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Wyświetlanie 1-15 z 19
Tytuł:
Recent progress in 1 MJ Plasma-Focus research
Autorzy:
Scholz, M.
Karpiński, L.
Paduch, M.
Tomaszewski, K.
Miklaszewski, R.
Szydlowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/147553.pdf
Data publikacji:
2001
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
neutron emission
plasma focus
scaling laws
soft X-ray radiation
Opis:
The paper reports on actual operational characteristics of the PF-1000 facility and it presents results of the first neutron experiments performed with a new set of large Mather-type electrodes, which were designed for shots up to 1000 kJ. Dynamics of a current-sheath was studied by means of two high-speed streak cameras and a two-frame camera. The last one was used for the side-on observation of the pinch column. The high-speed streak pictures were taken side-on behind slits oriented in the radial or axial direction. On the basis of the pictures taken behind the radial slit, average values of the radial compression and expansion velocities were estimated. Time-resolved X-ray signals were measured with PIN diodes covered by different filters, and they were compared with other traces (voltage waveforms, dI/dt signals, and neutron-induced pulses) in order to determine their correlation. The total neutron yield (Ytot), i.e. the number of neutrons produced during a single discharge and emitted in various directions, was measured by means of several silver-activation detectors placed at different angles around the PF-1000 experimental chamber.
Źródło:
Nukleonika; 2001, 46, 1; 35-39
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Progress in MJ plasma focus research at IPPLM
Autorzy:
Scholz, M.
Karpinski, L.
Krauz, V. I.
Kubeš, P.
Paduch, M.
Sadowski, M. J.
Powiązania:
https://bibliotekanauki.pl/articles/147514.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
plasma focus
PF-1000 facility
magnetic probes
interferometry
neutron yield scaling
Opis:
The results of studies of the plasma dynamics and neutron emission on a PF-1000 facility in the stage of pinch formation are presented. The measurements were performed using various modifications of the calibrated magnetic probes, 16 frame interferometry, silver activation counters and photomultiplier tube (PMT) neutron probes. The current measurements at a distance of 40 mm from the axis of the electrodes was measured. This dependence agrees well with the known scaling, Yn similar to I4. The evolution plasma density during pinch formation and a neutron emission were study.
Źródło:
Nukleonika; 2012, 57, 2; 183-188
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A method for the determination of spatial electron density distribution in great Plasma-Focus devices
Autorzy:
Kasperczuk, A.
Paduch, M.
Pisarczyk, T.
Tomaszewski, K.
Powiązania:
https://bibliotekanauki.pl/articles/147148.pdf
Data publikacji:
2002
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
bremsstrahlung radiation
electron density distribution
frame optical camera
plasma-focus device
plasma radiation intensity
shadowgraphy
Opis:
Determination of the electron density of plasma generated in a great plasma-focus device by means of interferometry is very difficult or sometimes impossible. In order to determine spatial electron density distributions of plasma in a PF-1000 device, a special method was prepared, with the use of plasma images obtained by means of both an optical frame camera and shadowgraphy. Analysis of plasma radiation in the very narrow Äë = 60 Ĺ optical range allowed us to determine the relation between intensity of the plasma radiation and the electron density. It was also shown that the influence of electron temperature on plasma radiation is not large. The presented method allowed us to obtain spatial electron density distributions of plasma (in relative units) in the PF-1000 device. By means of this method a number of important information about the plasma-focus phenomenon was obtained.
Źródło:
Nukleonika; 2002, 47, 1; 23-26
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Temporal distribution of linear densities of the plasma column in a plasma focus discharge
Autorzy:
Cikhardtova, B.
Kubeš, P.
Cikhardt, J.
Paduch, M.
Zielinska, E.
Kravárik, J.
Řezáč, K.
Kortanek, J.
Šíla, O.
