Initial dynamics and stabilities of electrically non-neutral counter-differential rigid-rotation two-fluid equilibria by 2D3V PIC simulation

Most models standing from two-fluid plasma are required for plasmas to be electrically quasi-neutral. However, recent experimental works to verify models' predictions, such as the dynamics of electron–positron pair plasma around a pulser in space or transport of relative canonical helicity, use two non-neutral plasmas and thus naturally require its non-neutrality. This poster shows a stability analysis of counter-differential rigid-rotation equilibria of electrically non-neutral two-fluid plasma [1] by 2D3V PIC code and an experiment for its verification using a thin metal wire scheme [2]. In the equilibria, ion (i+) and e- plasmas with finite temperatures are confined cylindrically by a uniform magnetic field B exhibit corresponding rigid rotations around the plasma axis with different angular velocities ωi and ωe, which is attributed to the contribution from the diamagnetic drift of the i+ and e- plasma owing to its finite pressures. To analyze the stability, the PIC code calculates its time-evolution of the particle distributions Ni,e or density profiles ni,e of i+, and e- plasmas initially in the equilibria. The simulation results show that in its early stage, the plasmas are seen to oscillate in the radial direction, which is similar to a radial breathing mode in the cold case with a single electron plasma.