Design and Characterization of a Theta Pinch Discharge for Atomic Emission Spectroscopy

The high temperature and density plasma generated by magnetic constriction of a preexisting plasma was studied as an emission source for the elemental analysis of solid materials. This high energy plasma has the ability to directly sample solid materials. A theta pinch discharge was designed and constructed to create this magnetically compressed plasma. In the theta pinch geometry, magnetic compression is achieved by a pulsed, high current discharge through a coil. The coil encloses an insulated discharge vessel containing an ionized plasma at low pressure. The field generated by the high current discharge through the coil causes magnetic compression of the plasma, increasing both the plasma temperature and density. The main discharge source which generates the high current pulse has been operated at peak voltages of -31 kV, and has been shown to be capable of generating peak discharge currents of 60 kA. Two coil geometries, cylindrical and helical, have been examined with this source. Improved coupling between the high current discharge and the plasma was observed with the higher inductance, helical coil. Along with the effect of coil geometry, the effect of fill gas on coupling efficiency was also studied. The theta pinch was operated with both argo and helium fill gases. Coupling between the main discharge and the plasma was more efficient for discharges in argon than for discharges in helium, most likely due to the higher ionization potential of helium.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Kamla, Gregory James

• Chemistry, Analytical

Identifier

(UMI)AAI8600228

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/70310