AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Light Scattering Studies of Single Particle Optically Induced Plasma Explosions
CHRIS SORENSEN, Jeff Powell, Kansas State University
Abstract Number: 500 Working Group: Single Aerosol Particle Studies - Fundamentals
Abstract Understanding the ultrafast formation, excitation, and relaxation of dense plasmas generated from single nanoparticles (NPs) under intense light is of fundamental importance. We present initial studies of ultrafast plasma formation and density evolution during plasma expansion of 100 nm SiO$_2 NPs. The experiments were performed at SLAC Linac Coherent Light Source (LCLS) in Stanford. The NPs were aerosolized from aqueous suspension, dried and focused with an aerodynamic lens into the target area. An intense, 800 nm, femtosecond pump laser ionized single NPs. The transient structure of the resulting plasma was determined by elastic scattering of a subsequent intense, ultrashort, 1.5 nm, X-ray probe pulse at delay times in the range of 0 to 200 femtoseconds. This allowed for tracing the spatiotemporal plasma density dynamics. Analysis of the scattered “light” involved using Mie scattering theory and Q-space analysis. The plasma structure showed prolate symmetries with fuzzy boundaries that evolved over femtosecond time scales.