Decoupled rocket model of a spherical shell implosion in inertial confinement fusion

Abstract

In inertial confinement fusion, the rocket model has achieved great success in describing many important effects, including the residual mass of the shell, average implosion velocity, the motion of the ablative surface, and rocket efficiency (the ratio of the kinetic energy of the shell to absorbed energy). This model uses only the implosion parameter to describe the spherical ablative implosion dynamics under the thin-shell assumption. In this paper, we introduce a decoupled rocket model using an additional parameter that extends beyond the thin-shell assumption to describe the implosion dynamics at the same time. This provides information for the theoretical design of a thick shell by optimizing two parameters rather than only one implosion parameter. To demonstrate this, we apply these two models to design single-shell targets driven by the same radiation source. Our simulations show the decoupled rocket model can get better theoretical design results in a larger parameter space.