Magnetic structure formation in super-Alfvénic, quasi-perpendicular expansion of laser-produced plasma into magnetized ambient plasma at high repetition rates*

We present two-dimensional mapping of a super-Alfvénic (M_A > 1) carbon, laser produced plasma (LPP) as it expands into an ambient, magnetized helium plasma. The formation and propagation of a magnetic structure is observed in the ambient plasma that separates a relatively large distance (~0.5 d_i) from the bulk diamagnetic cavity (~d_i). This structure is observed to coincide with the focusing of the LPP ions into a jet like structure from magnetic pressure forces that act perpendicularly to both the magnetic field and bulk LPP direction of travel. The data was acquired during recent experiments performed on the Large Plasma Device (LAPD) at the University of California, Los Angeles as part of a series of experiments recreating conditions observed in Earth’s magnetosphere for study in the laboratory. The acquisition of this data requires a high repetition rate (~ 1 Hz) as each dataset represent thousands of laser shots in order to fully investigate the two-dimensional region of interest.