Observation of the colliding process of plasma jets in the double-cone ignition scheme using an x-ray streak camera

Abstract

The double-cone ignition scheme is a novel approach with the potential to achieve a high gain fusion with a relatively smaller drive laser energy. To optimize the colliding process of the plasma jets formed by the CHCl/CD shells embedded in the gold cones, an x-ray streak camera was used to capture the spontaneous x-ray emission from the CHCl and CD plasma jets. High-density plasma jets with a velocity of 220 ± 25 km/s are observed to collide and stagnate, forming an isochoric plasma with sharp ends. During the head-on colliding process, the self-emission intensity nonlinearly increases because of the rapid increase in the density and temperature of the plasma jets. The CD colliding plasma exhibited stronger self-emission due to its faster implosion process. These experimental findings effectively agree with the two-dimensional fluid simulations.

The effect of high-Z dopant on the ablation of carbon–hydrogen polymer target

“…Spherical implosion experiments conducted by Hu and Fiksel et al [15,16] on OMEGA utilizing doped CH (7.4%Si) targets revealed that the inclusion of Si dopant led to an increased average ablation rate in hydrocarbon targets, resulting in a 2-3 fold reduction in the laser imprinting efficiency. Recently, double-cone ignition (DCI) experiments conducted by Liu et al [17] on SG-IIU, realize the colliding process of plasma jets using Cl-doped shell C 16 H 14 Cl 2 , which demonstrates the feasibility of using the CHCl target in daily DCI experiments.…”

“…Except for above mentioned high-Z dopants, other dopants such as chlorine (Cl) [17,[20][21][22][23], germanium (Ge) [24][25][26][27][28], silicon (Si) [29], titanium (Ti) [30,31], iodine (I) [32] are also used. For their excellent performance in preventing hot electron preheating, mitigating hydrodynamic instability and facilitating target diagnosis, high-Z dopant has been a widely used method in ICF target design.…”

“…In this paper, we choose Cl as a dopant with the guidance of previous DCI studies [17,[20][21][22]. The impact of high-Z dopant in planar CH targets on the ablation characteristic parameters is investigated through radiation hydrodynamic simulations, including the laser absorption rate, the temperature, the ablation pressure and the mass ablation rate.…”