Magnetic Reconnection in High-Energy Density Laboratory Plasmas

This project involved theoretical research on radiative magnetic reconnection in High-Energy Density (HED) plasmas, with applications to laboratory laser-plasma experiments [on facilities like OMEGA (LLE) and NIF (LLNL)] and to astrophysical systems, such as accreting black hole coronae and magnetospheres of strongly magnetized neutron stars (magnetars and pulsars). Relativistic magnetic reconnection is a leading candidate mechanism for powering high-energy flares and persistent emission in various astrophysical systems.The extremely high energy density found in many of these systems dictates that reconnection should proceed in the radiative regime, where radiation back reaction on the electrons (and, if present, positrons), manifested, e.g., as radiative cooling and radiative drag on reconnection-driven bulk flows, plays an important role. Moreover, under some conditions, the energy of the emitted photons is so high that they can readily produce electron-positron pairs, e.g., in black-hole accretion disk coronae and in pulsar and magnetar magnetospheres. Due to recent rapid developments of experimental capabilities in HED physics, we can now for the first time seriously contemplate studying these exciting physical processes in the laboratory. This project investigated fundamental physics of magnetic reconnection in this novel regime, by performing several computational [using radiative particle-in-cell (PIC) simulations] and theoretical studies.