Dr. Levesque’s research centers around measurement and control of kink and tearing instabilities in tokamak plasmas. When these instabilities are not controlled, abrupt termination of the plasma (known as a "disruption") may result and cause physical damage to the fusion device. The control or prevention of magnetohydrodynamic (MHD) instabilities is essential for future tokamaks to become economical fusion power plants. Levesque focuses on developing advanced feedback control methods that are appropriate for a fusion reactor environment, including the use of magnetic, optical, and current-driving detectors and actuators. He also studies the physics of 3D scrape-off layer currents flowing between the helical plasma edge and surrounding walls.
Levesque’s research group utilizes the High Beta Tokamak – Extended Pulse (HBT-EP) facility on campus at Columbia to conduct experiments. This facility has a variable wall geometry, allowing detailed adjustments of 3D material boundaries while plasma conditions remain fixed. Within the HBT-EP group, Levesque oversees activities of the graduate students, guides experimental operations, and establishes research directions. He instructs students about maintaining and operating the tokamak, and assists in designing and implementing device upgrades.
Levesque began as a graduate student in Columbia’s Applied Physics and Applied Mathematics Department in 2006, and was awarded a 3-year Fusion Energy Sciences Fellowship for graduate study in 2007. He was instrumental in the design, construction, and installation of the present HBT-EP stabilizing wall and magnetic diagnostic/control sets that were installed during his graduate career. For his doctoral thesis research, Levesque detailed the interaction between dominant and secondary external kink instabilities in HBT-EP. This is applicable to fusion-grade tokamak plasmas, where multimode effects are important for plasma stability, especially during active magnetic feedback. Levesque earned a B.S. in physics from Rensselaer Polytechnic Institute in 2006, and a Ph.D. from Columbia in 2012. After receiving his Ph.D., Levesque stayed at Columbia as the lead scientist in the HBT-EP group. He has also collaborated with groups at the National Spherical Torus Experiment (NSTX), and is an Expert within the International Tokamak Physics Activity (ITPA) topical group on MHD, Disruptions, and Control, where he contributes to meetings and global research objectives.