M.J. Sadowski

M.J. Sadowski
National Centre for Nuclear Research · Plasma Studies Division (TJ5)

Professor

About

394
Publications
37,163
Reads
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3,398
Citations
Additional affiliations
September 2011 - present
National Centre for Nuclear Studies (NCBJ)
Position
  • Research
January 2011 - present
National Centre for Nuclear Research
Position
  • Professor
January 1993 - present
Institute of Plasma Physics and Laser Microfusion
Education
May 1969 - June 1976
Institute of Nuclear Research (IBJ)
Field of study
  • Plasma physics
February 1960 - April 1969
Institute of Nuclear Research (IBJ)
Field of study
  • Plasma physics
September 1958 - June 1963
Warsaw University of Technology
Field of study
  • Electrical Engineering

Publications

Publications (394)
Article
Filament-like structures were observed during discharges in a small 3-kJ plasma focus device operated with pure deuterium. These structures were recorded by means of two different laser diagnostic techniques: a schlieren system and a differential laser interferometry. They present the novel fine-scale (submillimeter) plasma structures recorded duri...
Article
Fifteen-frames interferometric diagnostics at the PF-1000 facility was enhanced by adding four frames of the schlieren diagnostics and by splitting of four channels in the optical delay line. This setup enabled the visualization of gradients in the plasma density perpendicular to the direction of the diagnostic laser beam, and their relationship wi...
Article
This paper concerns the correlation of hard x-ray and neutron signals, which were recorded with scintillation detectors oriented in the axial and radial directions, in a comparison with interferometric and extreme-ultraviolet radiation frames, as recorded within the plasma focus (PF)-1000 facility operated with a deuterium filling. The considered s...
Article
Full-text available
The beams of fast runaway electrons (RE), which are often produced during tokamak discharges, are particularly dangerous and can induce serious damages of the vacuum vessel and internal components of the machine. The proper and fast diagnostics of RE beams is essential for controlling the discharge, e.g., by early mitigation of disruptions and pote...
Article
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This paper is a sequel to the 1998 review paper “Scientific status of the Dense Plasma Focus” with 16 authors belonging to 16 nations, whose initiative led to the establishment of the International Center for Dense Magnetized Plasmas (ICDMP) in the year 2000. Its focus is on understanding the principal defining characteristic features of the plasma...
Article
The paper characterizes sources of the fast deuterons which can produce the D–D fusion neutrons. Two pinhole cameras, the axial one and the slant one (oriented at 0° and 60° in relation to the z-axis), were equipped with solid-state nuclear track detectors and applied to investigate the fast deuterons of energies about 100 keV, which produce small...
Article
Full-text available
The paper presents the most important results of recent plasma studies performed within the PF-1000U facility at the IPPLM in Warsaw, Poland. It was shown that a conical-tip of the anode facilitates the pinch formation and induces an increase in the total neutron yield, while the use of an anti-anode shortens the pinch column, but does not improve...
Article
This paper describes the structure of a higher extreme ultraviolet (XUV) emission and plasma density region which surrounds a pinched dense-plasma column. It is interpreted as a toroidal-like plasma formation, which is flowing by a closed current with poloidal and toroidal components upon its surface. This current produces a local magnetic field, w...
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The paper discusses a possible energy transformation that leads to the acceleration of fast ions and electrons. In plasma-focus discharges that occur during deuterium filling, which have a maximum current of about 1 MA, the accelerated deuterons produce fast fusion neutrons and fast electrons hard X-ray emissions. Their total energy, which is of th...
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This paper concerns the evolution of internal structures and the neutron production in plasma-focus discharges performed in the presence of a permanent magnet (placed inside the anode front) and within a residual magnetic field (after the removal of this magnet). The initial magnetic field generated by this magnet prevented: (i) the effective compr...
Article
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The paper summarizes important results of the recent experimental studies performed on the plasma-focus PF-1000 facility operated in Warsaw, Poland, mainly with the pure deuterium filling. Attention is focused on the evolution of toroidal and plasmoidal self-organized structures formed by internal closed currents inside the dense plasma column. The...
Article
This paper presents the discussion concerning the characteristics of the fast deuterons which have energy above 30 keV and are recorded during high-current plasma-focus (PF) discharges, by means of PM-355 plastic track-detectors placed inside ion pinhole cameras. The fast deuterons evoke D-D fusion reactions, mainly by a beam-target mechanism. The...
Article
Full-text available
The use of tungsten (W) as the main plasma facing component (PFC) was proposed for fusion reactors many years ago. Our recent experiments have been focused on spectroscopic studies of tungsten properties under its irradiation by intense plasma streams. Several samples made of pure W or (90 %W + 10 %Cu) alloy have been exposed to deuterium and argon...
