Sheet Plasma Produced by Hollow Cathode Discharge

A sheet plasma is produced by a hollow cathode discharge under an axial magnetic field. The plasma is about40cm in length, 4cm in width and 1 cm in thickness. The electron density is about 10^8cm^-3. The hollow cathodeis made to be shallow with a large opening, which is different from the ordinary deep hollow cathode. A Langmuirprobe is used to detect the plasma. The electron density and the spatial distribution of the plasma change whenvoltage, pressure and the magnetic field vary. A peak and a data fluctuation at about 200 G-300 G are observedin the variation of electron density (or thickness of the sheet plasma) with the magnetic field. Our work will behelpful in characterizing the sheet plasma and will make the production of dense sheet plasma more controllable.