Plasma source design constitutes a major research direction at PPL.
Typically an applied process, new sources are designed to meet specific treatment objectives. Techniques that are commonly applied range from simple direct current sources and radio-frequency capacitively coupled sources, to more complex dual sources, alternating current, and pulsed arc sources. Miniaturization, which presents a significant source of difficulty, is also a focus at PPL, with several successful miniature radio-frequency sources having been produced during recent years.
Radio frequency (RF) plasma sources, which make up a large part of the new sources designed at PPL, are typically used for generation of radicals and desired reactant species. The advantage of using RF lies in the option of removing the electrodes from the reaction chamber, allowing much longer electrode life and a wider range of plasma gases. DC sources are used to study electrode degradation or to produce pulsed arcs for nanoparticle studies. Material selection for these designs is tailored to the type of nanoparticles desired, granting the versatility to produce a wide variety of nanoparticles, including composites and oxides.
Incorporation of carbon nanotubes (CNTs) into plasma sources presents a novel approach pioneered at PPL. Although field-emission sources have been demonstrated, work at PPL is heading in the direction of thermo-field applications of CNT emitter arrays, which has promise to lead to new approaches to fluorescent lighting and a better understanding of the interaction of carbon nanostructures and the often highly aggressive environments of glow discharges.
Fundamental study of oxygen plasma-carbon nanotube interactions
Student: Leron Vandsburger
Investigator: Dr. Sylvain Coulombe,Dr. Jean-Luc Meunier.
Electrical and optical emission characterization of an atmospheric pressure arc
Student: Marie-Ève Gosselin.
Investigator: Dr. Sylvain Coulombe.