Influence of a current jump on vacuum arc parameters

Charge state dependence of cathodic vacuum arc ion energy and velocity distributions

“…2 Extensive studies concerning the ion energy or velocity have been performed, primarily dealing with the most likely ion velocity, 3 the ion velocity distribution (IVD), 1 or the IED, [4][5][6][7] generally averaged over all ion species present. Investigations that enable charge-state-resolved characterization usually involve time-of-flight (TOF) techniques [8][9][10][11] and electrostatic field methods. [12][13][14][15][16][17][18][19] Generally, reports based on TOF techniques indicate charge state independence of the velocity (distribution), [8][9][10][11] whereas energy (distributions) obtained by electrostatic methods support the notion of charge state dependence.…”

“…Investigations that enable charge-state-resolved characterization usually involve time-of-flight (TOF) techniques [8][9][10][11] and electrostatic field methods. [12][13][14][15][16][17][18][19] Generally, reports based on TOF techniques indicate charge state independence of the velocity (distribution), [8][9][10][11] whereas energy (distributions) obtained by electrostatic methods support the notion of charge state dependence. [12][13][14][15][16][17][18] Literature reports where both the IEDs and the IVDs are presented for the same cathodic arc system are not available.…”

Ion flux from vacuum arc cathode spots in the absence and presence of a magnetic field

“…Earlier work indicated that there is a slight dependence of the ion velocity on the ion charge state which lead to the assumption of the "potential hump" hypothesis according to which ions are accelerated by the electric field of the hump 10,11 . More recent velocity measurements using current-perturbation methods show that the ion velocities in vacuum arcs are practically independent of charge states 6,12,13 . Consequently, a hydrodynamic ion acceleration mechanism seems to be responsible for the high ion velocities.…”

“…Ions can be extracted from the plasma allowing researchers to combine the time-offlight measurement in the plasma with the charge-state-resolving time-of-flight (TOF) method in the ion beam 6,12,13 . The perturbation can be a "current jump 12 ," or "spike 13 ," or a sequence of spikes 14 , or the forced rapid extinction of the arc discharge 15 , or a "gentle" modulation of the arc current 6 . The latter has the advantage that the perturbation has only a minor effect on the arc voltage, power balance, ion charge state distribution, ion velocity and other parameters.…”

Charge-state-resolved ion energy distribution functions of cathodic vacuum arcs: A study involving the plasma potential and biased plasmas

“…Focusing on the methods that can resolve charge and/or mass and provide information on distribution functions, one usually employs either (i) electrostatic field methods, [1][2][3][4] or (ii) time-of-flight (TOF) techniques. [5][6][7][8][9] There is considerable divergence in the published data. Generally, researchers using electrostatic methods came to the conclusion that the energy distribution functions, at least in part, depend on the charge state of the ion species under consideration, whereas TOF methods stated that the velocity distribution functions are independent of the charge state.…”