title: Focusing of relativistic electrons in dense plasma using a resistivity-gradient-generated magnetic switchyard.
abstract: A method for producing a self-generated magnetic focussing structure for a beam of laser-generated relativistic electrons using a complex array of resistivity gradients is proposed and demonstrated using numerical simulations. The array of resistivity gradients is created by using a target consisting of alternating layers of different Z material. This new scheme is capable of effectively focussing the fast electrons even when the source is highly divergent. The application of this technique to cone-guided fast ignition inertial confinement fusion is considered, and it is shown that it may be possible to deposit over 25% of the fast electron energy into a hot spot even when the fast electron divergence angle is very large (e.g., 70° half-angle).
authors.affiliation: Central Laser Facility, Rutherford-Appleton Laboratory, Chilton, Oxon., OX11 0QX, United Kingdom.
authors.forename: A P L
authors.initials: AP
authors.lastname: Robinson
authors.forename: M H
authors.initials: MH
authors.lastname: Key
authors.forename: M
authors.initials: M
authors.lastname: Tabak