| Plasma Physics |
|---|
| Space Plasmas |
| Laboratory Space Plasmas |
| Fusion Plasmas |
| Electron Temperature Fluctuations |
| Chaos and Nonlinear Dynamics |
|---|
| Nonlinear Optics |
| Chaos in Fusion Plasmas |
| Publications |
|---|
Research Summary
Plasma Physics
My current research focuses on terrestrial based laboratory studies of the Sun's atmosphere (chromosphere & corona), and Earth’s magnetosphere and aurora. In these investigations we study the basic plasma physics microprocesses that underlie the observed macroscopic phenomena. Such laboratory studies cannot hope to “simulate” astrophysical phenomena – the parameter regimes are far too disparate. Rather, the goal is to study similar phenomena in the laboratory to benchmark theoretical models, which can then be applied with more confidence to the astrophysical phenomena of interest. This type of work is invaluable in understanding the link between the plasma micro and macro-scale processes, in that such detailed measurements are impossible to obtain via either satellite or telescope. Our current studies concentrate on Alfvén waves, which propagate along field lines like waves on a plucked string. These processes are thought important in a wide range of astrophysical phenomena, especially in the formation and heating of the Sun's corona, Earth’s aurora and the interaction of the solar wind and Earth’s magnetosphere.
In collaboration with the University of Texas and MIT, we have installed an ECE system on the C-Mod tokamak to measure the electron temperature fluctuations on fusion devices. This work is a continuation of work i did as a post doc at the Fusion Research Center working on the TEXT-U tokamak. We (Pepi Cima and I) applied correlation techniques to analyze microwave emission (ECE) from fusion plasmas, which led to the first measurement of the turbulent electron temperature fluctuations in the core of a tokamak plasma. The measurement is a significant step toward understanding electron heating and electrostatic turbulence with their consequent role in plasma “anomalous” transport. This work continued as a guest scientist at the Max-Planck-Institut for Plasma Physics in Germany, where comparisons between stellarator and tokamak plasmas were made.
Chaos & Nonlinear Dynamics
After leaving the Peace Crops, I moved to Germany. My work at the German Flight Research Institute (DLR – Deutsche Forschungsanstalt für Luft- und Raumfahrt) was concerned with basic research in nonlinear optics and the development of optical sensors. Our investigations concentrated on the suppression of chaos to find stable operating regimes for simple fiber-optic systems.
My graduate work at the University of Wisconsin encompassed several topics in plasma physics, incorporating experimental work on both small and large fusion facilities, numerical simulation and data analysis. My dissertation research endeavored to characterize the global dynamics of pulsed plasmas using chaos theory. Though I don't at present spend much time on this research topic, I do continue to dabble in it, looking for chaos in chemical reactions, the melting of metals, and in dusty plasma quasi crystals.