  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.
