GB677992A - Improvements in electronic tubes - Google Patents

Abstract

677,992. Particle accelerators. PHILCO CORPORATION. Oct. 4, 1948 [March 20, 1948], No. 25849/48. Class 39 (i). [Also in Group XL (b)] A charged-particle accelerator includes a helical waveguide 33 into which high-frequency energy may be coupled and a particle gun 22 ... 26 for generating a particle beam and directing it axially of the waveguide, the pitch of the waveguide progressively increasing in the direction of movement of the beam to accelerate the particles as a result of the increasing axial velocity component of the travelling wave produced by the increasing pitch. As shown, the high-frequency energy is generated in the device itself by a similar waveguide 32 of uniform pitch acting as a travelling-wave oscillator and arranged between the gun and the accelerating guide, and coupled to waveguide 33 by loop 65 passing through partition 70. Both guides are formed from helicoidal strips contained within a conducting cylinder 31, guide 33 being terminated by a tapered block 61 of lossy material. The accelerated particles may be allowed to fall on an electrode 27 to provide a high voltage across condenser 75, or upon an X-ray target or a substance to be modified by bombardment with electrons. In an application to a high-voltage cathode-ray tube, Fig. 2 (not shown), the structure including the two waveguides 32, 33 is accommodated in the neck of the tube and the accelerated electrons are focused and deflected over a fluorescent screen, thus permitting high voltage operation without external sources of dangerously high voltage. Specifications 677,986, 677,990 and 677,991 are referred to.