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Temporal distribution of linear densities of the plasma column in a plasma focus discharge

Cikhardtova B., Kubeš P., Cikhardt J., Paduch M., Zielinska E., Kravárik J., Řezáč K., Kortanek J., Šíla O.

Nukleonika

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2015

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Vol. 60, No. 2

315--318

EN

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.

2

New magnetic anomalies of the Outer Carpathians in NE Slovakia and their relationship to the Carpathian Conductivity Zone

Kucharič L., Bezák V., Kubeš P., Konečný V., Vozár J.

Geological Quarterly

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2013

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Vol. 57, No. 1

123–-134

EN

A hitherto unknown magnetic anomaly has been detected in the framework of assembling magnetic picture of the Slovakian territory. The impressive magnetic object was recognized in the northeasternmost part of Slovakia within the area which is created by sediments of the Flysch belt. This is certain rarity because the Flysch sequence is practically without magnetic rocks. Due to this was obvious that anomaly is caused by an exotic rocks complex, intruded into Flysch sediments. The shape and the character of anomalous body indicated that source of anomaly is located in the shallow depth under surface relatively. The anomaly has been modelled in the 2D. Source of magnetic anomaly was interpreted as the product of Neogene volcanism – neck of intermediate rocks. Besides of this there were found out other minor anomalies within this area which might be caused also by smaller subvolcanic bodies. The Carpathian Conductivity Anomaly is located in the proximity of new observed magnetic anomalies. Due to this fact it is possible to open new view on the importance of this zone. In the case of justification of such interpretation the area might be interesting for its potential prognosis of hydrocarbons occurrence, metallogenetic prominence, as well as possibilities for underground storage of carbon dioxide.

3

Progress in MJ plasma focus research at IPPLM

Scholz M., Karpinski L., Krauz V. I., Kubeš P., Paduch M., Sadowski M. J.

Nukleonika

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2012

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Vol. 57, No. 2

183-188

EN

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.

4

Interferometry of the plasma focus equipped with forehead cathode

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.

Nukleonika

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2012

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Vol. 57, No. 2

189-192

EN

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.

5

Measurements of electron and ion beams emitted from the PF-1000 device in the upstream and downstream direction

Kwiatkowski R., Skladnik-Sadowska E., Malinowski K., Sadowski M. J., Czaus K., Zebrowski J., Karpinski L., Paduch M., Scholz M., Garkusha I. E., Kubeš P.

Nukleonika

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2011

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Vol. 56, No. 2

119-123

EN

In this paper we report on measurements of the energy spectra and other properties of the electron and fast ion beams emitted in the upstream and downstream direction along the z-axis of a large plasma focus device PF-1000, that was operated at 21-27 kV, delivering 290–480 kJ pulse. Measurements of the electron beam (EB) properties were performed using a magnetic analyzer. Properties of the ion beams were measured by means of pinhole cameras equipped with PM-355 nuclear track detectors and placed at various angles (0, 60 and 180 centigrade) to the discharge axis. Measurements revealed a complex spatial structure of the fast ion beams. The ion measurements behind the PF-1000 collector proved that some fast deuterons are emitted also in the upstream direction. Measurements of the EBs emitted in the upstream and downstream direction revealed electron energies in the range from approximately 40 keV to approximately 800 keV. These spectra confirm that in localized regions within the PF-1000 plasma column there appear strong fields accelerating charged particles in different directions along the discharge axis.

6

Status of a mega-joule scale Plasma-Focus experiments

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.

Nukleonika

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2006

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Vol. 51, nr 1

79-84

EN

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.

7

Energy transformation in Plasma Focus discharge with wire and liner as a load

Kubeš P., Kravárik J., Klír D., Scholz M., Paduch M., Tomaszewski K., Karpinski L., Ryc L., Juha L., Krása J., Szydlowski A., Romanova V.

Nukleonika

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2002

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Vol. 47, nr 4

151-153

EN

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.

8

Stabilizing of Z-pinch and Plasma Focus discharges due to thick wires

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.

Nukleonika

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2001

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Vol. 46, nr 1

5-7

EN

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.