Currents and shear Alfvén wave radiation generated by an exploding laser-produced plasma: Perpendicular incidence
نویسندگان
چکیده
Examples of one plasma expanding into another and the consequent radiation of wave energy are abundant in both nature and the laboratory. This work is an experimental study of the expansion of a dense laser-produced plasma ~initially, nlpp /n0@1) into a magnetized background plasma (n0 52310 cm) capable of supporting Alfvén waves. The experiments are carried out on the upgraded Large Plasma Device ~LAPD! at UCLA @W. Gekelman et al., Rev. Sci. Instrum. 62, 2875 ~1991!#. It has been observed that the presence of a background plasma allows laser-plasma charge separation to occur that would otherwise be limited by large ambipolar fields. This charge separation results in the creation of current structures which radiate shear Alfvén waves. The waves propagate away from the target and are observed to become plasma column resonances. Conditions for increased current amplitude and wave coupling are investigated. © 2003 American Institute of Physics. @DOI: 10.1063/1.1564598#
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