Performance of indirectly driven capsule implosions on NIF using adiabat-shaping. (May 2016)

• Record Type: Journal Article
• Authors: Robey, H F; Smalyuk, V A; Milovich, J L; Döppner, T; Casey, D T; Baker, K L; Peterson, J L; Bachmann, B; Hopkins, L F Berzak; Bond, E; Caggiano, J A; Callahan, D A; Celliers, P M; Cerjan, C; Clark, D S; Dixit, S N; Edwards, M J; Gharibyan, N; Haan, S W; Hammel, B A; Hamza, A V; Hatarik, R; Hurricane, O A; Jancaitis, K S; Jones, O S; Kerbel, G D; Kroll, J J; Lafortune, K N; Landen, O L; Ma, T; Marinak, M M; MacGowan, B J; MacPhee, A G; Pak, A; Patel, M; Patel, P K; Perkins, L J; Sayre, D B; Sepke, S M; Spears, B K; Tommasini, R; Weber, C R; Widmayer, C C; Yeamans, C; Giraldez, E; Hoover, D; Nikroo, A; Hohenberger, M; Johnson, M Gatu;
• Is Part Of: Journal of physics. Volume 717(2016)
• Publication Date: 2016-05
• Subjects: Physics -- Congresses; 530.5
• DOI: 10.1088/1742-6596/717/1/012045
• Languages: English
• ISSNs: 1742-6588

Abstract

Abstract: A series of indirectly driven capsule implosions has been performed on the National Ignition Facility to assess the relative contributions of ablation-front instability growth vs. fuel compression on implosion performance. Laser pulse shapes for both low and high-foot pulses were modified to vary ablation-front growth & fuel adiabat, separately and controllably. Two principal conclusions are drawn from this study: 1) It is shown that an increase in laser picket energy reduces ablation-front instability growth in low-foot implosions resulting in a substantial (3-10X) increase in neutron yield with no loss of fuel compression. 2.) It is shown that a decrease in laser trough power reduces the fuel adiabat in high-foot implosions results in a significant (36%) increase in fuel compression together with no reduction in neutron yield. These results taken collectively bridge the space between the higher compression low-foot results and the higher yield high-foot results.