Article
Plasma in a pinch column, as produced by a plasma-focus discharge at the deuterium filling and the current intensity reaching 1 MA, was investigated at the total neutron yield reaching about 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> per discharge. The use was made of neutron diagnosti...
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The damage of deformed double forged pure tungsten (W) and tungsten alloyed with 5 wt.% tantalum (WTa5) have been studied in experimental simulations of ITER-like transient events (surface heat load of 0.45 MJ/m 2 and the pulse duration of 0.25 ms) with quasi-stationary plasma accelerator QSPA Kh-50. The plasma exposures were performed for targets...
Article
Several series of high-current discharges were carried out within the PF-1000U facility at various gas conditions. The initial filling pressures were p0 = 1.2 hPa D2, 1.06 hPa D2 + 10% He, or 0.53 hPa D2 + 25% Ne. The discharges were performed with or without an additional gas puffing. In shots with the puffing, 1 cm³ of gas (or mixture), compresse...
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Full-text available
The paper describes the behaviour of plasma within a MA plasma-focus with a novel electrode configuration, in which the anode and anti-anode were both equipped with conical tips. This configuration was applied to test the possibility of reducing the pinch axial dimensions during the radial compression of a current sheath. It made it possible to str...
Article
Full-text available
This paper considers regions of a fast deuteron production in a correlation with an evolution of ordered structures inside a pinch column of a mega-ampere plasma focus discharge. Ion pinhole cameras equipped with plastic PM-355 track-detectors recorded fast deuterons escaping in the downstream and other directions (up to 60° to the z-axis). Time-in...
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Influence of powerful plasma impacts on several materials used for the construction of energy systems, i.e. different grades of steels as well as tungsten coatings, has been discussed. Irradiations of these materials with hydrogen and helium plasma streams have been performed in several high-current-pulse and quasi-stationary plasma accelerators wh...
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Full-text available
In the reported studies the attention was focused on an analysis of optical spectra of the visible radiation emitted from stainless steel (SS) samples exposed to intense pulses from a ND:YAG laser or pulsed plasma streams produced by a Rod Plasma Injector (RPI) IBIS. Operational regimes of the RPI IBIS facility, which can generate intense deuterium...
Article
Full-text available
The paper concerns measurements of runaway electrons (REs) which are generated during discharges in tokamaks. The control of REs is an important task in experimental studies within the ITER-physics program. The NCBJ team proposed to study REs by means of Cherenkov-type detectors several years ago. The Cherenkov radiation, induced by REs in appropri...
Article
Full-text available
The paper reports on soft x-ray emission from high-current discharges in PF-1000U facility operated at 170 kJ. The discharges at static conditions were performed with pure deuterium (D2) and a mixture of D2 and neon (Ne). In shots with the gas-puffing 1 cm³ of D2 or a (D2+Ne) mixture was injected 2 ms before the discharge initiation. Time-integrate...
Article
Direct measurements of fast electrons, which are produced in high-temperature plasma and escape from tokamak-type facilities, are of particular interest for ITER and future fusion devices, where intense runaway electrons (RE) can significantly damage the first wall components. Therefore, the runaway control and mitigation based on credible measurin...
Article
Full-text available
Results are presented from laboratory simulations of plasma jets emitted by young stellar objects carried out at the plasma focus facilities. The experiments were performed at three facilities: the PF-3, PF-1000U and KPF-4. The operation modes were realized enabling the formation of narrow plasma jets which can propagate over long distances. The ma...
Article
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The paper describes the evolution of self-organized structures inside a pinched plasma column during the phase of the effective production of fusion neutrons, as observed in the mega-ampere plasma focus experiment performed with a conical tip placed in the centre of the anode face. In a comparison with the plane anode face configuration, the descri...
Article
Full-text available
The paper concerns important differences in the evolution of plasma column structures during the production of fusion neutrons in the first and subsequent neutron pulses, as observed for plasma-focus discharges performed with the deuterium filling. The first neutron pulse, of a more isotropic distribution, is usually produced during the formation o...
Article
Full-text available
The paper describes the filamentary structure observed in the high-energy ultraviolet radiation for discharges performed at the hydrogen- or deuterium-filling and at the puffing of hydrogen, deuterium or helium, in a mega-ampere dense plasma-focus facility. The lifetime of this structure overcomes 50 ns. These filaments connect the surface of a pin...
