Point-Source Helicity Injection Current Drive System for the Pegasus Toroidal Experiment
Recent Pegasus experiments are developing solenoid-free startup techniques using point-source magnetic helicity injection. These plasma sources, called “plasma guns”, ionize a stream of gas in a discharge channel, and bias this channel with respect to an external electrode, driving current along the plasma stream, which relaxes into a tokamak-like equilibrium. The relaxed discharges formed by these injectors exhibit high current amplification, which is the ratio of total toroidal current to the gun-driven current. The development and present design of these injectors are described, and time traces from a typical discharge are presented.
KeywordsMagnetic confinement Tokamak Helicity injection
- 5.A.J. Redd et al., J. Fusion Energy 27, 100 (2008); T.R. Jarboe, Fusion Technol. 36, 85 (1999)Google Scholar
- 14.N. Eidietis, PhD dissertation, Department of Engineering Physics, University of Wisconsin, Madison, Wisconsin, USA (2007)Google Scholar
- 15.D.J. Battaglia, M.W. Bongard, R.J. Fonck, A.J. Redd, A.C. Sontag, Formation of a tokamak-like plasma in initial experiments using an outboard plasma gun current source. J. Fusion Energy (in press). doi:10.1007/s10894-008-9165-y