Experimental Studies of Magnetic Reconnection in 3D Geometries Including Magnetic Nulls.

Magnetic reconnection is typically studied in nominal 2D magnetic geometries where the magnetic field remains finite through the domain. However, in natural occurring reconnection the magnetic field geometry can be much more complex including 3D magnetic structures known as magnetic nulls. To elucidate the importance of magnetic nulls for magnetic reconnection we are proposing a new experimental setup in the Big Red Ball (BRB) at the Wisconsin Plasma Physics Laboratory. Plasma guns will be applied to create a back-ground plasma in a uniform magnetic field, where biasing can be applied to drive field aligned currents. A single magnetic coil will encircle the plasma column creating a physical-dipole field opposite to the back-ground field. As the coil-current is increased two double null are created and the 3D magnetic geometry is expected to interrupt the plasma column in a 3D magnetic reconnection burst. At oblique angles of the coil the complexity of the magnetic field geometry increases dramatically, and will be characterized by the arrays of magnetic diagnostics available on (BRB).