Schlieren diagnostic for cinematic visualization of dense plasma jets at Alfvénic timescales

Abstract

The manner in which magnetized plasma jets evolve remains key to better understanding the behavior of hydromagnetic systems and providing new insights into how they can be dynamically controlled. In this work, we present the underlying theory, apparatus, and optical features of a schlieren diagnostic capable of cinematically visualizing dense plasma jets. We identify the range of plasma density over which the diagnostic is sensitive and describe ways to further improve image contrast. This diagnostic features the unique ability to simultaneously resolve both the characteristic Alfvenic timescales and spatial flow features with continuous acquisition over the lifetime of a jet. We use this diagnostic to visualize the formation and evolution of hydromagnetic jets produced from a plasma gun device. Dynamic coherent flow features are identified and tracked over time throughout the evolutionary progression of plasma jets. Finally, the process by which these coherent features translate into perturbations of magnetized bow shocks is visualized.