-spots) in the pinch
column. The most important observations of the x-rays
and some estimates of local electron temperatures (Te)
were summarized in a lecture given at ICPPCF-2016
[3]. Measurements with different magnetic analysers
proved that the fast e-beams can get energy up to
hundreds keV, and their emission is correlated with the
formation of hot-spots [4].
2. RESEARCH ON INFLUENCE OF A THIN
METAL WIRE ON PF PINCH COLUMN
Next experimental studies concerned an influence of a
thin metal wire immersed in a PF pinch column [5]. The
Al-wire (of 270 m in diameter and 10 cm in length)
was placed along the PF-1000U electrodes axis by
means of a holder, which was fixed without any
connection with the anode.
Fig. 2. Interferometric images recorded for shot
#10633: (A) during the implosion of the current sheath
and formation of the Al-wire corona, (B) during the
formation of the internal plasmoid
122 ISSN 1562-6016. ВАНТ. 2018. №6(118)
Detailed measurements of the voltage waveforms,
current derivative, and the total discharge current vs.
time, were performed for discharges of 350 kJ energy,
at the maximal current reaching 1.5…1.7 MA. Time-
resolved SXR in the energy range of 0.7…15 keV
were measured with a Si-PIN diode filtered with a
10-m-thick Be-foil.
Time-integrated x-ray pictures were taken with a
pinhole camera equipped with the identical Be-filter.
The use was also made of a sophisticated laser
interferometer system which made it possible to obtain
up to 15 frames during a single discharge [6]. The
interferometric images of the PF-1000U discharges
were recorded at different instants and analysed in
details (Fig. 2).
The ultraviolet (XUV) radiation from PF discharges
was detected by means of a multi-channel plate (MCP)
without any filter, which could record photons of energy
> 10 eV [5]. A comparison of the XUV and
inteferometric images provided additional and valuable
information about transformations of the pinch column
(Fig. 3).
Fig. 3. Images of a plasma column and the wire corona:
(A) a XUV frame, and (B) an interferometric image,
taken during the first SXR and neutron pulse: (C)
another XUV frame taken at the late phase of the XUV
emission [5]
An important finding was the observation that the
insertion of the Al-wire does not prevent the formation
of dense plasmoids and the production of fusion-
neutrons during transformations of the PF column, if the
corona is not broken [5].
The next experiments with the Al-wire placed along
the pinch axis in the PF-1000U facility were performed
at the helium-filling [7]. Such discharges have also
produced pinches containing spontaneously organized
structures of the helical-, toroidal- and plasmoidal-type,
but dynamics was considerably slower. The production
of hard x-ray (HXR) pulses was different, since in the
D-shots they were generated mainly during the
instability evolution, while in the He-discharges they
were emitted during the formation of the first internal
plasmoid [7].
In author’s opinion the use of a metal wire is not a
good method for the optimization of PF discharges,
since the introduction of relatively cold metal ions
reduces the neutron yield (Yn). It might be reasonable to
perform experiments with the use of a frozen-deuterium
wire, which might be completely vaporized and increase
the deuterons density, as in some Z-pinch experiments
[8].
3. STUDIES OF INFLUENCE OF N2
ADMIXTURE ON EVOLUTION OF A D2
PINCH COLUMN
The next series of experiments concerned research on
an influence of a heavier gas (e.g. nitrogen) admixture on
dynamics of a pinch column [9]. Detailed interferometric
measurements enabled different phases of the pinch
transformation to be investigated (see Fig. 4).
Fig. 4. Interferometric images corresponding to
different phases: (A) implosion of a constriction, (B) the
minimal constriction diameter, (C) expansion and HXR
emission, (E) pinch interruption (formation of separate
plasmoids). The presented part of the pinch column is
5 cm in length
Measurements of the XUV radiation, as performed
with the framed MCP, provided interesting information
about filamentation of the pinch column (Fig. 5).
Fig. 5 XUV images recorded at various instants:
(A) -72 ns, (B) +58 ns, (C) +74 ns, and the
interferometric image (D) which shows some filaments
in the top corners
It was found that the current filaments, as recorded
during the implosion and the pinch phase, had 1…2 mm
in diameter and the electron density ranging
(3…7)·1024 m-3. Reconnections of magnetic field lines
(originating from such current filaments) induced strong
electrical fields, which could accelerate electrons and
ions to energies of hundreds kiloelectronvolt [9]. These
processes influenced also on the DD fusion reactions
rate and neutron yields.
