A general nonlinear multi-dimensional interaction theory is employed to analyze Brillouin focused beams in klystrons and traveling-wave amplifiers. Harmonic currents and beam spread are found for a number of different situations. Closed-form solutions are being sought for the nonlinear equations. Beam stability in the presence of r-f and velocity distribution effects on the start-oscillation conditions of BWO's are two specific problems where these solutions are to be applied. Experimental programs to check these analyses are described. An appropriate taper on a ring-and-bar circuit for obtaining phase-focused operation is presented. Progress on the magnetron injection gun computer program is described. The trajectory starting problem appears to be solved, while further work on establishing the proper current density from the cathode is indicated. Provisions in the relativistic electron beam computer program for self-induced effects are also described. The status of the UHF helix-magnetron injection gun device is summarized. Performance data of the gun in a beam analyzer is presented. (Author).

Research was continued on a study of large signal traveling-wave tubes. Extensions on the two-dimensional large-signal analysis for klystrons and traveling-wave tubes are presented. Space-charge effects and the effects of stream subdivisions and the number of charge groups chosen are shown in a number of graphs. The work on the nonlinear theory of multistream microwave devices by a density function method is summarized. An improved method of handling the coupling between positive and negative velocity regions was worked out. Experimental test results on several phase-focused tubes are presented. Efficiency enhancements obtained by this method as well as a simple depressed potential collector are described. The test results obtained on the ring-and-bar tube before it had to be rebuilt are also listed. Several additional minor changes made on the solid beam digital computer program are described. Futhermore the status of the program for solution of magnetron injection guns is discussed. (Author).

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