Time evolution and asymmetry of a laser produced blast wave

E R Tubman,J Meinecke,N C Woolsey,P Tzeferacos,R A B Alraddadi,R H H Scott,H Ahmed,M Borghesi,R Crowston,J E Cross,B Reville,R Bolis,D Lamb,G Gregori,H W Doyle,D Doria,A P L Robinson

doi:10.1063/1.4987038

Abstract

Studies of a blast wave produced from carbon rods and plastic spheres in an argon background gas have been conducted using the Vulcan laser at the Rutherford Appleton Laboratory. A laser of 1500 J was focused onto these targets, and rear-side observations of an emission front were recorded using a fast-framing camera. The emission front is asymmetrical in shape and tends to a more symmetrical shape as it progresses due to the production of a second shock wave later in time, which pushes out the front of the blast wave. Plastic spheres produce faster blast waves, and the breakthrough of the second shock is visible before the shock stalls. The results are presented to demonstrate this trend, and similar evolution dynamics of experimental and simulation data from the FLASH radiation-hydrodynamics code are observed.

Highlights

When the sudden point release of energy into a homogeneous medium creates a pressure driven supersonic shock wave, it propagates out into the surrounding medium in ideal conditions.1 A physical system can be approximated by this model when the temporal and spatial scales are large compared to those associated with the energy release and the piston mass is negligible compared to the shocked mass.2 Such shock waves, known as blast waves, are common in astrophysics, and blast wave dynamics are used to predict supernova remnant evolution.3,4 These disturbances and associated shocks are readily created with high energy, intense lasers, enabling a detailed laboratory study of astrophysical relevant topics such as shock driven radiative instabilities,5 secondary shock formation,6 and the seeding7 and amplification8 of galactic magnetic fields
Studies of a blast wave produced from carbon rods and plastic spheres in an argon background gas have been conducted using the Vulcan laser at the Rutherford Appleton Laboratory
The emission front is asymmetrical in shape and tends to a more symmetrical shape as it progresses due to the production of a second shock wave later in time, which pushes out the front of the blast wave

Summary

INTRODUCTION

When the sudden point release of energy into a homogeneous medium creates a pressure driven supersonic shock wave, it propagates out into the surrounding medium in ideal conditions. A physical system can be approximated by this model when the temporal and spatial scales are large compared to those associated with the energy release and the piston mass is negligible compared to the shocked mass. Such shock waves, known as blast waves, are common in astrophysics, and blast wave dynamics are used to predict supernova remnant evolution. These disturbances and associated shocks are readily created with high energy, intense lasers, enabling a detailed laboratory study of astrophysical relevant topics such as shock driven radiative instabilities, secondary shock formation, and the seeding and amplification of galactic magnetic fields. A physical system can be approximated by this model when the temporal and spatial scales are large compared to those associated with the energy release and the piston mass is negligible compared to the shocked mass.2 Such shock waves, known as blast waves, are common in astrophysics, and blast wave dynamics are used to predict supernova remnant evolution.. Known as blast waves, are common in astrophysics, and blast wave dynamics are used to predict supernova remnant evolution.3,4 These disturbances and associated shocks are readily created with high energy, intense lasers, enabling a detailed laboratory study of astrophysical relevant topics such as shock driven radiative instabilities, secondary shock formation, and the seeding and amplification of galactic magnetic fields.

EXPERIMENTAL SETUP

ANALYSIS

CONCLUSIONS