A low-frequency (𝑓 < 2 kHz) potential structure (LFPS) is observed in a linear magnetic plasma device using Langmuir probe arrays. The center frequency of this structure is near zero. This structure has azimuthal and axial symmetries while with a finite radial wavenumber. The complete 3D spectra features of this structure have been identified to have the characteristics expected for zonal flows.

Plasma source is the most important part of the laboratory plasma platform for fundamental plasma experimental research. Barium oxide coated cathode plasma source is well recognized as an effective technique due to its high electron emission current. An indirectly heated oxide coated cathode plasma source has been constructed on a linear magnetized plasma device. The electron emission current density can reach 2 A/cm 2 to 6 A/cm 2 in pulsed mode within pulse length 5-20 ms. A 10 cm diameter, 2 m long plasma column with density 10 18 m −3 to 10 19 m 3 and electron temperature Te 3-7 eV is produced. The spatial uniformity of the emission ability is less than 4% and the discharge reproducibility is better than 97%. With a wide range of the plasma parameters, this kind of plasma source provides great flexibility for many basic plasma investigations. The detail of construction and initial characterization of oxide coated cathode are described in this paper.

In order to investigate electron dynamics near the electron diffusion region in magnetic reconnection process, an upgrade in the linear magnetized plasma (LMP) device is accomplished at the University of Science and Technology of China. Radio frequency (RF) helicon discharge is used to generate a quasi-stationary plasma, and a time-dependent magnetic field is applied to the plasma, which exhibits an X-type neutral point in vacuum. A two-dimensional sophisticated mobile platform is built up, providing a high spatial resolution, below 0.5 mm, for the diagnostics.