GB941391A - Travelling wave tubes - Google Patents

Abstract

941,391. Travelling wave tubes. SPERRY RAND CORPORATION. Feb. 19, 1960, No. 5949/60. Addition to 815,459. Heading H1D. In a travelling-wave tube apparatus having a helix or other slow wave structure there are two polepieces 13, 21, one of which, 21, has a radial or nearly radial aperture for the passage of the end of the slow wave structure or a conductor connected thereto and surrounds the end of the slow wave structure and the other end of the slow wave structure or a conductor connected thereto is led out adjacent or longitudinally through the second polepiece 13. The far end of the other end of the slow wave structure or conductor connected thereto is brought out longitudinally, Fig. 1, or radially, Fig. 4 (not shown), or is brought out radially between the end of the helix and the collector-polepiece. In the latter case the magnetic field windings 47-49 are of conductive foil instead of wire. The feeders are coaxial lines and the polepieces 21 at the gun end also serves as the gun anode. The output end of the helix is a strip 25 of progressively increasing width and fused quartz blocks 18 space the inner and outer conductors of the output coaxial line. A vacuum-tight glass seal is shown at 38. The solenoids 47, 48, 49 are wound on a non-ferromagnetic former 46 and have non-ferromagnetic spacers 51-54. The magnetic field strength is adjusted by varying the energization of the three solenoids or by mechanically adjusting the relative position of the tube and focusing coils. The electron beam from spherically concave cathode button 19 has a minimum diameter at the entrance to the magnetic field. The helix has three ceramic support rods held in holes in the collector and which have a diameter less than or greater than the helix diameter. In the latter case the helix dispersion is compensated for.