In author’s opinion the current filaments, which can
easily be observed in discharges with the application of
a heavier gas admixture, are indeed responsible for the
generation of strong magnetic fields. Transformations of
these magnetic fields can induce strong local electric
fields responsible for the acceleration of ions and
electrons, but one should also take into account local
disruptions of filaments, when the separation of
electrical charges in dense plasma can also induce very
strong local electric fields [10]. Such disruptions
(filaments necks) can form point-like sources of fast
deuteron beams.
ISSN 1562-6016. ВАНТ. 2018. №6(118) 123
4. STUDIES OF FILAMENTATION
PHENOMENA
The studies described in Section 3 were followed by
detailed observations of current filaments in the pinched
column of PF-1000 discharges at the D-filling and D-
puffing [11]. There were observed many plasma
filaments and hot-spots (lasting > 50 ns), which moved
within a plasma stream. For the first time there were
observed very small “plasma balls” outside the pinch
column, which appeared during the early discharge
phases (Fig. 6).
Fig. 6. XUV and interferometric images of early phases:
(A-D) during the current sheath implosion, (E-H)
during the emission of the 1st peaks of x-rays and
neutrons [11]
Many tiny plasma filaments and “plasma balls” were
also observed in the XUV frames recorded during the
late phases 100…200 ns of the PF-1000 discharges [11].
Similar observations were performed at D-filling and H-
puffing, as well as at H-filling and D-puffing, but in
general the described micro-structures were more
distinct when a heavier gas admixture was applied [11].
In author’s opinion the observed plasma micro-
structures, visible in the XUV frames, can hardly be
identified in the interferometric images due to their
small dimensions and too small gradients in the electron
density. The observed tiny plasma filaments can have
various directions (from quasi-axial to quasi-radial),
what probably depends on the direction of an Ampere
force (of the discharge current and its own magnetic
field) or a Hall current (depending on the main
discharge electric- and magnetic-fields). It should be
remind that the quasi-axial filaments inside the pinch
column were for the first time observed many years ago
in other PF and Z-pinch experiments [12, 13]. The
author is convinced that research on plasma-current
filaments and hot-spots should be continued, and new
efforts should be undertaken to develop corresponding
physical models.
In a frame of the Czech-Polish scientific
collaboration there were performed studies of
transformations of the ordered internal plasma structures
during the acceleration of fast charged particles in PF
discharges [14]. The collected data provided detailed
information about pinch dynamics and other
characteristics (Fig. 7).
The reported studies confirmed that the 1st neutron
pulse is produced by fast deuterons accelerated by
transformations of the internal plasma structures, and it
is emitted during formation of the 1st plasmoid, while
the subsequent neutron pulses are generated later,
during the development of strong instabilities.
In author’s opinion these statements are consistent
with conclusions from earlier experiments performed
within other PF facilities [15], but new information is
provided by high-quality intereferometric images.
Fig. 7. Waveforms: (a) dI/dt (thick grey), SXR (thin
grey), HRX (thin black), neutrons (dashed), (b) signals
from scintillation detectors: downstream (black),
upstream (grey), and side-on (dashed); Interferometric
images: (c) formation of a plasmoid, (d-f) formation of
necking [14]
5. INVESTIGATION OF AN INFLUENCE OF
A CONICAL TIP PLACED IN THE ANODE-
CENTRE
The next PF-1000 experiments concerned research
on an influence of a shape of the anode end. A metal
conical tip was fixed at the centre of the anode end-plate
[16]. It changed the formation of the pinch column and
its characteristics (Fig. 8).
Fig. 8. VR picture, showing that current filaments had
quasi-stabile positions upon the anode surface, and the
pinch column had a distinct micro-structure
Measurements of the I(t) and dI/dt waveforms, the
SXR and HXR peaks, as well as detailed studies of the
pinch structure by means of the laser interferometer,
were also performed (Fig. 9).
124 ISSN 1562-6016. ВАНТ. 2018. №6(118)
Fig. 9. Interferometric images of different phases of a
discharge with the anode conical ending: (c-e) the
stagnation phase, (i-k) a decay of the internal plasmoids
The use of the metal tip facilitated motion of current
filament upon the anode surface, and influenced the
pinch formation, and dynamics of the internal plasma
micro-structures. For a comparison, during the reported
experiments, there were performed 16 shots without any
anode-tip and 29 shots with the conical tip [16]. The
average value of Yn increased from (0.8 ± 0.3) · 1010 to
(5.3 ± 2.0) · 1010, but a jitter in Yn was also increased.
