Enhanced X-ray emission arising from laser-plasma confinement by a strong transverse magnetic field

Evgeny D Filippov,Sergey A Pikuz,Mikhail Starodubtsev,Andrea Ciardi,Weipeng Yao,Jerome Béard,Sophia N Chen,Guilhem Revet,Jack Hare,Sergey S Makarov,Igor Yu Skobelev,Amira Guediche,Konstantin F Burdonov,Simon Bolaños,Denis Romanovsky,Julien Fuchs

doi:10.1038/s41598-021-87651-8

Abstract

We analyze, using experiments and 3D MHD numerical simulations, the dynamic and radiative properties of a plasma ablated by a laser (1 ns, 10^{12}–10^{13} W/cm^2) from a solid target as it expands into a homogeneous, strong magnetic field (up to 30 T) that is transverse to its main expansion axis. We find that as early as 2 ns after the start of the expansion, the plasma becomes constrained by the magnetic field. As the magnetic field strength is increased, more plasma is confined close to the target and is heated by magnetic compression. We also observe that after sim 8 ns, the plasma is being overall shaped in a slab, with the plasma being compressed perpendicularly to the magnetic field, and being extended along the magnetic field direction. This dense slab rapidly expands into vacuum; however, it contains only sim 2% of the total plasma. As a result of the higher density and increased heating of the plasma confined against the laser-irradiated solid target, there is a net enhancement of the total X-ray emissivity induced by the magnetization.

Highlights

We analyze, using experiments and 3D MHD numerical simulations, the dynamic and radiative properties of a plasma ablated by a laser (1 ns, 1012–1013 W/cm2 ) from a solid target as it expands into a homogeneous, strong magnetic field that is transverse to its main expansion axis
Permitted by the advent of new experimental facilities capable of developing strong magnetic fields[1,2,3], such investigations have led to major progress in diverse fields such as laboratory a strophysics[4,5,6,7,8,9,10,11,12] or inertial confinement fusion (ICF)
The presence of a strong magnetic field could substantially reduce the growth of hydrodynamic instabilities[14,22,23], enhance fuel compression; and a reduction in electron thermal conductivity, where it was shown that magnetization could increase the fuel ion temperature in ICF t argets[13]

Summary

Introduction

We analyze, using experiments and 3D MHD numerical simulations, the dynamic and radiative properties of a plasma ablated by a laser (1 ns, 1012–1013 W/cm2 ) from a solid target as it expands into a homogeneous, strong magnetic field (up to 30 T) that is transverse to its main expansion axis. Permitted by the advent of new experimental facilities capable of developing strong magnetic fields[1,2,3], such investigations have led to major progress in diverse fields such as laboratory a strophysics[4,5,6,7,8,9,10,11,12] or inertial confinement fusion (ICF) As for the latter, for example, via a reduction in electron thermal conductivity, it was shown that magnetization could increase the fuel ion temperature in ICF t argets[13]. As a combined result of higher density and increased heating, we find that the plasma emissivity in the X-ray region is enhanced by at least 50% by the 30 T magnetization, compared to that of the unmagnetized plasma

Methods

Results

Conclusion