Comparison of three hohlraum configurations with six laser entrance holes for indirect-drive inertial confinement fusion

Abstract

The radiation drive asymmetry and laser-plasma instabilities (LPIs) inside the conventional cylindrical hohlraum configuration are two daunting issues in indirect-drive inertial confinement fusion. Recently, an octahedral spherical hohlraum (SH) (Lan et al 2014 Phys. Plasmas 21 010704), a novel three-axis cylindrical hohlraum (TACH) (Kuang et al 2016 Sci. Rep. 6 34636), and an advanced three-axis elliptical hohlraum (TAEH) (Jing et al 2017 arXiv:1703.01579) with six laser entrance holes (LEHs) were proposed to mitigate these issues. In this paper, the performance of these three new hohlraum configurations is compared. Preliminary simulations indicate that the TAEH (with a case-to-capsule ratio, CCR = 2.8) could provide excellent radiation symmetry, comparable to those inside the SH (CCR = 5.1) and TACH (CCR = 2.2). The filling time of plasma affecting the LPIs is between those of the SH and TACH, and about 1.5 times the one in the ignition hohlraum Rev5-CH (300 eV) of the National Ignition Campaign (Haan et al 2011 Phys. Plasmas 18 051001). The energy coupling efficiency of the TAEH is about 29% and 17% greater than those inside the SH and TACH, respectively. Moreover, all three configurations have robust symmetry with respect to laser beam pointing errors and capsule offset, with the SH being the most insensitive.