Observation of Single-Mode, Kelvin-Helmholtz Instability in a Supersonic Flow

• Published in: Physical review letters Vol. 115; no. 14; p. 145001
• Main Authors: Wan, W C, Malamud, G, Shimony, A, Di Stefano, C A, Trantham, M R, Klein, S R, Shvarts, D, Kuranz, C C, Drake, R P
• Format: Journal Article
• Language: English
• Published: United States American Physical Society (APS) 01-10-2015
• Subjects: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; compressible; Evolution; Fluid dynamics; hydrodynamic instabilities; Initial conditions; Kelvin-Helmholtz instability; Plasmas; Radiography; Shear layers; supersonic; Supersonic flow
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.115.145001

We report the first observation, in a supersonic flow, of the evolution of the Kelvin-Helmholtz instability from a single-mode initial condition. To obtain these data, we used a novel experimental system to produce a steady shock wave of unprecedented duration in a laser-driven experiment. The shocked, flowing material creates a shear layer between two plasmas at high energy density. We measured the resulting interface structure using radiography. Hydrodynamic simulations reproduce the large-scale structures very well and the medium-scale structures fairly well, and imply that we observed the expected reduction in growth rate for supersonic shear flow.