Magnetic Reconnection of an Externally Applied Magnetic Field in a High-Energy Density Plasma

An experiment on magnetic reconnection of an externally applied magnetic field in counter-propagating high-energy density plasmas was conducted on the OMEGA EP Laser System.\footnote{L. J. Waxer\textit{ et al.}, Opt. Photonics News \textbf{16}, 30 (2005).} Two counter-propagating plasma flows were created by irradiating oppositely placed plastic (CH) targets with 1.8-kJ, 2-ns laser beams. An external magnetic field was imposed perpendicular to the plasma flow by MIFEDS (magneto-inertial fusion electrical discharge system).\footnote{O. V. Gotchev\textit{ et al.}, Rev. Sci. Instrum. \textbf{80}, 043504 (2009).} The magnetic field has a null-x-point geometry with $B=5\mbox{\thinspace T}$ at the targets. The plasma interaction was imaged by laser-driven, fast-proton radiography. The radiography images demonstrate formation of a pair of counter-propagating magnetized ``ribbons'' that collide and reconnect at the midplane. The results will be compared with particle-in-cell simulations and interpreted with predictions from the \textit{DRACO} code. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944, and NLUF Grant DE-SC0008655.