Formation of a Sporadic Plasma Jet from a Disrupting Magnetic Flux Tube

We investigate the rear-end collision process of dense plasma blobs moving along a magnetic flux tube with weak axial current. This is done using a resistive three-dimensional MHD code. We obtain a new elementary excitation called a "moving solitary magnetic sausage" that can develop near the interface of colliding plasma blobs. The characteristic of the moving solitary magnetic sausage is that it has an isolated magnetic surface ring of a knot structure with a pair of radially converging and expanding flows. This can be excited in a magnetic flux tube with very weak axial current. The excitation can propagate along a magnetic flux tube like a drill by making a hole of weak magnetic field. This is in contrast to a moving solitary magnetic kink, which can be excited in a magnetic flux tube with relatively strong axial current. Below in our investigation, we study the collision process of two moving solitary magnetic sausages along a slightly bent magnetic flux tube. It is shown that a bent magnetic flux tube can be explosively disrupted during the collision of two moving solitary magnetic sausages. We also find sporadic plasma jets that occur in this process, guided along a current sheet with reverse magnetic fields from the disrupting magnetic flux tube. The formation of sporadic plasma jets may be applicable to a variety of unsteady, transient, jetlike phenomena observed in the solar transition region and chromospheric plasmas.