Laser beam profile design to mitigate the two plasmon decay instability for inertial confinement fusion conditions

The Two Plasmon Decay (TPD) instability is a preheat concern for inertial confinement fusion (ICF), where electron plasma waves are generated by the instability of laser light encountering near quarter-critical plasma densities. This talk characterizes the effect of an incident beam's electromagnetic (EM) orbital angular momentum (OAM) on the growth rate of the TPD instability. Attention is paid to the conservation of angular momentum throughout the TPD process as it is transferred from the OAM of the EM field to the mechanical angular momentum of particles. The light propagation and TPD processes are simulated using the Laser Plasma Simulation Environment (LPSE). Several beam profiles, constructed from the superposition of Laguerre-Gaussian or Hermite Gaussian modes, have been compared with regards to their stability to TPD, culminating with a profile that minimizes the growth rate. The talk concludes with a discussion of how the simulated profiles can be experimentally created through the use of contemporary beam shaping techniques.