Laser-plasma diamagnetism in the presence of an ambient magnetized plasma

This work is an experimental study of the diamagnetic cavity created by a dense laser-produced plasma (initially, nlpp/n0≫1) expanding into an ambient magnetized background plasma (n0=2×1012 cm−3) capable of supporting Alfvén waves. The experiments are carried out on the upgraded Large Plasma Device [W. Gekelman, H. Pfister, Z. Lucky, J. Bamber, D. Leneman, and J. Maggs, Rev. Sci. Instrum. 62, 2875 (1991)] at UCLA. Two-dimensional data of both the diamagnetic cavity as well as visible light emission are presented and found to be rich in structure with spatially similar characteristics. Laser-plasma diamagnetism has been observed to be relatively unaffected by the presence of a background plasma for nlpp/n0≈10 at time of peak diamagnetism.