title: Ion acceleration from the shock front induced by hole boring in ultraintense laser-plasma interactions.
abstract: Ion-acceleration processes have been studied in ultraintense laser plasma interactions for normal incidence irradiation of solid deuterated targets via neutron spectroscopy. The experimental neutron spectra strongly suggest that the ions are preferentially accelerated radially, rather than into the bulk of the material from three-dimensional Monte Carlo fitting of the neutron spectra. Although the laser system has a 10(-7) contrast ratio, a two-dimensional magnetic hydrodynamics simulation shows that the laser pedestal generates a 10 mum scale length in the coronal plasma with a 3 mum scale-length plasma near the critical density. Two-dimensional particle-in-cell simulations, incorporating this realistic density profile, indicate that the acceleration of the ions is caused by a collisionless shock formation. This has implications for modeling energy transport in solid density plasmas as well as cone-focused fast ignition using the next generation PW lasers currently under construction.
authors.affiliation: Central Laser Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, United Kingdom.
authors.forename: H
authors.initials: H
authors.lastname: Habara
authors.forename: K L
authors.initials: KL
authors.lastname: Lancaster
authors.forename: S
authors.initials: S
authors.lastname: Karsch
authors.forename: C D
authors.initials: CD
authors.lastname: Murphy
authors.forename: P A
authors.initials: PA
authors.lastname: Norreys
authors.forename: R G
authors.initials: RG
authors.lastname: Evans
authors.forename: M
authors.initials: M
authors.lastname: Borghesi
authors.forename: L
authors.initials: L
authors.lastname: Romagnani
authors.forename: M
authors.initials: M
authors.lastname: Zepf
authors.forename: T
authors.initials: T
authors.lastname: Norimatsu
authors.forename: Y
authors.initials: Y
authors.lastname: Toyama
authors.forename: R
authors.initials: R
authors.lastname: Kodama
authors.forename: J A
authors.initials: JA
authors.lastname: King
authors.forename: R
authors.initials: R
authors.lastname: Snavely
authors.forename: K
authors.initials: K
authors.lastname: Akli
authors.forename: B
authors.initials: B
authors.lastname: Zhang
authors.forename: R
authors.initials: R
authors.lastname: Freeman
authors.forename: S
authors.initials: S
authors.lastname: Hatchett
authors.forename: A J
authors.initials: AJ
authors.lastname: MacKinnon
authors.forename: P
authors.initials: P
authors.lastname: Patel
authors.forename: M H
authors.initials: MH
authors.lastname: Key
authors.forename: C
authors.initials: C
authors.lastname: Stoeckl
authors.forename: R B
authors.initials: RB
authors.lastname: Stephens
authors.forename: R A
authors.initials: RA
authors.lastname: Fonseca
authors.forename: L O
authors.initials: LO
authors.lastname: Silva