RadHeat V1 User's Manual

RadHeat is a one dimensional finite difference heat transfer code that can determine the transient temperature evolution of layered targets in pulsed penetrating radiation environments. It makes use of energy dependent opacity and stopping data to model the volumetric deposition of any number of photon or ion spectra each incident at arbitrary angles. Convective and radiative boundary conditions are handled as well as the ability to impose any initial temperature profile. The heat diffusion equation is formulated implicitly to eliminate timestep dependent stability issues. Simulations are, therefore, able to achieve high fidelity during times of thermal activity and greater speed elsewhere. The prototypical physical situation simulated by RadHeat is illustrated. RadHeat was originally written to study the temperature response of tungsten-armored target-facing walls to the pulsed photon and ion radiation emanating from fusion microexplosions in future IFE power plants. RadHeat's implementation is quite general, though, and the code can be applied to a very broad range of problems. Anything from the heating of the Earth's crust on a warm summer day to the temperature rise in a mirror after a laser pulse could potentially be modeled. This manual was written to help new users learn how to run the code and introduce them to the simulation tools it provides.