A Model for First-Wall Thermal Response to Plasma Energy Deposition

A primarily analytical thermal analysis model is presented which allows for calculation of temperatures in fusion reactor first walls. The model utilizes input from plasma physics calculations coupling a 2-1/2 dimensional geometric analysis with a 1-dimensional heat conduction treatment to determine temperature profiles over the surface of and within the first wall. The results are primarily applicable to the steady-state operation of magnetic confinement devices such as tokamaks. Effects of wall geometry, toroidal curvature, and wall corrugation are considered in computing local power loadings from bremsstrahlung, cyclotron radiation, charged particles, and neutrons. Temperature solutions based on these loadings are developed by expanding into a MacLaurin series and utilizing the principle of superposition. A sequential calculation scheme is employed in lieu of traditional matrix methods in determining temperature distributions in composite walls. The model and corresponding solution methods are applied to three illustrative fusion reactor designs. Significant gains in accuracy are indicated over thermal analysis methods previously used.