Experimental investigation of coaxial-gun-formed plasmas injected into a background transverse magnetic field or plasma

摘要

Injection of coaxial-gun-formed magnetized plasmas into a backgroundtransverse vacuum magnetic field or into a background magnetized plasma hasbeen studied in the helicon-cathode (HelCat) linear plasma device at theUniversity of New Mexico [M. Gilmore et al., J. Plasma Phys.81, 345810104(2015)]. Magnetized plasma jet launched into a background transverse magneticfield shows emergent kink stabilization of the jet due to the formation of asheared flow in the jet above the kink-stabilization threshold $0.1kV_A$ [Y.Zhang et al., Phys. Plasmas 24, 110702 (2017)]. Injection of a spheromak-likeplasma into a transverse background magnetic field led to the observation offinger-like structures on the side with a stronger magnetic field null betweenthe spheromak and background field. The finger-like structures are consistentwith magneto-Rayleigh-Taylor instability. Jets or spheromaks launched into abackground, low-$\beta$ magnetized plasma show similar behavior as above,respectively, in both cases.