Effect of Dynamic Screening on DT Ion Collisions

In experiments at the National Ignition Facility, fusion is achieved by creating multi-keV energetic Deuterium and Tritium ions which interact via the Coulomb force. Most calculations of the scattering angle between ions assume the ions are in a vacuum. Expressions for ion collision rates in a plasma usually rely on Debye screening. However,the screening properties of a plasma are well known to depend on the particle velocity, a concept known as dynamic screening. Dynamic screening could change the ion-ion collision rates and, due to the anisotropic nature of the dynamically screened potential, lead to anisotropic scattering expressions. We will explore these ideas with a two-body interaction model that includes an arbitrary potential of interaction. First, we benchmark our model against Rutherford scattering and scattering in a plasma with static (Debye) shielding. Finally, we address the question of how the interaction changes accounting for dynamic screening, with a focus on the scattering angle. This could have implications for collision rates and fusion properties used in advanced codes that model NIF implosions.