Gas transport and control in thick-liquid inertial fusion power plants

Among the numerous potential routes to a commercial fusion power plant, the inertial path with thick-liquid protection is explored in this doctoral dissertation. Gas dynamics phenomena in such fusion target chambers have been investigated since the early 1990s with the help of a series of simulation codes known as TSUNAMI. For this doctoral work, the code was redesigned and rewritten entirely to enable the use of modern programming techniques, languages and software; improve its user-friendliness; and refine its ability to model thick-liquid protected chambers. The new ablation and gas dynamics code is named "Visual Tsunami" to emphasize its graphics-based pre- and post-processors. It is aimed at providing a versatile and user-friendly design tool for complex systems for which transient gas dynamics phenomena play a key role. Simultaneously, some of these improvements were implemented in a previous version of the code; the resulting code constitutes the version 2.8 of the TSUNAMI series. Visual Tsunami was used to design and model the novel Condensation Debris Experiment (CDE), which presents many aspects of a typical Inertial Fusion Energy (IFE) system and has therefore been used to exercise the code. Numerical and experimental results are in good agreement.; In a heavy-ion IFE target chamber, proper beam and target propagation set stringent requirements for the control of ablation debris transport in the target chamber and beam tubes. When the neutralized ballistic transport mode is employed, the background gas density should be adequately low and the beam tube metallic surfaces upstream of the neutralizing region should be free of contaminants. TSUNAMI 2.8 was used for the first simulation of gas transport through the complex geometry of the liquid blanket of a hybrid target chamber and beam lines. Concurrently, the feasibility of controlling the gas density was addressed with a novel beam tube design, which introduces magnetic shutters and a long low-temperature liquid vortex; this beam tube configuration was included in the first thick-liquid heavy-ion fusion point design, the so-called Robust Point Design 2002. Additionally, novel, alternative thick-liquid chambers that can accommodate the assisted-pinch, the solenoidal final-focusing, or a Z-pinch driver are discussed.