In author’s opinion the observed increase in Yn could
be induced by changes in the dimensions and dynamics
of the pinch column, but one should remember about
erosion of the anode surface and an inflow of metal
ions. It should also be noted that conical tips were
applied in earlier PF experiments [17], to produce more
stable hot-spots, which served as local sources of fast
electrons and x-rays.
6. STUDIES OF VR, X-RAYS (FOR
ESTIMATES OF LOCAL TE), AND FAST
DEUTERONS
The earlier studies of the VR and x-ray emission
from PF discharges (see above) were followed by more
detailed investigation of the optical spectra, x-ray
pulses, and fast deuteron beams [18]. The optical
emission spectroscopy (OES) was applied to record the
Balmer D-lines and lines of impurities (Fig. 9).
Fig. 10. OES spectra recorded vs. time after a current
dip
Attention was focused on time-integrated and time-
resolved measurements of the SXR emission. X-ray
signals were collected by two pairs of filtered PIN
diodes which observed the chosen regions of the pinch
column (see as shown in Fig. 1). The SRX signals were
compared, and Te values (averaged over the observation
regions) were estimated. They depended on
experimental conditions, i.e. the pressure and
composition of working gas (Fig. 11).
Fig. 11. X-ray signals from two pairs of PIN diodes and
different shots: (left) at 1.2 hPa D2 + D2 puffing, (right)
at 1.2 hPa (90 %D2+10 %Ne) + (75 %D2+25 %Ne)
puffing
The research described above was followed by
detailed studies of fast deuterons and fusion-neutrons
[20]. The measurements of the characteristic discharge
waveforms were supplemented by the laser
interferometry and measurements of deuteron beams,
which were performed by means of pinhole cameras
equipped with nuclear track detectors (Fig. 12).
Fig. 12. Waveforms: (a) current derivative (thick grey),
SXR (thin grey), HXR (black), fusion neutrons (dashed);
(b) Deuteron images (> 360 keV, at 600 and 00);
Interferograms: (c) before the x-ray and neutron pulse,
(d) during the pinch interruption, (e-g) after that
The most important was the statement that the fast
deuterons are emitted as numerous beams from different
pinch regions and tops of plasma lobules, formed
outside the dense plasma column. Trajectories of these
deuterons are strongly deflected by local magnetic
fields.
In author’s opinion the described studies are
consistent with earlier ion measurements, but should be
followed by more detailed investigation. The SXR
signals should be taken from smaller plasma regions,
which can be defined by appropriate pinholes. The
emitted ions should be measured in more details in
order to determine their mass- and energy spectra, as
well as their dependence on the experimental
conditions.
-0,1 0,0 0,1 0,2 0,3
-0,5
-0,4
-0,3
-0,2
-0,1
0,0
550 eV
265 eV
110 eV
115 eV
P
IN
d
io
d
y
,
V
t, s
#11493
210 eV
Be 7 m, z = 6 cm
Be 10 m, z = 6 cm
Be 10 m, z = 3 cm
Be 7 m, z = 3 cm
ISSN 1562-6016. ВАНТ. 2018. №6(118) 125
7. STUDIES OF DEUTERIUM AND HELIUM
PLASMA JETS IN PF DISCHARGES
The recent studies of dense magnetized plasmas
concerned also the generation of so-called plasma jets
[21-22]. The scientific collaboration of the Polish and
Russian teams enabled the formation of a dense plasma
jet to be observed (Fig. 13).
Fig. 13. Time-integrated picture of a plasma jet
generated in the PF-1000U facility by a discharge
#11541 at p0 = 1.2 hPa D2, U0 = 16 kV, and
Imax = 1.4 MA
Those studies showed that such plasma jets can have
dimensionless parameters, i.e. the Mach-, Reynolds- and
Pécklet-numbers as well as density contrasts
(njet/nambient), similar to those observed in astrophysical
objects [21]. It was also shown that the simulation of
some astrophysical jets in a laboratory is possible with
the use of different PF facilities (in Moscow, Warsaw,
and Sukhumi) [22].
Recently, more detailed studies of the influence of
gas conditions on parameters of plasma jets generated in
the PF-1000U facility have been performed and
summarised in a new paper [23].
In author’s opinion such experiments are of primary
importance for further simulations of astrophysical
phenomena, but one should take into account
considerable differences in parameters of plasmas
generated within various PF machines. An attempt
should be undertaken to obtain the best consistence of
characteristic parameters.