Article
Optical emission spectroscopy techniques were used to investigate the spectra of dense deuterium-plasma jets generated by high-current pulse discharges within the large PF-1000U facility and to estimate parameters of plasma inside the jets and their surroundings. Time-resolved optical spectra were recorded by means of a Mechelle®900 spectrometer. F...
Article
The paper describes the evolution of the ordered dense toroidal- and plasmoidal-like structures in a pinch column and the hard X-ray emission from mega-ampere dense plasma-focus discharges performed at the helium (He) filling. Some shots were carried out with an Al-wire of 270 μm in diameter, which was placed along the z-axis in the front of the an...
Article
Full-text available
This paper is devoted to plasma–surface interaction issues at high heat-loads which are typical for fusion reactors. For the International Thermonuclear Experimental Reactor (ITER), which is now under construction, the knowledge of erosion processes and the behaviour of various constructional materials under extreme conditions is a very critical is...
Article
The paper presents results of experimental studies of dense and high-temperature plasmas, which were produced by pulsed high-current discharges within a modernised PF-1000U facility operated at different initial gas conditions, and supplied from a condenser bank which delivered energy of about 350 kJ. The investigated discharges were performed at t...
Article
Full-text available
The application of a mixture of nitrogen and deuterium for the gas-puffing along the anode axis in deuterium plasma-focus discharges, as carried out at megaampere-level currents, enabled observations of the filamentary structure, and the decrease in the transformation velocity of the plasma column to be performed. It made possible to investigate th...
Article
Full-text available
In this paper, we describe the influence of an Al wire of 270 μm in diameter placed along the anode axis on the transformation of the deuterium pinch column in a megaampere (MA) plasma focus device. The evolution of the pinched column and of the wire corona was investigated by means of the multiframe interferometry, neutron and X-ray diagnostics. T...
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Full-text available
This paper present results of optical spectroscopy studies of interactions of intense plasma streams with a solid target made of carbon fibre composite (CFC). The experiments were carried out within the Rod Plasma Injector (RPI) IBIS facility. The optical measurements were performed first for a freely propagating plasma stream in order to determine...
Article
Full-text available
This paper presents results of experimental studies of tungsten samples of 99.95% purity, which were irradiated by intense plasma-ion streams. The behaviour of tungsten, and particularly its structural change induced by high plasma loads, is of great importance for fusion technology. The reported measurements were performed within a modified PF-100...
Article
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The paper reports results of the recent experimental studies of pulsed electron beams and soft X-rays in plasma-focus (PF) experiments carried out within a modified PF-360U facility at the NCBJ, Poland. Particular attention was focused on time-resolved measurements of the fast electron beams by means of two different magnetic analyzers, which could...
Article
The article presents the results concerning the OES characterization of plasmoids generated by the Impulse Plasma Deposition method modified by the use of gas injection (Gas Controlled IPD). Both of the electrodes of the coaxial accelerator: the tube (cathode) and the rod (anode – the source of the vapors) are permanently connected with the capacit...
Article
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This invited lecture presents comments on the most important results of high-temperature plasma studies which have been carried out at the NCBJ, Poland, since the ICPPCF-2014. The main scientific tasks concerned studies of fast electrons, ions, neutrons, and x-rays emitted from different research facilities of the PF-, RPI-, ICF- and Tokamak-type a...
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The invited paper reports on measurements of soft x-rays emitted from hot plasmas produced in a modernised PF-1000U facility. The discharges were performed at the D2-filling with or without a Ne-admixture, under the initial pressure of 0.9 or 1.5 Torr and at the initial charging voltage equal to 16 or 18 kV. Time-integrated x-ray images were record...
Article
Full-text available
Results from a Cherenkov probe recently installed in FTU are presented on non-thermal electron losses. A range of scenarios are investigated to prove the versatility of the diagnostics by correlation with several other diagnostics, including electron cyclotron emission (ECE), neutron and gamma ray detectors, Mirnov coils and soft x-ray cameras. The...
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Full-text available
Since the 2012 IAEA-FEC Conference, FTU operations have been largely devoted to runaway electrons generation and control, to the exploitation of the 140 GHz electron cyclotron (EC) system and to liquid metal limiter elements. Experiments on runaway electrons have shown that the measured threshold electric field for their generation is larger than p...
Article
Full-text available
This work reports on recent experiments performed at the modernized PF-1000U plasma-focus facility. In contrast to earlier studies the main attention was focussed on measurements of the soft x-ray emission. Detailed time-integrated x-ray measurements, carried out using filtered pinhole cameras with sensitive x-ray films, are presented and analysed....
Conference Paper
Full-text available
The paper presents results of time-resolved measurements of fast deuterons emitted from high-current discharges of the Plasma-Focus (PF) type. The measurements were performed in a modified PF-1000U facility which is operated at the IFPiLM in Warsaw, Poland. The device was equipped with a fast-acting gas valve placed inside the inner electrode and o...
