Modelling collisions in a relativistic plasma

Generalising the work of Lenard and Bernstein, we introduce a new, fully relativistic model to describe collisional plasmas. Like the Fokker-Planck operator, this equation represents velocity diffusion and conserves particle number. However, unlike the Fokker-Planck operator it is linear in the distribution function, and so more amenable to a fluid treatment. By taking moments, we derive a new fluid model, and demonstrate the damping effects of collisions on Langmuir waves.