Effect of external longitudinal magnetic field on the dynamics of pulsed plasma stream

Abstract

A spectroscopic study is carried out to investigate pulsed plasma stream produced in a coaxial plasma accelerator under the influence of an external longitudinal magnetic field. The dynamics of Argon plasma stream that includes the excitations and emissions of plasma species and its different parameter variations on the application of an external longitudinal magnetic field is reported in this work. The behavior of the ionized and neutral species of argon plasma is studied from their intensity distribution profiles which indicates the occurrence of faster recombination as compared to field free case. The variation of pressure on the plasma stream reveal significant influence on the recombination and diffusion process of the plasma species. Moreover, the variation of cathode voltage leads to variation in input energy to the system which influences the ionization and excitation processes of the plasma species. A plasma density (Ne) jump is achieved from 1021-1022 m-3 at relatively higher pressure ~ 8 bar plenum pressure in presence of magnetic field. Saturation of the emissions and excitations of plasma species are revealed from intensity profile and electron excitation temperature (Texc) profile which occur at different pressure and voltage both for field and field-free cases. The electron temperature (Te) is estimated using FLYCHK code by comparing the simulated charge state distributions with the experimental findings. Using known parameters in the code, the different estimated Te shows a linear and an exponential decrement respectively in absence and presence of magnetic field. Maximum Te of 2.2 eV is reported which decreases to 1.51 eV at significant increase of plasma density of 1022 m-3.