Stopping power in a dense nonequilibrium quantum plasma using quantum kinetic theory

Generation of warm dense matter in the laboratories is a nonequilibrium process in which non-adiabatic effects and strong excitation play an important role. Predicting the properties of the plasma, such as the stopping power, during this process, therefore, requires the use of a suitable nonequilibrium approach. We use Nonequilibrium Green's functions (NEGF)[1] combined with the Generalized Kadanoff-Baym Ansatz [2] to simulate ion stopping in a cylinder symmetric uniform warm dense plasma. Correlation effects are taken into account via the selfenergy Σ for which we use the static second Born approximation as well as the full dynamical screening selfenergy (GW) which generalizes the Balescu-Lenard collision integral to short time scales [1] and allows us to self-consistently include plasmons, instabilities and the screening dynamics. We first demonstrate that we are able to reproduce linear response results for quantum plasmas and then extend the simulations to nonequilibrium targets as well as to dense proton beams. Our results could be of relevance e.g. to the fast ignition by fast protons approach [3] to inertial confinement fusion that has sparked interest in recent years.

[1] M. Bonitz, Quantum Kinetic Theory (Springer, 2016)

[2] P. Lipavský, V. Špicka, B. Velický, Phys. Rev. B 34, 6933 (1986)

[3] M. Roth, et.al. Phys. Rev. Lett. 86, 436 (2001)