Powiązania:
https://bibliotekanauki.pl/articles/147356.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
plasma focus (PF)
plasma pinch
plasma diagnostics
Opis:
Experiments were carried out on the PF-1000 plasma focus device, with a deuterium filling and with deuterium puffing from a gas-puff nozzle placed on the axis of the anode face. The current was reaching 2 MA. 15 interferometric frames from one shot were recorded with a Nd:YLF laser and a Mach–Zehnder interferometer, with 10–20 ns delay between the frames. As a result, the temporal and spatial distribution of the linear densities and the radial and axial velocities of the moving of plasma in the dense plasma column could be estimated.
Źródło:
Nukleonika; 2015, 60, 2; 315-318
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Status of a mega-joule scale Plasma-Focus experiments
Autorzy:
Scholz, M.
Bieńkowska, B.
Borowiecki, M.
Ivanova-Stanik, I.
Karpiński, L.
Stępniewski, W.
Paduch, M.
Tomaszewski, K.
Sadowski, M.
Szydłowski, A.
Kubeš, P.
Kravárik, J.
Powiązania:
https://bibliotekanauki.pl/articles/147496.pdf
Data publikacji:
2006
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
plasma focus
dense magnetized plasma
neutron yield
Opis:
This paper presents results of the recent plasma-focus (PF) experiments carried out with PF facilities, which was operated at energies ranging from 0.5 MJ to about 1 MJ. Particular attention has been paid to pinch evolution, the emission of pulsed X-ray, fast electron beams, and fusion produced neutrons. Some theoretical models of the initial breakdown, which occurs at the insulator surface, are compared. It is pointed out that modeling of the breakdown is sensitive to kinetics of ionization processes and transport coefficients. Progress in experimental studies of the axial acceleration phase is unsatisfactory. Important experimental data have been collected, but new measurements are still needed. For the radial collapse phase, it was shown that the MHD modeling is efficient until the maximum compression, but plasma instabilities require more sophisticated approaches. The pinch phase was investigated by means of different diagnostics. Fusion neutron yields were measured in different experiments, but some discrepancies in scaling must still be explained. The conclusions concern directions for further studies and optimization of large-scale high-current PF facilities.
Źródło:
Nukleonika; 2006, 51, 1; 79-84
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evolution of the small ball-like structures in the plasma focus discharge
Autorzy:
Cikhardtova, B.
Kubes, P.
Cikhardt, J.
Paduch, M.
Zielinska, E.
Kravarik, J.
Rezac, K.
Kortanek, J.
Powiązania:
https://bibliotekanauki.pl/articles/146922.pdf
Data publikacji:
2016
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
dense plasma focus (DPF)
interferometric diagnostics
organized structures in plasma
plasmoids
Opis:
The experiments were carried out in the PF-1000 plasma-focus device at the maximum current reaching about 2 MA, at the deuterium or neon filling and with deuterium injected from a gas-puff nozzle placed on the axis of the anode face. Ball-like structures of diameters of 1–12 mm were identifi ed in interferometric and XUV pinhole camera frames. We made the statistical description of their parameters. A lifetime of the ball- -like structures was in the range from 30 to 210 ns, and in some cases even more. These structures appeared mostly at the surface of the imploding plasma shell and they did not change their position in relation to the anode end. During the evolution of these structures, interferometric fringes were observed near the surfaces of the structures only, and their internal parts were initially chaotic (without noticeable) fringes. Subsequently the number of interferometric fringes increased (the internal ‘chaotic’ area was fi lled with fringes too) and later on it decreased. The radii of the ball-like structures were mostly increasing during their existence. The maximum electron density reached the value of 1024 to 1025 m–3. The ball-like structures decayed by absorption inside the expanded pinch column and/or gradually expired in rare plasma outside of the dense plasma column.
Źródło:
Nukleonika; 2016, 61, 2; 155-159
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experiments and simulations on the possibility of radiative contraction/collapse in the PF-1000 plasma focus
Autorzy:
Akel, M.
Cikhardt, J.
Kubes, P.
Kunze, H.-J.
Lee, S.
Paduch, M.
Saw, S. H.
