title: High-adiabat high-foot inertial confinement fusion implosion experiments on the national ignition facility.
abstract: This Letter reports on a series of high-adiabat implosions of cryogenic layered deuterium-tritium (DT) capsules indirectly driven by a "high-foot" laser drive pulse at the National Ignition Facility. High-foot implosions have high ablation velocities and large density gradient scale lengths and are more resistant to ablation-front Rayleigh-Taylor instability induced mixing of ablator material into the DT hot spot. Indeed, the observed hot spot mix in these implosions was low and the measured neutron yields were typically 50% (or higher) of the yields predicted by simulation. On one high performing shot (N130812), 1.7 MJ of laser energy at a peak power of 350 TW was used to obtain a peak hohlraum radiation temperature of ∼300  eV. The resulting experimental neutron yield was (2.4±0.05)×10(15) DT, the fuel ρR was (0.86±0.063)  g/cm2, and the measured Tion was (4.2±0.16)  keV, corresponding to 8 kJ of fusion yield, with ∼1/3 of the yield caused by self-heating of the fuel by α particles emitted in the initial reactions. The generalized Lawson criteria, an ignition metric, was 0.43 and the neutron yield was ∼70% of the value predicted by simulations that include α-particle self-heating.
authors.affiliation: Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551, USA.
authors.forename: H-S
authors.initials: HS
authors.lastname: Park
authors.affiliation: Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551, USA.
authors.forename: O A
authors.initials: OA
authors.lastname: Hurricane
authors.affiliation: Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Callahan
authors.affiliation: Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551, USA.
authors.forename: D T
authors.initials: DT
authors.lastname: Casey
authors.affiliation: Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551, USA.
authors.forename: E L
authors.initials: EL
authors.lastname: Dewald
authors.affiliation: Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551, USA.
authors.forename: T R
authors.initials: TR
authors.lastname: Dittrich
authors.affiliation: Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551, USA.
authors.forename: T
authors.initials: T
authors.lastname: Döppner
authors.affiliation: Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551, USA.
authors.forename: D E
authors.initials: DE
authors.lastname: Hinkel
authors.affiliation: Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551, USA.
authors.forename: L F
authors.initials: LF
authors.lastname: Berzak Hopkins
authors.affiliation: Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551, USA.
authors.forename: S
authors.initials: S
authors.lastname: Le Pape
authors.affiliation: Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551, USA.
authors.forename: T
authors.initials: T
authors.lastname: Ma
authors.affiliation: Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551, USA.
authors.forename: P K
authors.initials: PK
authors.lastname: Patel
authors.affiliation: Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551, USA.
authors.forename: B A
authors.initials: BA
authors.lastname: Remington
authors.affiliation: Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551, USA.
authors.forename: H F
authors.initials: HF
authors.lastname: Robey
authors.affiliation: Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Salmonson
authors.affiliation: Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Kline