Scaling of hot electron generation mechanisms from two-plasmon decay in ICF plasmas*

In Inertial Confinement Fusion (ICF) scenarios, particularly in Shock Ignition (SI), Hot Electron (HE) generation is a key aspect which can have different consequences, both positive, such as shock pressure increase, and detrimental, such as loss of ablation pressure and fuel preheat.

HEs are generated by Landau Damping of Electron Plasma Waves (EPW), which in turn are produced by Stimulated Raman Scattering (SRS) and Two Plasmon Decay (TPD) instabilities.

While radiative hydrodynamic codes used in ICF sometimes implement models for HE transport, they lack predictive capabilities regarding HE generation by laser/plasma instabilities. The aim of this work is to develop new models for hydrodynamic codes for HE produced by such instabilities.

We use the hybrid code LPSE to study HE quantities (HE fraction, temperature, etc.) as functions of laser and plasma parameters (laser intensity, plasma temperature, etc) for the TPD instability.

Here we propose scalings of HE generation for TPD in 2D and 3D for intensity, temperature and density scale length, in the presence of non-linear saturation mechanisms such as Parametric Decay Instabilities (PDI) and electrostatic wave collapse, and dynamic evolution of EPW Landau damping rate from electron test particles.