[1] Los Alamos Natl Lab, Subat Phys Grp P 25, Los Alamos, NM 87545 USA
[2] MIT, Plasma Sci & Fus Ctr, 77 Massachusetts Ave, Cambridge, MA 02139 USA
[3] Lawrence Livermore Natl Lab, Design Phys Div, Livermore, CA 94550 USA
[4] Gen Atom, DIII D Plasma Control Grp, San Diego, CA 92186 USA