Experimental Observations of Laser-Driven Tin Ejecta Microjet Interactions*

The study of high-velocity particle-laden flow interactions has broad applicability to fields ranging from planetary formation [1] to cloud interactions [2]. Ejecta microjets are micron-scale jets formed by strong shocks interacting with imprinted surfaces to generate streams of particles traveling at more than several kilometers per second. As such, ejecta microjets offer a methodology to study particle interactions at extreme velocities. We present the first time-sequences of x-ray radiography images of two interacting tin ejecta microjets from experiments performed on the OMEGA EP laser [3]. We observe that jets emerging from a shock pressure of 11.7 GPa pass through each other unattenuated, whereas jets emerging from a shock pressure of 116.0 GPa have five times greater densities and interact strongly, forming a cloud around the center-point of interaction. Radiation hydrodynamics simulations of particle-stream collisions capture many of the observed interaction behavior characteristics, but are unable to capture the full spread of the cloud formed. 

 

[1] M. Lambrechts et al., A&A 627, A83 (2019).

[2] T. Matsumoto et al., The Astrophysical Journal 801, 77 (2015).

[3] A. M. Saunders et al., PRL 127, 155002 (2021).