Affiliations: Department of Mechanical Engineering and Intelligent
Systems, Tohoku Gakuin University, 1-13-1 Chuo, Tagajo, Miyagi 985-8537, Japan.
E-mail: norifumi@tjcc.tohoku-gakuin.ac.jp/koike@tjcc.tohoku-gakuin.ac.jp | Graduate School, Tohoku Gakuin University, 1-13-1
Chuo, Tagajo, Miyagi 985-8537, Japan
Abstract: A visual study of underexpanded plasma jet was conducted to reveal
the detailed behavior in the strong magnetic field. The images of the jet were
taken by a digital single-lens reflex camera through viewing windows. The
distribution of optical intensity obtained from the raw data was compared to
that of the typical emission line intensity. The profile of the optical
intensity agrees well with that of the emission intensity. It is illustrated
that the typical structure of underexpanded jet such as Mach disk is also
affected obviously by the magnetic field. The radial distribution of number
density was determined by using the image analysis based on the Abel-inversion.
The converted data clarify the jet behavior that is hidden on the ordinary
observation. The density obtained from numerical analysis for a simple gas was
also compared with the number density. It is confirmed from the comparison with
numerical results that the radial profile of number density can be utilized for
understanding the plasma jet behavior under the strong magnetic field.
Keywords: Plasma, Jet, Functional fluid, Magnetic field, Image analysis, Abel-inversion