Ion charge state distributions in high current vacuum arc plasmas in a magnetic field

Окс, Е. М.; Anders, André; Brown, Ian; Dickinson, M.R.; MacGill, R.A.

doi:10.1109/27.533127

Cited by 166 publications

(99 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has been shown [2] that the application of a strong axial magnetic field in the vicinity of the cathode leads to an increase in the metal ion charge states in the plasma, but a mechanism for this phenomenon was not proposed. The influence of magnetic field on the normalized ion current is shown on Fig.…”

Section: Lbnl-58199mentioning

confidence: 99%

See 1 more Smart Citation

Measurement of total ion current from vacuum arc plasma sources

Окс

Savkin

Yushkov

et al. 2006

Review of Scientific Instruments

Self Cite

View full text Add to dashboard Cite

The total ion current generated by a vacuum arc plasma source was measured. The discharge system investigated allowed ion collection from the arc plasma streaming through a hemispherical mesh anode with geometric transparency of 72%. A range of different cathode materials was investigated, and the arc current was varied over the range 50-500 A. We find that the normalized ion current (I ion /I arc ) depends on the cathode material, with values in the range from 5% to 19% and generally greater for elements of low cohesive energy. The application of a strong axial magnetic field in the cathode and arc region leads to increased normalized ion current, but only by virtue of enhanced ion charge states formed in a strong magnetic field.

show abstract

Section: Lbnl-58199mentioning

confidence: 99%

“…In the usual mode of operation the beam contains virtually only metal ions, with minimal gaseous ion impurity content. Application of a strong axial magnetic field in the cathode and arc region increases the metal ion charge states in the plasma and the extracted ion beam current [2].…”

Section: Introductionmentioning

confidence: 99%

Measurement of total ion current from vacuum arc plasma sources

Окс

Savkin

Yushkov

et al. 2006

Review of Scientific Instruments

Self Cite

View full text Add to dashboard Cite

show abstract

“…[1][2][3][4][5] The charge states can be shifted higher by a number of measures like the application of a magnetic field. 6,7 This was shown to be related to greater power dissipation because the burning voltage of the discharge, measured between anode and cathode, is greatly enhanced. Furthermore, it is also known that charge states can be shifted to lower values by the interaction with background gas neutrals 8,9 and neutrals (vapor) of the cathode material.…”

Section: Introductionmentioning

confidence: 99%

Physical limits for high ion charge states in pulsed discharges in vacuum

Yushkov

Anders

2009

Journal of Applied Physics

View full text Add to dashboard Cite

Short-pulse, high-current discharges in vacuum were investigated with the goal to maximize the ion charge state number. In a direct extension of previous work [Appl.Phys. Lett. 92, 041502 (2008)], the role of pulse length, rate of current rise, and current amplitude was studied. For all experimental conditions, the usable (extractable) mean ion charge state could not be pushed beyond 7+. Instead, a maximum of the mean ion charge state (about 6+ to 7+ for most cathode materials) was found for a power of 2-3 MW dissipated in the discharge gap. The maximum is the result of two opposing processes that occur when the power is increased: (i) the formation of higher ion charge states, and (ii) a greater production of neutrals (both metal and non-metal), which reduces the charge state via charge exchange collisions.2

show abstract

“…The influence of the magnetic field is significant for external fields while the magnetic self-field can be neglected as long as the current is relatively low (<200 A [9] and < 500 A [10]). The self-field must be taken into account for highcurrent (kA) arcs [10].…”

Section: Introductionmentioning

confidence: 99%

“…The charge state distributions are material dependent and the ion mean charge can be reduced by the presence of background gas [5][6][7][8] or enhanced by magnetic fields [9][10][11]. The influence of the magnetic field is significant for external fields while the magnetic self-field can be neglected as long as the current is relatively low (<200 A [9] and < 500 A [10]). The self-field must be taken into account for highcurrent (kA) arcs [10].…”

Section: Introductionmentioning

confidence: 99%

Ion charge state fluctuations in vacuum arcs

Anders¹,

Fukuda²,

Yushkov³

2005

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

Abstract. Ion charge state distributions of cathodic vacuum arcs have been investigated using a modified time-of-flight method. Experiments have been done in double gate and burst gate mode, allowing us to study both systematic and stochastic changes of ion charge state distributions with a time resolution down to 100 ns. In the double gate method, two ion charge spectra are recorded with a well-defined time between measurements. The elements Mg, Bi, and Cu were selected for tests, representing metals of very different properties. For all elements it was found that large stochastic changes occur even at the limit of resolution. This is in agreement with fast changing arc properties observed elsewhere. Correlation of results for short times between measurements was found but it is argued that this is due to velocity mixing rather than due to cathode processes. The burst mode of time-of-flight measurements revealed the systematic time evolution of ion charge states within a single arc discharge, as opposed to previous measurements that relied on data averaged over many pulses. The technique shows the decay of the mean ion charge state as well as the level of material-dependent fluctuations.

show abstract

Ion charge state distributions in high current vacuum arc plasmas in a magnetic field

Cited by 166 publications

References 28 publications

Measurement of total ion current from vacuum arc plasma sources

Measurement of total ion current from vacuum arc plasma sources

Physical limits for high ion charge states in pulsed discharges in vacuum

Ion charge state fluctuations in vacuum arcs

Contact Info

Product

Resources

About