Plasma simulation efforts

Zero-temperature Poisson-Boltzmann solver

Given the numerical instability of the non-linear Poisson-Boltzmann equation, traditional solvers eventually breaks down at low temperature. A novel solver that solves the non-linear problem at the zero-temperature limit using the waterback model has been written to obtain the (quasi-)equilibrium plasma shape and density for the low temperature plasmas that exist in the ALPHA apparatus.

Classical Trajactory Monte Carlo (CTMC) collision simulation

A CTMC collision simulation using velocity-verlet pusher is written to analyse the interaction between antiprotons and positrons during mixing in the ALPHA apparatus.

Vlasov-Poisson solver

A Vlasov-Poisson solver based on a version used in [1] by Prof. Friedland has been adopted to simulating the autoresonance mixing scheme used in ALPHA. Together with the two previous solvers, various interactions between positrons, antiprotons and external electrostatic potentials are modeled, including space charge effects and Fokker-Planck collision. In this animation a antiproton cloud is being autoresonantly excited and injected across a positron plasma by oscillating an upstream electrode and chirping its frequency across the linear resonant frequency at the bottom of the antiproton well.

[1] Autoresonant Transition in the Presence of Noise and Self-Fields, I. Barth et al., Phys. Rev. Lett. 103, 155001 (2009)