Apparatus and method for generating brillouin electron flow

摘要

943,485. Electron beam apparatus. ZENITH RADIO CORPORATION. April 8, 1960 [April 10, 1959], No. 12646/60. Heading H1D. In a method of producing an electron beam that exhibits Brillonin flow, a beam of electrons is accelerated within, and parallel to, a magnetic field, and is first converged and then permitted to diverge before again being subjected to a gradually increasing convergent field until the beam attains a resultant crosssectional area at which the net radial forces acting on its electrons approach zero. As shown, all but a small proportion, e.g. 1%, of the electrons emitted by cathode 10 are intercepted by first anode 13. The potentials, relative to the cathode, of anodes 13, 15, 17, 18 are 8, 150, 15 and 7 volts respectively, so that the beam passing through anode 13 is converged to a minimum cross-section in the region of anode 15 and afterwards diverges until, after passing anode 17, it is again subjected to a convergent electrostatic lens system for aligning the beam envelope parallel with the tube axis. Two further anodes 32, 33 may be provided to intercept marginal electrons and accurately define the beam envelope. The electron gun may be used in a parametic amplifier, Fig. 3 (not shown), of the kind described in Specification 929,015.