GB1312906A - Charged particle beam scanning device with electrstatic control - Google Patents

Abstract

1312906 Discharge tubes NORTHROP CORP 16 Nov 1971 [16 Nov 1970] 53222/71 Heading H1D Charged particles from an area source 16, Fig. 1, pass to an area target 14 via control electrodes 25-30 provided with aligned apertures, each control electrode being provided on each face with a pair of electrodes arranged in the same pattern. The pattern may be arranged as shown with the electrodes connected to associated bi-stable circuits 75-79 so that only one channel is open to passage of particles, according to the states of the circuit 75-79; one electrode of each pair is connected to a negative potential Vc and the other to a positive potential which is V 1 or V 2 in alternate plates, these alternating potentials serving to focus the particles along the open channel or channels. Corresponding electrodes on opposite sides of a control electrode are preferably connected by conductive linings in the channels (Fig. 2, not shown); the diameter of a channel is preferably equal to its length and to the width of a spacer plate (not shown in Fig. 1) separating adjacent control electrodes, this distance being 0À015 inch when V 1 and V 2 are 10 and 15 volts respectively. The arrangement shown includes a lens plate 20 having an accelerating potential connected between conductive surfaces on its two faces, a modulation plate 50, and one or more dynode plates 54. The particles are preferably electrons but could be positive or negative ions, and the source may be a radio-active coating of tritium.