<abstract xmlns="http://www.w3.org/1999/xhtml"> 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 identified 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 filled 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.</abstract>

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 identified 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 filled 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.

Evolution of the small ball-like structures in the plasma focus discharge

Faculty of Electrical Engineering, Czech Technical University in Prague (CVUT), Technická 2, 166 27, Prague, Czech Republic

Institute of Plasma Physics and Laser Microfusion (IPPLM), 23 Hery Str., 01-497 Warsaw, Poland

Nukleonika

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

{"article-title":"Evolution of the small ball-like structures in the plasma focus discharge"}

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...

Evolution of the small ball-like structures in the plasma focus discharge

Published Online: Jun 15, 2016

Page range: 155 - 159

Received: Sep 24, 2015

Accepted: Dec 03, 2015

DOI: https://doi.org/10.1515/nuka-2016-0027

© by Balzhima Cikhardtova

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.