[1] Univ Rochester, Laser Energet Lab, Rochester, NY 14623 USA
[2] Univ Rochester, Fus Sci Ctr, Rochester, NY 14623 USA
[3] Univ Rochester, Dept Mech Engn, Rochester, NY 14623 USA
[4] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA
[5] Univ London Imperial Coll Sci Technol & Med, Dept Phys, London SW7 2AZ, England
[6] Univ Rochester, Dept Phys, Rochester, NY 14623 USA