Engineering Research Building
1500 Engineering Drive
Madison, WI 53706
Ph: (608) 263-1547
Professor Schmitz’s research interests are aligned towards plasma physics in the edge of high temperature fusion energy plasmas and the intimate contact of such plasmas with material wall elements. This involves research on high density, low temperature plasma phenomena and suitable diagnostic techniques to investigate such plasmas.
Resonant coupling phenomena of small amplitude external control forces on strong guiding force fields are at the heart of Schmitz research. This principle is applied as an innovative technique for plasma edge control in almost all large scale magnetic confinement devices. Here, small amplitude resonant magnetic perturbation fields are applied onto the strong magnetic field of the confining magnetic cage to alter the edge magnetic field structure. A three-dimensional (3-D) plasma edge topology is induced. Schmitz key interest lay in the field of 3-D plasma edge transport and plasma wall interaction. These challenges apply to both lines of magnetic confinement concepts for magnetic confinement of high performance fusion plasmas - the Tokamak and the Stellarator.
Diagnosis of the effects of 3-D magnetic control fields requires enhanced diagnostic methods. Here, Schmitz particular interest is in the field of active spectroscopic methods to measure plasma parameters with non-invasive methods. Atomic physics is used to predict emission strengths of selected atomic emission lines. In turn, they can be used to reconstruct plasma parameters - given that appropriate atomic models are at hand. Development and deployment of such models and application in an integrated fashion with suited injection, observation and data acquisition system is a vital activity within Schmitz research interests. Exploration of the non-linear atomic processes requires access to easily adaptable plasma conditions. They are realized at UW Madison by means of helicon wave driven plasma test stands. Development of these helicon plasmas to high density at considerable electron and ion temperatures is an integrated part of the overall research goal in the group of Professor Schmitz.
The experimental work is embedded into an integrated approach to link the single point measurements in 3-D systems to a more general and complete outcome. Field line tracing coupled to models for magneto-hydrodynamic plasma response to the 3-D control fields are used to understand the edge magnetic topology. The 3-D fluid plasma and kinetic neutral transport code EMC3-Eirene is deployed to couple transport phenomena and dedicated plasma neutral interaction processes into the workflow. Extension and improvement of suited models describing the complex situation of high temperature plasma interacting with material surfaces is a key research interest of Professor Schmitz.