Review of the three candidate hohlraums in ICF

TL;DR

This review compares three ICF hohlraum geometries—cylindrical, octahedral, and six-cylinder-port—highlighting their strengths, weaknesses, and potential for improved fusion ignition performance.

Contribution

It provides a theoretical comparison of three hohlraum designs, proposing a new six-cylinder-port design that balances key performance factors.

Findings

Cylindrical hohlraums face drive asymmetry issues but can still achieve ignition with more laser energy.

Octahedral hohlraums offer high symmetry but have complex plasma-related problems.

Six-cylinder-port hohlraums combine advantages of both designs, balancing energy, symmetry, and plasma interactions.

Abstract

In this paper, we give a review of three hohlraum geometries, including cylindrical, octahedral and six-cylinder-port hohlraums, in inertial confinement fusion (ICF) mainly from theoretical side. Every hohlraum has its own strengths and weaknesses. Although there is a problem of drive asymmetry in the cylindrical hohlraums due to some non-ideal factors, the success of ignition is still possible if more laser energy is available beyond the US National Ignition Facility (NIF) in the future. Octahedral hohlraums can provide the high symmetry flux on capsule. However, octahedral hohlraums suffer from several problems due to the complicated three-dimensional plasma conditions inside. And up to now, there is no one target design with the octahedral hohlraums in which each problem can be solved at the same time. Six-cylinder-port hohlraums combine the merits in theory of both cylindrical and octahedral hohlraums to a certain extent. We introduce a target design with good performance by using the six-cylinder-port hohlraums, in which the key issues of concern, such as laser energy, drive symmetry, and laser plasma interaction (LPI), etc, are all balanced.