[1] Univ Calif Irvine, Irvine, CA 92697 USA
[2] Gen Atom, San Diego, CA USA
[3] Univ Texas Austin, Austin, TX USA
[4] Oak Ridge Natl Lab, Oak Ridge, TN USA
[5] Rokkasho Fus Inst, Natl Inst Quantum & Radiol Sci & Technol, Aomori 0393212, Japan
[6] Univ Calif Los Angeles, Los Angeles, CA USA
[7] Max Planck Inst Plasma Phys, Boltzmannstr 2, D-85748 Garching, Germany
[8] Univ Wisconsin, Madison, WI USA