Generation of multiply charged ions from a cathode jet of a low-energy vacuum spark

Abstract

Ion parameters in a cathode plasma jet of a vacuum spark with a discharge energy of a few joules were measured. The studies were performed by a time-of-flight method with the help of an energy analyser. It was found that the discharge plasma generated a short-run beam of multiply charged ions of the cathode material at the initial stage of the discharge firing. The ions had charge states from Z = + 1 up to Z = + 18. When the initial capacitor voltage was varied within the ranges of 0.3-2.5 kV, the mean ion charge increased from +4.3 to +9.0.

Spark generation of monometallic and bimetallic aerosol nanoparticles

“…It is interesting that even if the ionization potential of the anode material was lower than that of the cathode material, the generation rate of the anode metal particles was higher than that of the cathode metal particles. This might be caused by higher temperature channel formed near the anode and thus higher evaporation and subsequent nucleation/condensation near the anode (Artamonov et al, 2001;Borra et al, 1998;Krasik et al, 2006). On the other hand, for the Pd-Ag sparks (Ag(+) : Pd(−) and Pd(+) : Ag(−)), Pd always had a higher fraction than Ag regardless of the electrode polarity.…”

“…A spark channel is formed when the applied voltage is beyond a critical value. This results in the generation of energetic electrons and ions (Artamonov, Krasov, & Paperny, 2001;Holland, 1956;Krasik et al, 2006; Marusina & Filimonenko, 1984), which collide with the anode and cathode (Borra, Goldman, Goldman, & Boulaud, 1998), respectively. Metal atoms are detached from the electrodes by ion bombardment (sputtering).…”

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

“…The latter usually stem from adsorbates on surfaces of the discharge system. Occasionally very high metal charges states such as Au 19+ have been claimed to be extracted [128,138,139], however, it is much more likely that those ions are actually low ion charge states of desorbed gases. This statement is based on both theoretical considerations of ionization and recombination [124] as well as my own practical attempts using pulsed vacuum discharges up to 75 kA, which led to extracted charge states of "only" up to 7+ [140,141].…”

High charge state ions extracted from metal plasmas in the transition regime from vacuum spark to high current vacuum arc

“…Ultimately, this effort was terminated because the non-metal contribution to the beam was always large (and not fully understood). Another effort was done more recently by Paperny's team [18,19] using a vacuum spark with a copper cathode. One has to deal with the principle difficulty of measuring mass/charge, and so it is not easy, and in some cases impossible, to resolve the peaks of multiply charged metal and light non-metal ions.…”