title: Effect of target material on fast-electron transport and resistive collimation.
abstract: The effect of target material on fast-electron transport is investigated using a high-intensity (0.7 ps, 10(20)  W/cm2) laser pulse irradiated on multilayered solid Al targets with embedded transport (Au, Mo, Al) and tracer (Cu) layers, backed with millimeter-thick carbon foils to minimize refluxing. We consistently observed a more collimated electron beam (36% average reduction in fast-electron induced Cu Kα spot size) using a high- or mid-Z (Au or Mo) layer compared to Al. All targets showed a similar electron flux level in the central spot of the beam. Two-dimensional collisional particle-in-cell simulations showed formation of strong self-generated resistive magnetic fields in targets with a high-Z transport layer that suppressed the fast-electron beam divergence; the consequent magnetic channels guided the fast electrons to a smaller spot, in good agreement with experiments. These findings indicate that fast-electron transport can be controlled by self-generated resistive magnetic fields and may have important implications to fast ignition.
authors: Center for Energy Research, University of California, San Diego, La Jolla, California 92093, USA.
authors: S
authors: S
authors: Chawla
authors: M S
authors: MS
authors: Wei
authors: R
authors: R
authors: Mishra
authors: K U
authors: KU
authors: Akli
authors: C D
authors: CD
authors: Chen
authors: H S
authors: HS
authors: McLean
authors: A
authors: A
authors: Morace
authors: P K
authors: PK
authors: Patel
authors: H
authors: H
authors: Sawada
authors: Y
authors: Y
authors: Sentoku
authors: R B
authors: RB
authors: Stephens
authors: F N
authors: FN
authors: Beg