Particle-in-cell simulations of low-β magnetic reconnection driven by laser interaction with a capacitor–coil target

Abstract

The dynamics of low-$\beta$ magnetic reconnection (MR) driven by laser interaction with a capacitor-coil target are reexamined by simulations in this paper. We compare two cases MR and non-MR (also referred as AP-case and P-case standing for the anti-parallel and parallel magnetic field lines, respectively) to distinguish the different characteristics between them. We find that only in AP-case the reconnection electric field shows up around the X line and the electron jet is directed toward the X line. The quadruple magnetic fields exist in both cases, however, they distribute in the current sheet area in AP-case, and out of the squeezing area in P-case, because electrons are demagnetized in the electron diffusion region in the MR process, which is absent in P-case. The electron acceleration is dominant by the Fermi-like mechanism before the MR process, and by the reconnection electric field when the MR occurs. A power-law electron energy spectrum with an index of 1.8 is found in AP-case. This work proves the significant potential of this experimental platform to be applied in the studies of low-$\beta$ astronomy phenomena.