Transport efficiency of vacuum arc plasma in a curved magnetic filter

Abstract

We describe two methods for increasing the transmission efficiency of vacuum arc plasma through curved magnetic filters. In the first method the substrate is connected to the anode or biased to a negative voltage. In the second method a metal grid is placed between the substrate and the exit of the magnetic filter, and biased to a positive voltage whereas the substrate is biased negatively. The ion saturation current and electron saturation current of the plasma between the filter exit and the substrate were measured using a current collector plate and a Langmuir probe, respectively, and the ion density estimated. For the experimental conditions of the work described here, the measured ion flux ͑ion saturation current͒ near the duct exit was increased by up to about 80% ͑from 140 to 250 mA͒, and the measured ion density was increased by up to about 40% ͑from 3.7ϫ 10 11 to 5.2 ϫ 10 11 cm −3 ͒. These results can be explained by the ambipolar influence of enhanced electron flow on the accompanying plasma ion component, leading also to enhanced ion flow.

Effect of Filtering Duct Coil Current on the Bonding Structure of Tetrahedral Amorphous Carbon Film

“…The average value of the ion flux is shown in Fig.7. Meanwhile in our experiment, there is not much difference in the average ion current between 200V and 500V substrate bias when the filtering duct coil current was fixed, this result is also corresponding to the results that are reported by YaWei Hu [12]. The increasing coil current will increase the magnetic field density in the duct, which will reduced plasma losses to the walls due to a reduction diffusion perpendicular to field lines [13,14].…”

Guiding the deposition flux in an ionized magnetron discharge

“…This is known as ambipolar diffusion. Similar arguments and observations are used to explain the plasma confinement in magnetically filtered arc discharges [16,17]. Thus, the motion of the ions, thermalized or not, is determined by the effect of the magnetic field on the electrons.…”

Phase-resolved profiles of electron energy deposition in inductively coupled radio-frequency plasmas driven under confronting divergent magnetic fields

“…For example, plasma confinement is utilized in fusion plasmas to keep them at a high density and away from the reactor walls, and magnetic filters are used to select specific species or to remove particles in plasma flow by its charge-to-mass ratio. [1][2][3][4][5][6][7][8] Recently, it was proposed to use the separatrix of confronting divergent magnetic fields (CDMFs, see Fig. 1) as a magnetic shutter 9) for an inductively coupled plasma (ICP).…”