An advanced three-axis elliptical hohlraum for indirectly driven inertial confinement fusion

TL;DR

This paper proposes an advanced three-axis elliptical hohlraum (TAEH) that balances radiation symmetry, plasma filling time, and coupling efficiency, offering a promising alternative for indirect-drive inertial confinement fusion ignition.

Contribution

The introduction of the TAEH design demonstrates improved performance metrics over existing hohlraum configurations through preliminary simulations.

Findings

TAEH provides excellent radiation symmetry comparable to SH and TACH.

Plasma filling time of TAEH is between SH and TACH, close to NVCH.

Coupling efficiency of TAEH is significantly higher than NVCH, SH, and TACH.

Abstract

The radiation symmetry and laser-plasma instabilities (LPIs) inside the conventional cylindrical hohlraum configuration are the two daunting challenges on the approach to ignition in indirectly driven inertial confinement fusion. Recently, near-vacuum cylindrical hohlraum (NVCH), octahedral spherical hohlraum (SH) and novel three-axis cylindrical hohlraum (TACH) were proposed to mitigate these issues. While the coupling efficiency might still be a critical risk. In this paper, an advanced three-axis elliptical hohlraum (TAEH) is proposed to make a compromise among these hohlraum performance. Preliminary simulations indicate that the TAEH (with a case-to-capsule ratio, CCR=2.8) could provide excellent radiation symmetry during the thorough laser pulse of the high-foot drive, comparable to the ones inside the SH (CCR=5.1) and TACH (CCR=2.2). The filling time of plasma affecting the LPIs is between those of SH and TACH, and about 1.5 times of that in the ignition hohlraum Rev5-CH of NIC and close to the one inside the NVCH (CCR=3.4). In particular, the coupling efficiency is about 22%, 29% and 17% higher than the one inside the NVCH, SH and TACH, respectively. It would be envisioned that the proposed hohlraum configuration merits consideration as an alternative route to indirect-drive ignition, complementary to the traditional cylindrical hohlraum and the proposed recently novel hohlraums.