GB882781A - Improvements in ionic pump - Google Patents

Abstract

882,781. Discharge apparatus. GENERAL ELECTRIC CO. Sept. 23, 1959 [Sept. 25, 1958]. No. 32389/59. Class 39(1) In a getter pump there is a cathode anode collector and magnetic field positive ions being entrapped on the collector by particles sputtered from the cathode on to the collector, the collector being unscreened from the cathode by any other electrode. In one form, Fig. 1, there are two hemispherical cold cathodes 2, 3 associated with optional thermionic filaments 11, 12 of tungsten, an annular or honeycomb anode 4 and cylindrical collectors 5 and 6. The electrodes or flanges thereon are sealed to annular ceramic spacers 7, 8, 9, 10; preferably 2, 3, 4, 5, 6 are of Ti and 7, 8, 9, 10 of matching expansion characteristics such as foresterite. The cathodes 2, 3 and preferably also the anode are of Ti, Zr or Hf. The anode 4 and collectors 4, 5, 6 are energised by an A.C. or D.C. source 117 and a solenoid 116 or permanent magnet sets up an axial magnetic field. The cathodes 2, 3 are in general of curved or discontinuous shape. There may be only a single collector, Fig. 2 (not shown). The leads have bell shaped glass members to prevent breakdown, Fig. 3 (not shown). In another form, Fig. 4 (not shown) a single thermionic cathode of Ti, Zr or Hf and directly or indirectly heated has a cylindrical surrounding anode and end plate collectors of Ni, fernico or Fe.