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341 Engineering Research Building
1500 Engineering Drive
Madison, WI 53706

Ph: (608) 263-7799
Fax: (608) 265-2364
rjfonck@wisc.edu

Profile Summary

Professor Fonck is an experimental physicist with research interests in plasma and fusion science, atomic processes in high-temperature plasmas, and diagnostic instrumentation. His main research focus is on the properties of magnetically confined plasmas for thermonuclear fusion energy applications.

He has developed a variety of diagnostic techniques for measuring the particle and energy content and the stability of very-high-temperature plasmas. Current applications focus on studies of density and energy microturbulence in hot plasmas to determine the basic source of anomalous plasma particle and energy losses. This includes studies of spatial and temporal correlations between fluctuating modes, plus nonlinear coupling between turbulent modes in the plasma. Most of these turbulence experiments are performed on national tokamak experimental facilities, such as the DIII-D tokamak device. The diagnostic hardware is usually developed and tested at UW-Madison, then moved to these facilities. Real-time interactions with the experiments and operation of the diagnostics are often pursued though internet-based remote connections between UW and the host site. Related interests include developing state-of-the-art, high-speed photon detection techniques and atomic physics in high-temperature plasmas, including observations and analysis technique developments.

Fonck is also pursuing the experimental study of a family of plasma magnetic confinement devices called low-aspect ratio tori. This very-nearly-spherical toroidal geometry allows the study of very high plasma pressures in a tokamak-like geometry. Plasma pressure limits under magnetic confinement are of interest as a basic physics topic, and have practical implications for the economic attractiveness of future fusion reactors. These studies started at UW-Madison with the small MEDUSA experiment, and are now concentrated in the Pegasus Toroidal Experiment program. The Pegasus project uses uniques high-stress magnet technology to access plasmas with near-unity aspect ratio, which in turn allows ready access to relatively high pressure plasma conditions. The focus of the program is on the current and pressure stability limits in this low-aspect regime. Additional areas of interest in the Pegasus program include: the use of plasma current injectors to initiate high temperature plasmas without the need for a strong solenoidal induction magnet; studies of radiofrequency waves and their interactions with confined plasmas to heat and sustain the plasma; and unique diagnostic measurements for these low-field and relatively high-density plasma conditions.

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