Towards Integrated X-Ray Energy Deposition and Ablation Simulations on Flibe Jet Dynamics for the Athena Fusion Pilot Plant Using OpenFOAM

Within the Athena Fusion Pilot Plant design, liquid jets consisting of molten flibe will be used to protect the chamber wall from X-ray and neutron radiation. The interaction of X-ray radiation with molten salt jets can induce rapid volumetric heating and phase-change phenomena. Understanding the response of the molten salt jets to X-ray radiation is vital to design the chamber size in inertial fusion energy devices. In this work, we used OpenFOAM to investigate the response of a 100-µm-radius droplet and a 5-mm-radius droplet and the proposed liquid jet array to significant energy deposition from X-rays produced by target implosion within the chamber. Two methods of approximating the X-ray energy deposition are discussed. The mass of vaporized flibe and the maximum pressure experienced within the chamber are determined, which is critical to inform chamber design and optimization. We also study the formation of liquid jets in three dimensions to determine a suitable repetition rate for the power plant.