Local regions of high-pressure plasma in a vacuum spark

Negus, C. R.; Peacock, N J

doi:10.1088/0022-3727/12/1/011

Cited by 83 publications

(33 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A phenomenon called radiative collapse leads to the formation of high density plasma hot spots that emit x-rays characteristic of highly charged ions, e.g. helium-like Fe XXIV [119], molybdenum Mo XL [120], or magnesium Mg X [121]. Such phenomena are very different from vacuum arcs.…”

Section: Vacuum Arc and Vacuum Sparksmentioning

confidence: 99%

The evolution of ion charge states in cathodic vacuum arc plasmas: a review

Anders¹

2012

Plasma Sources Sci. Technol.

View full text Add to dashboard Cite

ACKNOWLEDGMENTMany of the here-collected results are based on ideas and contributions by close friends and colleagues. Running the risk of offending those not mentioned, I gratefully acknowledge the input over the years from just a few: B. Jüttner, E. Hantzsche, P. Siemroth, T. Schülke, I. Brown, E. Oks and G. Yushkov. This work was supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. DISCLAIMERThis document was prepared as an account of work sponsored by the United States Government. While this document is believed to contain correct information, neither the United States Government nor any agency thereof, nor The Regents of the University of California, nor any of their employees, makes any warranty, express or implied, or assumes any legal responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by its trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or The Regents of the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof or The Regents of the University of California. 2The evolution of ion charge states in cathodic vacuum arc plasmas: a review André AndersLawrence Berkeley National Laboratory, 1 Cyclotron Road, MS 53, Berkeley, California 94720, USA Email: aanders@lbl.gov AbstractCathodic vacuum arc plasmas are known to contain multiply charged ions. 20 years after "Pressure Ionization: its role in metal vapour vacuum arc plasmas and ion sources" appeared in vol. 1 of Plasma Sources Science and Technology, it is a great opportunity to re-visit the issue of pressure ionization, a non-ideal plasma effect, and put it in perspective to the many other factors that influence observable charge state distributions, such as the role of the cathode material, the path in the density-temperature phase diagram, the "noise" in vacuum arc plasma as described by a fractal model approach, the effects of external magnetic fields and charge exchange collisions with neutrals. A much more complex image of the vacuum arc plasma emerges putting decades of experimentation and modeling in perspective.

show abstract

Section: Vacuum Arc and Vacuum Sparksmentioning

confidence: 99%

The evolution of ion charge states in cathodic vacuum arc plasmas: a review

Anders¹

2012

Plasma Sources Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…Indeed, bursts of hard X rays emitted by hydrogen-or helium-like ions of the cathode material (iron or titanium) were detected even in early experiments [4]. According to the current notion, these ions are generated in micron-size regions of a high-temperature plasma with an electron temperature of up to a few kiloelectronvolts [5]. The formation of such regions is attributed to plasma pinching that occurs in the plasma jet closing the interelectrode gap when the discharge current reaches its maximum.…”

Section: Introductionmentioning

confidence: 99%

Micropinches in plasma flame expanding into vacuum ambient

et al. 2006

View full text Add to dashboard Cite

Results of experimental and theoretical studies of plasma parameters in a currentcarrying plasma flame expanding into the vacuum ambient are presented. It is shown that at the initial stage of the discharge burning the short-run beams of multiply charged ions of the cathode material (with mean ion charge state up +9 for Cu) were emitted from the cathode plasma flame. The X-ray pinhole measurements showed that a small-size area of hot electron with a temperature of 100 ÷ 200 eV was formed at a range of about 2 ÷ 3 mm from the cathode. A theoretical model is developed of the process of the currentcarrying cathode plasma flame expansion. A set of hydrodynamic equations was solved numerically by the particle-in-cell method. It was shown that due to the Ampere forces a neck was formed at a distance from the cathode that was developed to a micropinch, where electron temperature attained of about 100 eV and the beams of multiply charged ions of the cathode material were produced. Both the temporal and space parameters of the micropinch formation are consistent with results of the measurements. The mean ion charge state of the ions also is in agreement with the experimental data.PACS : 52.58.Lq

show abstract

“…The emission of hard x-rays (HXR) with photon energies greater than 5 keV is a common feature in Z-pinch discharges such as vacuum sparks [1][2][3], plasma focus [4,5], gas-puff [6,7], X-pinch [8][9][10][11] and wire array [12][13][14][15][16]. The previous studies showed that X-pinch had emitted HXR continuum and characteristic line radiations due to interaction of energetic electron beams with matter [11].…”

Section: Introductionmentioning

confidence: 99%