Laser energy asymmetry-driven deflection of Au plasma jets in half-cylinder target and its interaction with CH corona plasma

Abstract

We investigate the formation of deflected gold $(\mathrm{Au})$ jets and their interaction with plastic $(\mathrm{CH})$ corona plasma, relevant to energy imbalances in the hohlraum for indirect drive inertial confinement fusion (ICF). Experiments and hydrodynamic simulations were performed using two laser pulses (1 ns pulse, 0.6 and 0.8 TW, respectively) with a $25 \%$ energy and power difference on the interior of an Au cylinder shell target. X-ray and optical imaging revealed distinct deflection structures and about 15-degree deflection of the Au plasma jets. When a deflected Au jet interacted with a CH planar target representing the ICF capsule ablator, significant compression of the CH corona was observed. Radiation magnetohydrodynamic simulations closely matched the experimental results. A temperature difference of 800 eV from the laser energy imbalance caused differential expansion of the Au bubbles, driving the jet deflection. During the Au-CH interaction, self-generated magnetic fields in the Au jets were significantly enhanced at the impact point, potentially generating super-hot electrons. These findings help in understanding the impact of deflected Au jets on the CH ablator corona plasma within ICF hohlraums. Such interactions may become a key issue to address in future applications of near-vacuum hohlraums.

Keywords

• inertial confinement fusion
• laser energy asymmetry
• deflected jet
• plasma collision
• shock