Alan Hoskinson

Research Assistant Professor

Department of Electrical and Computer Engineering Tufts University

Tuesday, April 28^th at 2:00 pm

WANG 1004

Control of high-frequency microplasmas for materials and optical applications

Using microwave power to generate plasmas at or near atmospheric pressure offers several advantages over comparable techniques: high steady-state electron densities, low voltage requirements, and extremely stable operation.  The development of "cold" atmospheric-pressure plasma sources promises to open up new applications in areas from materials processing to medicine to chemical analysis.  The high-energy electrons in the plasma can drive chemical reactions while the gas and substrate remain cool.

In this talk, I discuss techniques for manipulating such plasmas to achieve the desired properties.  The plasma structure can be altered by pulsing the microwave power, the electron density and plasma impedance can be adjusted by varying the drive frequency, and individual plasmas in an array can be switched on and off using solid-state circuitry.  The plasma properties in these systems are characterized by applying an array of spectroscopic and electrical techniques.  The high electron densities and stable operation make microwave-generated plasmas well-suited for applications requiring rapid generation of excited chemical species.  Here I present exploratory studies in two such areas: rapid deposition of diamond-like carbon films, and the integration of microwave plasmas into a rare-gas laser system.

Alan R. Hoskinson is a Research Assistant Professor with the Electrical and Computer Engineering Department at Tufts University.  He obtained the Ph. D. degree from the Engineering Physics Department at the University of Wisconsin-Madison in 2009, specializing in the physics of dielectric barrier discharge operation.  His research interests are in diagnostics and applications of "cold" plasmas, particularly when operating at atmospheric pressure.  Recent investigations have included studies of control of microplasmas using solid-state electronics, development of spectroscopic analysis techniques, and engineering discharge systems for use in film deposition, chemical generation, gas-phase lasers and other applications.