Potential importance of ultra-deep penetration for operation of IFE power plants

• Ultra-deep penetration of target fragments can be dangerous for inertial fusion energy (IFE) power plants.
• Low-density Xe does not protect the reactor chamber from some target fragments.
• Formation of fragments of hohlraums and/or cones seems to be unavoidable.

Possibility of damage of inertial fusion energy power plants caused by ultra-deep penetration of fragments of targets with hohlraums and/or cones for fast ignition has been investigated in this study. Some issues related to the formation of high-velocity solid and liquid fragments of targets and their deceleration and heating in the reaction chamber filled with low-density Xe gas have been studied. It was found that with a Xe gas mass density of approximately 6 μg/cm3 and reaction chamber internal radius of 6 m, a liquid spherical gold fragment with a radius of 5–7 μm could reach the chamber wall with a velocity >1 km/s.