Powiązania:
https://bibliotekanauki.pl/articles/147275.pdf
Data publikacji:
2016
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
plasma focus
radiative collapse
radiation losses
simulations
Opis:
Experimental studies of discharges in the plasma focus facility with neon filling and respective numerical simulations employing the radiative Lee code are reported. The pinch currents exceed the Pease-Braginskii current, which indicates that radiative losses are larger than heating and that contraction of the formed plasma should occur. Both of these effects were indeed observed. Parallel numerical simulations were crucial for the identifi cation of such an effect.
Źródło:
Nukleonika; 2016, 61, 2; 145-148
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energy transformation in Plasma Focus discharge with wire and liner as a load
Autorzy:
Kubeš, P.
Kravárik, J.
Klír, D.
Scholz, M.
Paduch, M.
Tomaszewski, K.
Karpinski, L.
Ryc, L.
Juha, L.
Krasa, J.
Szydlowski, A.
Romanova, V.
Powiązania:
https://bibliotekanauki.pl/articles/147107.pdf
Data publikacji:
2002
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
plasma focus
X-ray source
XUV spectroscopy
Opis:
We present the results of experiments focused on energy transformations during the implosion of the hydrogen current sheath towards an Al wire (120 ěm in diameter) positioned on the top of the inner electrode of the PF-1000 plasma focus facility at the IPPLM in Warsaw. A wire corona is formed at the current sheath impact and ~60 ns after the impact a soft X-ray pulse is emitted. Its spectrum contains AlVI-XII lines accompanied by their satellites. The amount of emitted energy is recorded by two filtered PIN diodes and thermoluminescent dosimeters and depends on symmetry of the current sheath and quality of the current sheath focus. The mean value of energy of keV photons emitted in the runs done without the wire (~1 J) is higher than the energy obtained with the wire (~0.4 J). A time delay between the impact of the current sheath and X-ray pulse, the plasma focus dynamics and soft X-ray emission are interpreted by an axial magnetic field generation and transformations.
Źródło:
Nukleonika; 2002, 47, 4; 151-153
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Interferometry of the plasma focus equipped with forehead cathode
Autorzy:
Kubeš, P.
Klír, D.
Rezac, K.
Paduch, M.
Pisarczyk, T.
Scholz, M.
Chodukowski, T.
Kalinowska, Z.
Hitschfel, J.
Kortanek, J.
Kravárik, J.
Ivanova-Stanik, I.
Bienkowska, B.
Karpinski, L.
Zielinska, E.
Sadowski, M. J.
Tomaszewski, K.
Powiązania:
https://bibliotekanauki.pl/articles/147512.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
interferometry
neutron diagnostics
plasma focus discharge
Opis:
The PF-1000 plasma-focus facility in Warsaw, equipped with Mather-type coaxial electrodes working with a deuterium filling, was modified by the addition of a cathode disk in front of the anode front-plate at a distance of 3 cm. The plasma was diagnosed with temporal resolved interferometry and neutron diagnostics. The modified electrode configuration showed an increase of the current in the pinch phase and a decrease of the total neutron yield. The lower total neutron yield is caused by a lower energy of deuterons producing the observed neutrons and by a decrease of the velocity of transformations of the structures in the pinch column.
Źródło:
Nukleonika; 2012, 57, 2; 189-192
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stabilizing of Z-pinch and Plasma Focus discharges due to thick wires
Autorzy:
Kubeš, P.
Kravárik, J.
Paduch, M.
Tomaszewski, K.
Scholz, M.
Karpinski, L.
Szydlowski, A.
Bakshaev, Y.
Blinov, P.
Chernenko, A. S.
Gordeev, E. M.
Dan’ko, S. A.
Korolev, V. D.
Shashkov, A.
Tumanov, V. I.
Romanova, V.
Klír, D.
