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. An emerging and very actively pursued field of research is high-density plasma generation by helicon waves in the whistler regime. This method of plasma generation is of great promise for next generation, plasma-based wakefield accelerators.
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. In the fusion branch of his research, he and students work on the forefront of 3D edge physics and 3D divertor questions in both tokamaks and stellarators. In tokamaks, 3D edge research questions are related in particular to the application of resonant magnetic perturbation fields, which break the toroidal axisymmetry of the tokamak device and necessitate a full 3D treatment. In stellarators, the 3D nature of plasma edge and divertor physics is inherent to the twisted device concept, and researchers in Schmitz-s group deploy the most modern, state of the art 3D plasma edge fluid and kinetic neutral transport code EMC3-EIRENE.
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 the considerable electron and ion temperatures is an integrated part of the overall research goal in the group of Professor Schmitz. As an associate member of the AWAKE project at CERN, he and his group is working on the development of reliable, and remotely operable plasma diagnostics based on spectroscopy to diagnose the high level of axial density homogeneity needed in this new accelerator concept.
Professor Schmitz has conceptualized in the past two years a number of outreach activities. The declared goal of these programs in the K-12 education arena is to bring Plasmas as a widely relevant state of matter to students of the entire basic education program. This includes regular visits to Elementary Schools in and around Madison. The "Plasma Show" developed for this purpose takes the kids on a journey from basic plasma phenomenon and appearances to the basics of electrostatics and hands-on experiments on a giant Plasma Ball. Students learn about light emission from plasmas and how it is generated to magnetic fields used to contain plasmas. Prof. Schmitz also offers a "Research Experience" for high-school students and teachers and a one-week "Plasma Academy", in which a group of high-school students and teachers develops teaching modules for the Advanced Placing Physics curriculum in the state of Wisconsin. It is planned to continue the summer internship in a weekly internship project for high-school students starting in fall 2018.