Dynamics of plasma reconfiguration after pellet injection in Heliotron J

Because of the many degrees of freedom in magnetized plasmas, the plasma is largely reconfigured when the plasma achieves a non-equilibrium steady state in response to changes in the internal environment. Here we report observations of a plasma reconfiguration process when the density is increased by pellet injection in Heliotron J. The plasma shows no adiabatic response to pellet injection and achieves an improved confinement during the reconfiguration process. It was found that plasma shrinking and expansion arose and the magnetic field line structure in the divertor region also changed in the plasma reconfiguration process.