312 / 2019-01-24 15:39:21

Experimental investigation of Richtmyer-Meshkov instability in convergent interface between solid tin and foamed polystyrene

Richtmyer-Meshkov instability,pulsed power,convergent shock wave

全体主题 > Interface Instabilities at Extremes

The Richtmyer-Meshkov instability (RMI) describes the behavior of a perturbed interface separating two materials of different densities when processed by a shock wave. Understanding the characteristics of this phenomenon is of great importance in a wide range of scientific and engineering applications among which the instability encountered in inertial confinement fusion (ICF) is of great interest [Dittrich et al. 1994; Clark et al. 2011]. The instability phenomena have been thoroughly studied for perfect fluid and gases using shock tube facility most of which providing planner shock waves. However, the imploding of the ICF capsule is in convergent geometry which could not be investigated by the planner shock wave. Recently, some researchers are working hard to generate convergent shock wave in shock tubes [Biamino et al. 2015; Luo et al. 2015]. In this report, an alternative way to generate cylinder shock wave in solid materials will be present.
The imploding process of the ICF first experience an acceleration phase after the shock wave incidence and finally become deceleration phase after shock wave reflection from the core[Lobatchev and Betti 2000]. In our experiment, the tin target was filled with foamed polystyrene to generate deceleration process.
The cylinder shock wave in our experiment was generated by the impacting of a magnetic driven liner onto the tin target. About 2 MA current was delivered to a 0.5mm thick aluminum liner by a pulsed power facility, then the liner will implode driven by the Lorentz force. This method show great advantage for high symmetry of the loading by magnetic field compression.