title: Seeding magnetic fields for laser-driven flux compression in high-energy-density plasmas.
abstract: A compact, self-contained magnetic-seed-field generator (5 to 16 T) is the enabling technology for a novel laser-driven flux-compression scheme in laser-driven targets. A magnetized target is directly irradiated by a kilojoule or megajoule laser to compress the preseeded magnetic field to thousands of teslas. A fast (300 ns), 80 kA current pulse delivered by a portable pulsed-power system is discharged into a low-mass coil that surrounds the laser target. A >15 T target field has been demonstrated using a <100 J capacitor bank, a laser-triggered switch, and a low-impedance (<1 Omega) strip line. The device has been integrated into a series of magnetic-flux-compression experiments on the 60 beam, 30 kJ OMEGA laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. The initial application is a novel magneto-inertial fusion approach [O. V. Gotchev et al., J. Fusion Energy 27, 25 (2008)] to inertial confinement fusion (ICF), where the amplified magnetic field can inhibit thermal conduction losses from the hot spot of a compressed target. This can lead to the ignition of massive shells imploded with low velocity-a way of reaching higher gains than is possible with conventional ICF.
authors.affiliation: Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA.
authors.forename: O V
authors.initials: OV
authors.lastname: Gotchev
authors.forename: J P
authors.initials: JP
authors.lastname: Knauer
authors.forename: P Y
authors.initials: PY
authors.lastname: Chang
authors.forename: N W
authors.initials: NW
authors.lastname: Jang
authors.forename: M J
authors.initials: MJ
authors.lastname: Shoup
authors.forename: D D
authors.initials: DD
authors.lastname: Meyerhofer
authors.forename: R
authors.initials: R
authors.lastname: Betti