Powiązania:
https://bibliotekanauki.pl/articles/146991.pdf
Data publikacji:
2001
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
plasma focus
X-ray source
XUV spectroscopy
Z-pinch
Opis:
This paper presents the results of the diagnostics observing the impact of the plasma sheath imploded in megaamper Z-pinch or plasma focus devices onto the Al or C wires of 30-300 mi m in diameter fixed in the center axis. The discharges were operated with a maximum current of 1.5-3 MA at two devices, PF 1000 at IPFLM in Warsaw, and Stand 300 at RRC Kurchatov Institute in Moscow. At the plasma impact the 10-50 ns XUV pulse was emitted in K-shell lines from the ring or helical-like forms on the surface of the wire corona. The scenario of the production of the non-equilibrium intensities of the C and Al H-like and He-like lines is discussed considering fast transformation of magnetic field, electron beams acceleration, total ionization of the ions and fast recombination in dense and magnetized wire corona.
Źródło:
Nukleonika; 2001, 46, 1; 5-7
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preliminary determination of angular distribution of neutrons emitted from PF-1000 facility by indium activation
Autorzy:
Jednoróg, S.
Szydłowski, A.
Scholz, M.
Paduch, M.
Bienkowska, B.
Powiązania:
https://bibliotekanauki.pl/articles/146918.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
plasma focus
neutron activation technique
plasma diagnostics
Opis:
This paper presents a new method applied to measure the angular neutron emission from Plasma Focus (PF) - type deuterium discharges performed within the PF-1000 facility. Neutrons were recorded by activation of especially optimized (mass and shape) indium samples with subsequent gamma spectrometry to measure the induced activity of the samples. The neutron fluence rate on every indium sample used was determined using neutron transport calculation and measured activity of the samples.
Źródło:
Nukleonika; 2012, 57, 4; 563-568
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
PF-6 an effective plasma focus as a source of ionizing radiation and plasma streams for application in material technology, biology and medicine
Autorzy:
Gribkov, V.
Dubrovsky, A.
Scholz, M.
Jednorog, S.
Karpiński, L.
Tomaszewski, K.
Paduch, M.
Miklaszewski, R.
Pimenov, V.
Ivanov, L. I.
Dyomina, E. V.
Maslyaev, S. A.
Orlova, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/147424.pdf
Data publikacji:
2006
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
dense plasma focus (DPF)
ion beam
plasma beam
X-ray beams
surface damage
microlithography
radioenzymology
positron emission tomography (PET)
Opis:
A review of results on the design and operation of the new efficient Dense Plasma Focus device PF-6 of medium size (transportable) having bank energy of ca. 7 kJ and possessing a long lifetime is presented. New data on the interaction of the pulsed fast ion beams and dense plasma streams generated at this apparatus with various materials are given. These results are compared with the analogous information received at the biggest facility PF-1000. It is shown that it is possible to have about the same power flux density (in the range of 105 109 W/cm2) in both devices however in different areas. Doses of soft X-rays produced by the device within the resists for the goals of microlithography and micromachining appear to be several times less that it is with the conventional X-ray tube. In biological application of this device, medium- and hard-energy X-rays are exploited in the field of radioenzymology. It was found that the necessary dose producing activation/inactivation of enzymes can be by several orders of magnitude lower if used at a high-power flux density in comparison with those received with isotope sources. In medicine, short-life isotope production for the goals of the positron emission tomography (medicine diagnostics) is possible by means of the fast ions generated within DPF. All these experiments are discussed in the framework of pulsed radiation physics and chemistry in its perfect sense thereto the criteria are formulated.
Źródło:
Nukleonika; 2006, 51, 1; 55-62
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recent measurements of soft X-ray emission from the DPF-1000U facility
Autorzy:
Surała, W.
Sadowski, M. J.
Paduch, M.
Zielinska, E.
Tomaszewski, K.
