GB935197A - Glow discharge pump apparatus - Google Patents

Abstract

935,197. Discharge apparatus. VARIAN ASSOCIATES. May 17, 1961 [May 27, 1960; June 30, 1960], No. 18014/61. Class 39 (1). A glow discharge getter pump comprises within a sealable envelope 3, an anode member 4, a sputter member 7, and a collector member 7 positioned between the anode and sputter members and having a plurality of apertures therein, means 29 for applying a magnetic field in a direction transverse with respect to the said members, means for maintaining the anode member at a positive potential relative to the sputter member so that a glow discharge takes place, and means for maintaining the collector member at a potential intermediate those of the anode and sputter members. The anode 4 is preferably a rectangular grid thereby defining a plurality of discharge cells, and a further electrode transparent to ions may be provided so as to defocus the ions incident on the sputter member. In operation, the anode is at 9000 volts, the collector at 8000 and the sputter member is earthed, so that electrons accelerated towards the anode 4 will have a spiral orbit, thus forming, by bombardment, positive ions which are either attracted to the sputter member at high velocity thereby releasing sputter material or are deposited on the collector member at relatively low velocity and are subsequently covered with sputter material. The anode 4 is preferably of titanium, and the sputter electrode formed of titanium, chromium, zirconium, gadolinium or iron.