Plasma Diagnostics for a Laser Driven Expansion into a Large Ambient Magnetized Plasma

The expansion of a laser plasma into a large (17m x 0.6m) magnetized plasma across or at 45$^\circ$ to the 275 G background field is studied with Langmuir and Mach probes. A special probe geometry allows data collection inside a diamagnetic bubble formed during the laser plasma expansion. We also observe Alfv\'en and MHD fast waves far away from the target. In the case of an expansion 45$^\circ$ from the background field we detect fast ion motion in the chamber and present Monte Carlo simulations of the ion trajectories.