Supersonic metal plasma impact on a surface: an optical investigation of the pre-surface region

Publication Type

Journal Article

Date Published

04/2010

LBNL Report Number

LBNL-2982E

Abstract

Aluminum plasma, produced in high vacuum by a pulsed, filtered cathodic arc plasma source, was directed onto a wall where if formed a coating. The accompanying "optical flare" known from the literature was visually observed, photographed, and spectroscopically investigated with appropriately high temporal (1 μs) and spatial (100 μm) resolution. Consistent with other observations using different techniques, it was found that the impact of the fully ionized plasma produces metal neutrals as well as desorbed gases, both of which interact with the incoming plasma. Most effectively are charge exchange collisions between doubly charged aluminum and neutral aluminum, which lead to a reduction of the flow of doubly charged before they reach the wall, and a reduction of neutrals as the move away from the surface. Those plasma-wall interactions are relevant for coating processes as well as for interpreting the plasma properties such as ion charge state distributions.

Journal

Journal of Physics D: Applied Physics

Volume

43

Year of Publication

2010

Short Title

J. Phys. D: Appl. Phys.

Issue

13
135201