Relaxation dynamics of plasma bubbles propagating into a background magnetized plasma

The interaction of the hot dense magnetized plasma with background plasma is of great interest in space plasma physics, for example in the propagation of coronal mass ejections in background solar winds at solar scales, and in expansion of the radio jets/lobes into the extragalactic medium at astrophysical scales. To investigate the relaxation dynamics of such interactions a compact coaxial magnetized plasma gun is used to launch a hot dense plasma into a background low density plasma generated in a linear device. Bubble plasmas are formed by a coaxial plasma gun, and with the appropriate operating parameters these bubbles form with spheromak-like equilibrium. It is observed that when the bubble plasma is injected into the background magnetized plasma rather than a vacuum, the bubble is deformed asymmetrically due to the magnetic tension force instead of smoothly relaxing to the minimum energy state of a spheromak-like configuration. At one edge of the bubble the growth of Magneto-Raleigh Taylor instability is observed. In order to characterize the density, temperature, and magnetic field configuration of the plasma bubble relaxation we have used the triple Langmuir probe and B-dot magnetic probe array. A visible spectrometer and a fast-framing camera are used to observe the evolution dynamics of the plasma bubble into the background plasma.