Studying converging shock collisions in novel hybrid-drive shock ignition geometries

Abstract

GMXI-monochromatic, gated core imaging Henway-dopant spectral emission NBT-neutron bang time NTOF-neutron yield, ion temperature Dante-hohlraum temperature NTD-reaction rate history, bang time FABS (B25 and B30)-backscatter from hohlraum drive beams TIM-based diagnostics: SXR-soft x-ray imaging through hohlraum LEH XRFC-emission imaging of imploding capsule LFC-emission imaging of imploding capsule (different view) SSCA-streaked emission from imploding core LAPC-emission of beam spots on thin-walled hohlraum No special equipment needs are required for these experiments. Laser Configuration These experiments will use all 60 beams from OMEGA. The beams are grouped in terms of hohlraum drive and direct drive beams, which have a total of 48 and 12 beams, respectively. All beams point through Laser Entrance Holes (6 total), which are distributed around the spherical hohlraum with 4-fold symmetry (1 LEH for each face of a cube). LEH1 is located at θ = 90°, φ = 36°, LEH2 is located at θ = 90°, φ =-144°, and so on. Each LEH has 8 hohlraum drive beams that are arranged to irradiate the hohlraum walls while missing the capsule and opposite side LEHs. Each LEH also has 2 direct drive beams that enter the LEH at a 10° angle to the LEH normal and directly illuminate the capsule. No phase plates are used for either group of beams. The ignitor beams are defocused to give roughly a 300 μm spot on the capsule, however, we expect to be able to adjust this on shot day to give either greater intensity or better beam symmetry. We will only have a single driver available for all beams and will use either the SS1707SV001 or SS1904SV001 pulse shapes. Max energy will be requested for all beams. The original hohlraum target design used circular LEHs, however, we are also studying the benefits of elliptical LEHs (see Fig. 10), as we believe they will relax our misalignment and beam pointing tolerance. Hohlraums may also require a small hole aligned to the Target Viewing System in order to ensure proper centering of the capsule during the shot.