Symmetry and stability physics in laser fusion. Chapter 6

To achieve a high pellet gain in inertial fusion, most of the DT fuel must be kept isentropically cold and be compressed to a high density. In the center of this cold fuel there will be a lower density, hot DT fuel region that will serve as the spark plug, or ignitor. In current inertial fusion pellet designs, this ignitor has a radius that is about 2% of the initial pellet shell radius. This requirement of an isentropically cold, dense fuel surrounding a much hotter, lower-density ignitor places fundamental requirements on the symmetry and the stability of an implosion. (author). 38 refs., 14 figs