The Promise of Magnetized Fuel: High Gain in Inertial Confinement Fusion

At the third International Conference on Emerging Nuclear Energy Systems [1], we presented computational results which suggested that “breakeven” experiments in inertial confinement fusion (ICF) may be possible with existing driver technology. Our computations used a simple zero-dimensional model to survey the parameter space available for magnetized fuel. The survey predicted the existence of a totally new region in parameter space where significant thermonuclear fuel burn-up can occur. The new region is quite remote from “conventional” parameter space and is characterized by very low fuel densities, very low implosion velocities, and, most importantly, driver requirements reduced by orders of magnitude [2]. Whereas our initial computations considered only the yield from a hot, magnetized central fuel, we have extended our simple model to include a “cold fuel” layer. In the same spirit as our earlier work, our extended model is intended to provide a starting point for more comprehensive investigations. Our extended model predicts that it is possible to obtain a large cold fuel burn-up fraction, leading to very high gain, and once again, the optimum parameter space is quite remote from that of conventional high gain targets. Although conventional drivers optimized for conventional targets are probably not optimum for magnetized fuel at its extremes, there is a continuum between the conventional parameter space and the new parameter space, suggesting a possible role for conventional drivers. However, it would appear that magnetized fuel warrants a complete rethinking of the entire driver/target configuration.