1. Oak Ridge Associated Universities, Oak Ridge, Tennessee 37830, USA
2. General Atomics, San Diego, California 92186-5608, USA
3. Massachusetts Institute of Technology, Boston, Michigan 02139, USA
4. Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA
5. Lawrence Livermore National Laboratory, Berkeley, California 94720, USA
6. University of California San Diego, San Diego, California 92093, USA