Image: Gert Brodin
Research group The plasma theory group focuses on plasma regimes where collective dynamics meet quantum mechanical and quantum electrodynamical (QED) theory. Quantum plasma effects become important in high-density plasmas, where the electron Fermi temperature exceeds the thermodynamic temperature of the system.
Methods to analyse these types of systems are based on the von Neumann equations for the density matrix and typically involve transformation techniques, for example, Wigner transformations and/or Foldy-Wouthuysen transformations. Quantum electrodynamical plasma effects become important in the regime of strong electromagnetic fields, which can be approached with modern high-intensity lasers, where the electromagnetic intensity may exceed 1022 W/cm2. Theoretical studies are based on the so-called Dirac-Heisenberg-Wigner formalism, or on relativistic kinetic plasma theory complemented by QED transition rates for processes of interest, for example, nonlinear Compton scattering.
Comparison of numerical calculations and analytical theory for wave damping due to electron-positron pair creation when varying the plasma density. The curve represents analytical predictions, and the blue dots represent the numerical results.
ImageFrom “Linear pair-creation damping of high-frequency plasma oscillations” Phys. Plasmas 29, 042106 (2022)