Conference Paper
Full-text available
The paper presents feasibility and design studies of Cherenkov-type probes, a development of the measuring head construction designed for different tokamak devices, and in particular the acquisition of optical signals to a data storage system. In order to lower the energy threshold of the electron detection the authors applied radiators with the hi...
Article
Full-text available
In this note we describe measurements of ion beams emitted along the z-axis of the DPF-1000U facility operated at 23 kV, 334 kJ, and with the initial deuterium pressure of 1.6-2 hPa. The DPF-1000U device was recently renewed and equipped with a dynamic gas-puff valve placed inside the inner electrode. The investigated ions were recorded by means of...
Article
Full-text available
Soft X-ray imaging is a very useful diagnostic technique in plasma-focus (PF) experiments. This paper reports results of four experimental sessions which were carried out at the DPF-1000U plasma-focus facility in 2013 and 2014. Over 200 discharges were performed at various experimental conditions. Measurements were taken using two X-ray pinhole cam...
Article
Full-text available
In this note experimental studies of tungsten (W) samples irradiated by intense plasma-ion streams are reported. Measurements were performed using the modified plasma focus device DPF-1000U equipped with an axial gas-puffing system. The main diagnostic tool was a Mechelle®900 optical spectrometer. The electron density of a freely propagating plasma...
Article
Full-text available
This paper concerns important and difficult problems connected with a design and construction of thermonuclear reactors, which have to use nuclear fusion reactions of heavy isotopes of hydrogen, i.e., deuterium (D) and tritium (T). There are described conditions in which such reactions can occur, and different methods of a high-temperature plasma g...
Article
Full-text available
The results are presented of the optical spectra measurements for free plasma streams generated with the use of the modified DPF-1000U machine. This facility was recently equipped with a gas injection system (the so-called gas-puff) placed on the symmetry axis behind the central opening in the inner electrode. The DPF-1000U experimental chamber was...
Article
Full-text available
This invited paper considers reasons why exact measurements of fast electron and ion losses in tokamaks, and particularly i n a scrape-off-layer and near a divertor region, are necessary in order to master nuclear fusion energy production. Attention is also paid to direct measurements of escaping fusion products from D-D and D-T reactions, and in p...
Conference Paper
Full-text available
The paper reports on recent measurements of the X-ray emission from a large plasma-focus PF-1000U facility [1] and compares them with results from the old Poseidon device [2]. The most important results of time-integrated measurements, which were performed by means of an X-ray pinhole camera, are presented and analyzed. Attention is paid to studies...
Conference Paper
Full-text available
Measurements of fast electrons produced in plasma and escaping from tokamak-type facilities are of particular interest for diagnostics, because such electrons deliver information about processes occurring inside bulk plasma. A team from the National Centre for Nuclear Research (NCBJ, former IPJ) proposed Cherenkov-type probes for measurements of fa...
Conference Paper
Full-text available
Uncontrolled rapid loss of runaway current represents one of the most critical issues in tokamak reactors. Significant research efforts are necessary to study and understand efficient ways to control Runaway Electrons (REs) and to implement adequate control schemes to prevent disruptions. In this context, the aim of the study presented here is to i...
Article
Full-text available
The paper presents some outcomes obtained during the year of 2013 of the activity in the frame of the International Atomic Energy Agency Co-ordinated research project »Investigations of Materials under High Repetition and Intense Fusion-Relevant Pulses». The main results are related to the effects created at the interaction of powerful pulses of di...
Article
Full-text available
Experimental simulations of ITER-like transient events with relevant surface heat load parameters (energy density up to 1.1 MJ/m2 and the pulse duration of 0.25 ms) as well as particle loads (varied in wide range from 1023 to 1027 ion/m2 s) were carried out with a quasistationary plasma accelerator QSPA Kh-50. Particular attention was paid to elabo...
Article
Full-text available
The paper concerns fast protons and neutrons from D-D fusion reactions in a Plasma-Focus-1000U facility. Measurements were performed with nuclear-track detectors arranged in “sandwiches” of an Al-foil and two PM-355 detectors separated by a polyethylene-plate. The Al-foil eliminated all primary deuterons, but was penetrable for fast fusion protons....
Article
Full-text available
The main aim of the reported experimental session was to study operational characteristics of a modified PF-1000U facility during a free propagation of a plasma-stream and its interactions with a carbon-fiber composite (CFC) target. The facility was equipped with an axial fast-acting valve for additional gas puffing into a region close to the elect...