Regenerative Soot: A cusp field, graphite hollow cathode, carbon cluster ion source

TL;DR

This paper presents a novel all-carbon hollow cathode ion source with a cusp magnetic field that facilitates carbon cluster synthesis, revealing two distinct discharge regions influencing soot formation and ionization processes.

Contribution

It introduces a specially designed cusp magnetic field in a carbon hollow cathode ion source, demonstrating its role in creating two discharge regions and enabling carbon cluster synthesis.

Findings

Cusp magnetic field establishes two discharge regions.

Soot formation is influenced by plasma dynamics.

Carbon clustering occurs on cathode walls.

Abstract

An all carbon hollow cathode ion source with a specially designed cusp magnetic field Bz as a function of radius and theta is described. Velocity spectra from this source has shown that carbon cluster synthesis is taking place as a function of the source design, discharge parameters and the state of sooting. The cusp magnetic field seems to establish two distinct discharge regions within the source. The first is a narrow annular ring that is 2 mm thick and 15-20 mm long with restricted axial and radial extent of the cusp field. Here the source gas ionizes. The carbon atoms sputter of the cathode walls and subsequently get ionized. The other one is a cylindrical plasma region with the entire axial range of Bz. In this region the dynamics of the soot formation from the plasma constituent on the cathode walls seems to be related to the carbon clustering processes