Powiązania:
https://bibliotekanauki.pl/articles/148171.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
plasma focus
X-ray emission
X-ray images
gas puffing
filaments
hot spots
Opis:
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 cameras with a line of sight perpendicular to the z-axis, at different azimuthal angles (about 20° and 200°), and looking towards the centre of the PF-pinch column. They were equipped with diaphragms 1000 μm or 200–300 μm in diameter and coated with filters of 500 μm Al foil and 10 μm Be foil, respectively. Data on the neutron emission were collected with silver activation counters. For time-resolved measurements the use was made of four PIN diodes equipped with various fi lters and oriented towards the centre of the PF-column, in the direction perpendicular to the electrode axis. The recorded X-ray images revealed that when the additional gas-puff system is activated during the discharge, the stability of the discharge is improved. The data collected in these experiments confi rmed the appearance of a filamentary fi ne structure in the PF discharges. In the past years the formation of such fi laments was observed in many Z-pinch type experiments. Some of the recorded X-ray images have also revealed the appearance of the so-called hot- -spots, i.e. small plasma regions of a very intense X-ray emission. Such a phenomenon was observed before in many PF experiments, e.g. in the MAJA-PF device, but it has not been investigated so far in a large facility such as the DPF-1000U. The time-resolved measurements provided the evidence of a time lapse between the X-ray emission from plasma regions located at different distance from the anode surface. The formation of distinct ‘hot-spots’ in different instants of the DPF-1000U discharge was also observed.
Źródło:
Nukleonika; 2015, 60, 2; 303-308
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Neutron and fast ion emission from PF-1000 facility equipped with new large electrodes
Autorzy:
Szydlowski, M.
Scholz, M.
Karpinski, L.
Sadowski, M.
Tomaszewski, K.
Paduch, M.
Powiązania:
https://bibliotekanauki.pl/articles/147301.pdf
Data publikacji:
2001
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
fast ion beam
neutron emission anisotropy
neutron yield
plasma focus
Opis:
A PF-1000 facility was operated for the first time at an energy level of up to 1 MJ. The maximal emission of 2×1011 neutrons/shot was registered. Relatively low emission anisotropy was observed. Fast ion beams were generated only from shots performed at a low filling pressure (1-2 Torr).
Źródło:
Nukleonika; 2001, 46, suppl. 1; 61-64
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new concept of fusion neutron monitoring for PF-1000 device
Autorzy:
Jednorog, S.
Laszynska, E.
Bienkowska, B.
Ziolkowski, A.
Paduch, M.
Szewczak, K.
Mikszuta, K.
Malinowski, K.
Bajdel, M.
Potrykus, P.
Powiązania:
https://bibliotekanauki.pl/articles/148394.pdf
Data publikacji:
2017
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
dense plasma focus (DPF)
PF-1000
neutron diagnostic
activation technique
Opis:
The power output of plasma experiments and fusion reactors is a crucial parameter. It is determined by neutron yields that are proportional and directly related to the fusion yield. The number of emitted neutrons should be known for safety reasons and for neutron budget management. The PF-1000 is the large plasma facility based on the plasma focus phenomenon. PF-1000 is operating in the Institute of Plasma Physics and Laser Microfusion in Warsaw. Neutron yield changes during subsequent pulses, which is immanent part of this type device and so it must be monitored in terms of neutron emission. The reference diagnostic intended for this purpose is the silver activation counter (SAC) used for many years. Our previous studies demonstrated the applicability of radio-yttrium for neutron yield measurements during the deuterium campaign on the PF-1000 facility. The obtained results were compared with data from silver activation counter and shown linear dependence but with some protuberances in local scale. Correlation between results for both neutron monitors was maintained. But the yttrium monitor registered the fast energy neutron that reached measurement apparatus directly from the plasma pinch. Based on the preliminary experiences, the yttrium monitor was designed to automatically register neutron-induced yttrium activity. The MCNP geometrical model of PF-1000 and yttrium monitor were both used for calculation of the activation coefficient for yttrium. The yttrium monitor has been established as the permanent diagnostic for monitoring fusion reactions in the PF-1000 device.
Źródło:
Nukleonika; 2017, 62, 1; 17-22
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 19

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