8. APPLICATIONS OF DENSE PLASMA
STREAMS FROM PF DISCHARGES
During recent years the experimental studies, which
concerned applications of plasma streams produced by
PF discharges, were performed in a frame of the
bilateral Polish-Ukrainian scientific collaboration. As an
example one can mention investigation of plasma
interactions with tungsten samples in the PF-1000U
facility [24], but it should also be noted that studies of
plasma-surface interactions were also carried out with
other plasma facilities, e.g. the RPI-IBIS in Swierk [25]
and QSPA in Kharkov [26, 27]. Other examples of the
material studies are reported in another presentation at
the ICPPCF-2018 [27].
9. SUMMARY AND CONCLUSIONS
The detailed comments on described research
activities have been given in the previous sections. The
most important comments can be summarised as
follows: 1. A thin axial metal-wire can slightly increase
an averaged Yn, but an inflow of metal ions changes
other emission characteristics; 2. Filaments and hot-
spots constitute important forms of the internal plasma
structures, and they should be further investigated
experimentally and theoretically; 3. The use of a conical
tip upon the anode improves slightly parameters of the
pinch column, but the problem is strong erosion of this
tip surface; 4. The ordered internal plasma structures in
PF discharges have already been investigated, but more
experimental data and theoretical analyses are still
needed; 5. Simultaneous measurements of x-rays, e-
beams and fast ions, coupled with detailed
interferometric studies, have already been performed,
but their precision should still be improved; 6.
The generation of dense plasma jets in PF facilities
has been studied, but some optimization of this process
is still needed; 7. Applications of dense plasma streams
for material engineering have been investigated, but
they should still be further developed.
On basis of the reported results the author has
proposed to perform new PF experiments with the use
of a frozen-deuterium fibre. Also proposed are further
detailed studies of filaments and hot-spots. Since these
phenomena do not preserve the cylindrical symmetry, it
is necessary to apply a 3D mhd-code or to develop a
more sophisticated model, e.g. kinetic approach.
Transformations of other internal plasma structures
require also a theoretical analysis. More precise
measurements of x-rays, e-beams and fast ions should
also be performed, and the generation of plasma jets
should be studied in more details. Applications of PF
facilities for material engineering should be extended on
new materials. It would be reasonable to realize such
advanced studies in a frame of research activities at the
International Centre for Dense Magnetized Plasmas.
ACKNOWLEDGEMENTS
The reported studies were supported by Grants MSMT
LTT17015, LTAUSA17084, GACR 16-070365, IAEA
CRP RC-19253, and SGS 16/223/OHK3/3T/13 in
Czech Republic, the RSF Project No. 16-12-10051 in
Russia, IAEA CRP RC-23071 in Poland and the
financial resources allocated by the Polish Ministry of
Science and Higher Education for inter-national co-
financed projects at IFPILM in years 2017-2018.
REFERENCES
1. M.J. Sadowski // PAST. 2014, № 6(20), p. 245-249.
2. M.J. Sadowski, J. Zebrowski // PAST. 2016, № 6(22),
p. 291-296.
3. E. Skladnik-Sadowska et al. // PAST. 2016, № 6(22),
p. 112-116.
4. W. Surala // Ph.D. Thesis (NCBJ, Swierk 2016).
5. P. Kubeset et al. // Phys. Plasmas. 2016, v. 23,
p. 062702.
6. E. Zielinska et al. // Contrib. Phys. 2011, 51, p. 279-
283.
7. P. Kubes et al. // Phys. Plasmas. 2016, v. 23,
p. 112708.
8. J.D. Sethian et al. // Phys. Rev. Lett. 1987, v. 59,
p. 892-895.
9. P. Kubes et al. // Phys. Plasmas. 2016, v. 23,
p. 082704.
10. M.J. Sadowski, M. Scholz // Plasma Sources Sci.
Technol. 2008, v. 17, p. 024001.
11. P. Kubes et al. // Phys. Plasmas. 2017, v. 24,
p. 032706.
126 ISSN 1562-6016. ВАНТ. 2018. №6(118)
12. M. Sadowski et al. // Phys. Letters. 1984, v. 105A,
p. 117-123.
13. A. Pasternak et al. // Czech. J. Phys. 2000, v. 50,
Suppl. 3, p. 159-163.
14. P. Kubes et al. // Phys. Plasmas. 2017, v. 24,
p. 072706.
