Physical studies of fast ignition in China

Abstract

Fast ignition approach to inertial confinement fusion is one of the important goals today, in addition to central hot spot ignition in China. The SG-IIU and PW laser facilities are coupled to investigate the hot spot formation for fast ignition. The SG-III laser facility is almost completed and will be coupled with tens kJ PW lasers for the demonstration of fast ignition. In recent years, for physical studies of fast ignition, we have been focusing on the experimental study of implosion symmetry, M-band radiation preheating and mixing, advanced fast ignition target design, and so on. In addition, the modeling capabilities and code developments enhanced our ability to perform the hydro-simulation of the compression implosion, and the particle-in-cell (PIC) and hybrid-PIC simulation of the generation, transport and deposition of relativistic electron beams. Considerable progress has been achieved in understanding the critical issues of fast ignition.

Anomalous neutron yield in indirect-drive inertial-confinement-fusion due to the formation of collisionless shocks in the corona

“…Minimizing the non-implosion neutron yield remains a challenge for the full-scale direct-drive fast ignition. In order to reduce the hot electron preheating, indirect-drive FI experiments have been performed on the SG-II upgrade and the SG-III prototype laser facilities [4,5]. In contrast to the direct-drive scheme, the nanosecond laser beams first strike the inside wall of a high-Z hohlraum to produce an x-ray radiation bath, which then ablates and implodes the fuel capsule.…”

Enhanced Proton Acceleration by Laser-Driven Collisionless Shock in the Near-Critical Density Target Embedding with Solid Nanolayers

“…Ion acceleration via laser-plasma interaction [1] has attracted extensive attention with the rapid development of ultrashort, ultraintense laser technology in recent decades. For its unique characteristics such as high energy and small divergence [2], it has potential scientific applications in a variety of aspects such as inertial confinement fusion (ICF) [3][4][5][6], tumor therapy [7,8], and proton imaging [9,10]. Several mechanisms for laserdriven ion acceleration have been proposed and observed experimentally over the past decades, including target normal sheath acceleration (TNSA) [11,12], radiation pressure acceleration (RPA) [13][14][15], break-out afterburner (BOA) [16,17], magnetic vortex acceleration (MVA) [18,19], and collisionless shock acceleration (CSA) [20][21][22].…”