ABSTRACT
Radiation is an important mechanism of energy transfer when an inertial confinement fusion (ICF) target is irradiated by laser light or ion beams. It can affect the implosion process, the ignition conditions, and the thermonuclear burn of the target. In case of heavy-ion beams impinging ICF targets, it has been observed that the absorbed energy in the outer parts of the target is transported inward by thermal electrons and radiation processes, which would preheat the fuel, thereby reducing the final compression. The approximate models to the radiation transfer equation are analyzed in this chapter to simulate the evolution of an ICF target in terms of the energy balance, in order to compute how much energy is transported by radiation. Models based on the diffusion approximation, which has been used for a large number of numerical computer codes, will first be analyzed and criticized for ICF targets.
