Dr. Amanda M. Lietz
Assistant Professor
Department of Nuclear Engineering
North Carolina State University

Abstract

Low-temperature plasmas (LTPs) are non-equilibrium systems where a small fraction of gas is ionized and electron temperatures are much greater than the neutral gas temperatures. LTPs can produce highly reactive chemical species, such as radicals and excited states, at gas temperatures much lower than they would be produced thermally. They also produce fluxes of energetic electrons, ions, and photons. LTPs are essential for many steps in the production of computer chips, and controlling the ion energies and reactive fluxes is critical for optimizing those processes. The neutral reactive species can influence cells in unique ways, making treatment of wounds and cancer possible.

Computational modeling is critical in this field, where the reactive species are important but have short lifetimes and are challenging to measure. Excitation, ionization, and dissociation create many species, often with hundreds or thousands of potential processes or pathways. Models can highlight important microscale processes (like photon emission from a particular transition) that control macroscopic processes (such as ionization wave speed). The talk will include a brief overview of computational modeling approaches for low-temperature plasmas, including global, fluid, hybrid, and particle methods. Several examples highlighting different types of modeling in several different applications will be discussed.

Biography

Dr. Amanda M. Lietz is an Assistant Professor in the Nuclear Engineering Department at North Carolina State University, and the leader of the Computational Plasma Science Group. Her group focuses on developing and using plasma simulation tools for low-temperature plasmas. Low-temperature plasmas are critical to many current and potential future technologies. Of particular interest to the group are semiconductor processing for computer chip production, biomedical treatments, and electrification of the chemical industry to reduce fossil fuel consumption. Dr. Lietz has a Ph.D. in Nuclear Engineering and Radiological Sciences from the University of Michigan and a B.S. in Nuclear, Plasma and Radiological Engineering from the University of Illinois at Urbana-Champaign. Before joining North Carolina State University, she was a postdoctoral appointee at Sandia National Laboratories in the Applied Optical and Plasma Sciences Department. She has been named an Emerging Leader by the Journal of Physics D: Applied Physics and received the Richard and Eleanor Towner Prize for Outstanding Ph.D. Research.

Thursday, October 27. 2022
4:00 pm seminar

Hybrid Option  (Speaker is in person)

zoom (link upon request)
or
Room 1202 Burlington Labs