Performance of Plasma Cathode for a Magnetized Sheet Plasma Device

Sheet shaped plasmas are produced by coupling magnetic field and plasma confined in a small volume from which electrons for the discharge current are extracted. Two schemes to couple a plasma cathode and downstream plasma, magnetic field adjustment and electrostatic confinement, have been tested. They were compared with respect to their stability and power efficiency for forming the downstream plasma. The operation of a small plasma cathode equipped with a pair of electro magnets produced a plasma with a good efficiency, but it often caused noise that made characterization of plasma parameters with a Langmuir probe impossible. An electrostatic confinement type plasma cathode had produced much quieter plasma, compared with a magnetic confinement type plasma cathode.