Protection of IFE First Wall Surfaces from Impulsive Loading by Multiple Liquid Layers

A large, vertical shock tube is used to explore the breakup and mitigation effects of liquid layers expected from the hydrodynamic shock generated in an inertial fusion reaction. Single and multiple layers of water are tested at two Mach numbers, 2.12 and 3.20. X-ray radiography techniques are used to image the breakup of the water layer resulting in a quantitative measure of the mass fraction distribution of water after shock impact. The amount of breakup is increased with the addition of multiple layers and the increased breakup decreases the end wall impulse. The speed of the transmitted shock wave can be reduced by 50% and is a weak function of the number of layers. The peak pressure at the end-wall of the shock tube is significantly increased due to the high impulsive force of the single liquid layer, however this pressure is substantially reduced when multiple layers containing the same mass of water are used