LAUSR

Glow discharge with a cylindrical hollow cathode mounted on a process vacuum chamber has been studied in a wide range of gas pressures from 0.01 to 10 Pa. The chamber serves as the discharge anode. A diaphragm is fastened on the cathode end to protect the discharge plasma inside the chamber from contamination with the sputtered cathode material. The discharge characteristics depend on area So of the diaphragm orifice. A double layer appears at the orifice when So < S* ≈ (2 m/M)1/2S, where m is the electron mass, M is the ion mass, and S is the cathode surface area. Electrons accelerated in the double layer effectively ionize the gas and can produce, inside the chamber, a plasma with the same density as inside the cathode. At the gas pressure less than ∼0.3 Pa, the low-voltage double layer can be replaced with a high-voltage accelerating gap between the plasma inside the cathode and the plasma produced inside the chamber by a beam-plasma discharge.Glow discharge with a cylindrical hollow cathode mounted on a process vacuum chamber has been studied in a wide range of gas pressures from 0.01 to 10 Pa. The chamber serves as the discharge anode. A diaphragm is fastened on the cathode end to protect the discharge plasma inside the chamber from contamination with the sputtered cathode material. The discharge characteristics depend on area So of the diaphragm orifice. A double layer appears at the orifice when So < S* ≈ (2 m/M)1/2S, where m is the electron mass, M is the ion mass, and S is the cathode surface area. Electrons accelerated in the double layer effectively ionize the gas and can produce, inside the chamber, a plasma with the same density as inside the cathode. At the gas pressure less than ∼0.3 Pa, the low-voltage double layer can be replaced with a high-voltage accelerating gap between the plasma inside the cathode and the plasma produced inside the chamber by a beam-plasma discharge.