1. Department of Applied Physics and Applied Mathematics, Columbia University, 500 W. 120th Street, New York, New York 10027, USA
2. Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544, USA
3. Tibbar Plasma Technologies Inc., 274 DP Rd., Los Alamos, New Mexico 87544, USA
4. Department of Physics, Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712, USA