Mass separation of a multi-component plasma flow travelling through a magnetic transport system

Abstract

The travel of plasma flow produced by a dc arc through a transport system based on a curved magnetic field was studied. The characteristics of the system were the absence of a curved metallic plasma guiding duct ('open architecture') and the fact that the magnetic field coils were non-coaxial to the plasma flow. By means of Langmuir probe measurements it was shown that both shape and position of the cathode plasma flow at the exit of the transport system were governed by variation of currents of the magnetic coils as well as by biasing of a special electrode inserted into the plasma flow. It was found that with parameters of the transport system held constant, the plasma ions with lower m/Z were deflected more, e.g. Al ions were deflected more than Ti ions. For an arc with a composite cathode, consisting of mainly Cr-Fe-Ni, the profile of atoms of these elements at the exit of the transport system was measured by x-ray fluorescence spectrometry. The results obtained were consistent with the probe measurements, hence the transport system, in principle, may be used for spatial separation of a multi-component (in masses) plasma flow.

Charge state, angular distribution, and kinetic energy of ions from multicomponent-cathodes in vacuum arc devices

“…The vacuum-arc-produced metal plasma is used, for example, in vacuum arc ion sources (sometimes called Mevva ion sources, for metal vapor vacuum arc) 9,10 to form intense, energetic metal ion beams for ion implantation [11][12][13] and for particle accelerator injection, [14][15][16] in plasma generators for coating deposition, [17][18][19] and in high-current switches. 20,21 Interest in the plasma produced by vacuum arcs utilizing composite cathodes made of two or more different materials follows from the option of then generating multi-component ion beams for concurrent multi-element ion implantation, 22 the formation of composite metal coatings by vacuum arc deposition, [23][24][25][26][27][28] and from the use in vacuum arc switches of multicomponent cathodes 29 providing high mechanical strength and electrical conductivity while sustaining low ion erosion and contact weldability (materials often used in such switch electrodes are binary alloys like copper-bismuth, copper-antimony, and copper-beryllium. 30 ) Research in the plasma physics of vacuum arcs with multicomponent cathodes is thus of both fundamental 31 …”

Ion Charge Separation in a Multi‐Species Plasma Flowing through a Magnetic Transport System

“…The setup design was described in more detail elsewhere [12,13] and it was outlined briefly here. The setup design was described in more detail elsewhere [12,13] and it was outlined briefly here.…”

Charge separation of plasma flow in curvilinear magnetic field

“…The setup design has been described in much detail elsewhere [2,3] and is only briefly outlined here. A steady state discharge with a current of 50 A was initi ated at the front edge surface of water cooled cath ode 1 with a working surface diameter of 40 mm (see the inset to Fig.…”

“…Ring anode 2 with an inner diam eter of 60 mm was connected to a vacuum chamber that was evacuated to a residual pressure not exceeding 2 × 10 -3 Pa. It was previously demonstrated [2,3] that a metal plasma jet generated on the cathode surface passes via the anode hole and moves along the lines of a magnetic flux tube originating from the working cathode surface. The magnetic field was generated by five solenoids, three of which (3)(4)(5) were coaxial and the axis of other two (6) was perpendicular to that of the first three.…”

“…It was previously demonstrated [2,3] that a metal plasma jet generated on the cathode surface passes via the anode hole and moves along the lines of a magnetic flux tube originating from the working cathode surface. The magnetic field was generated by five solenoids, three of which (3)(4)(5) were coaxial and the axis of other two (6) was perpendicular to that of the first three. Solenoids 6 carried equal currents but were switched in the opposite directions, so as to pro duce additional, independently controlled deviation of the cathode jet in the working chamber.…”