15. L. Bertalot et al. // Plasma Phys. Contr. Nucl.
Fusion Res. 1980, v. 2, p. 177-185.
16. P. Kubes et al. // Phys. Plasmas. 2017, v. 24,
p. 092707.
17. L. Jakubowski et al. // Proc. Intern. Conf. Plasma
Phys / Nagoya, 1996, v. 2, p. 1326-1329.
18. D.R. Zaloga // Ph. D. Thesis (NCBJ, Swierk 2017).
19. D.R. Zaloga et al. // J. Phys.: Conf. Ser. 2018,
v. 959, p. 012003.
20. P. Kubes et al. // Phys. Plasmas. 2018, v. 25,
p. 012712.
21. E. Skladnik-Sadowska et al. // Phys. Plasmas. 2016,
v. 23, p. 122902.
22. V.I. Krauz et al. // J. Phys.: Conf. Ser. 2017, v. 907,
p. 012026.
23. E. Skladnik-Sadowska et al. // Phys. Plasmas. 2018,
v. 25, p. 082715.
24. M.S. Ladygina et al. // Nukleonika. 2016, 61, p. 149-
153.
25. I.E. Garkusha et al. // Physica Scripta. 2016, v. 91,
p. 094001.
26. A. Marchenko et al. // J. Phys.: Conf. Ser. 2018,
v. 959, p. 012006.
27. I.E. Garkusha et al. // J. Phys.: Conf. Ser. 2018,
v. 959, p. 012004.
28. A. Marchenko et al. // Proc. ICPPCF. Kharkiv,
2018.
Article received 13.09.2018
КОММЕНТАРИИ О ПОСЛЕДНИХ ДОСТИЖЕНИЯХ В ИССЛЕДОВАНИИ ПЛОТНЫХ
ЗАМАГНИЧЕННЫХ ПЛАЗМ В ПОЛЬШЕ
M.J. Sadowski
Представлены комментарии автора о результатах экспериментальных исследований плотных и
высокотемпературных плазм, которые проводились в Польше в течение последних двух лет. Эти
исследования проводились на установках ПФ-360U в Национальном центре ядерных исследований и ПФ-
1000U в Институте физики плазмы и лазерного микросинтеза. Особое внимание уделялось изучению
быстрых электронных пучков и рентгеновского излучения, влияния тонких металлических проволок и/или
смеси тяжелых газов, влияния формы анода, а также плазменных микроструктур в пинче, т.е. плазменных
нитей и горячих точек с электронной плотностью > 1019 см-3 и электронными температурами порядка
нескольких килоэлектронвольт. Детально описано также исследование видимого и рентгеновского
излучений, оценки локальных электронных температур и пучков быстрых дейтронов. Другие эксперименты
были посвящены изучению плазменных струй, которые имеют размеры соответствующие астрофизическим
объектам. В рамках польско-украинского научного сотрудничества представлены некоторые примеры
технологического применения ПФ-разрядов. Автор предлагает некоторые теоретические и
экспериментальные идеи для последующих исследований в этой области.
КОМЕНТАРІ ПРО ОСТАННІ ДОСЯГНЕННЯ В ДОСЛІДЖЕННІ ГУСТИХ ЗАМАГНІЧЕНИХ
ПЛАЗМ У ПОЛЬЩІ
M.J. Sadowski
Представлено коментарі автора про результати експериментальних досліджень щільних і
високотемпературних плазм, що проводилися в Польщі протягом останніх двох років. Ці дослідження
проводилися на установках ПФ-360U у Національному центрі ядерних досліджень та ПФ-1000U в Інституті
фізики плазми і лазерного мікросинтезу. Особливу увагу приділено вивченню швидких електронних пучків і
рентгенівського випромінювання, впливу тонких металевих дротів і/або суміші важких газів, впливу форми
анода, а також плазмових мікроструктур у пінчі, тобто плазмових ниток і гарячих точок з електронною
густиною > 1019 см-3 і електронними температурами близько декількох кілоелектронвольт. Детально описано
також дослідження видимого та рентгенівського випромінювань, оцінки локальних електронних температур
і пучків швидких дейтронів. Інші експерименти були присвячені вивченню плазмових струменів, які мають
розміри, що відповідають астрофізичним об'єктам. У рамках польсько-українського наукового
співробітництва представлені деякі приклади технологічного застосування ПФ-розрядів.
Автор пропонує деякі теоретичні та експериментальні ідеї для подальших досліджень у цій області.
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