[en] A title listing is included for each of the 13 included papers

[en] The magnicon belongs to the class of high power RF sources, where a modulation is provided by the beam circular deflection and it is an advanced version of a gyrocon. The first magnicon has been built and tested in Novosibirsk in the middle of the 80's. The power of 2.6 MW has been obtained for the frequency 91.5 MHz and pulse duration 30 mcsec. The electron efficiency has been 85%. Good results obtained during investigations show that the magnicon can be an adequate RF source for the next generation of accelerators, especially for future linear colliders and accelerators for transmutation of nuclear waste. The magnicon conception described in the present paper allows to increase significantly the beam perveance, compared with the first magnicon, and to achieve the pulse power of tens and hundreds megawatts at the beam voltage not greater than 400-600 kV. The device is an amplifer working in frequency doubling mode and is a prototype of a RF source for linear colliders with high acceleration gradient. The magnicon is designed for an output power of 50 MW, an operating frequency of 7 GHz and a pulse duration of 2 mcsec

[en] Gyroamplifiers are very promising sources of coherent, phase-controlled, powerful electromagnetic radiation for driving future particle accelerators. At a given wavelength the interaction space in gyroamplifiers is much larger that that for klystrons. Therefore, gyroamplifiers usually operate at short wavelengths where the problem of miniaturization of the interaction space is, for conventional klystrons, extremely severe. Two years ago the operation of relativistic gyroklystrons in a 10 GHz frequency range was successfully demonstrated. The next step in the gyroamplifier development is directed towards improvement of electronic efficiency, enhancement of radiated power and an increase in operating frequency. The authors present some concepts of relativistic gyroamplifiers aimed at improving these output parameters

[en] The authors present a progress report on a program to develop a high-power X-band magnicon amplifier for accelerator applications. The goal of the program is to generate 50 MW at 11.4 GHz with 50% efficiency, using a 200 A, 500 keV electron beam produced by a cold-cathode diode on the NRL Long-Pulse Accelerator Facility. The initial experiment, designed to study the gain from the first (driven) deflection cavity to a second (passive) deflection cavity, has recently begun

[en] The stability of gyrotwistrons against the excitation of parasitic modes is studied. A method is described which can be used to compute the nonlinear saturation amplitude of the parasites when the operating mode is present. An example relevant to driving particle accelerators (near 10 GHz and 500 kV) is discussed

[en] A Josephson junction 1.6 mm wavelength microwave source has been used to demonstrate the parametric amplification by reflection necessary to maintain parametric oscillations at 1.6 mm wavelength. A perturbation calculation based on the resistively and capacitively shunted Josephson junction model gives a negative effective microwave resistance for a junction biased at voltages higher than the voltage for a cavity induced step. The parametric oscillation was observed at voltages consistent with the region in which negative resistance was calculated

[en] A 1 μs pulse-length, high-current relativistic klystron is being developed with a desired peak output power of 1 GW at 1.3 GHz. The tube consists of an input cavity, a single idler cavity, and an output cavity. Power levels as high as 475 MW have been experimentally observed. Current experimental results are presented. Physics and engineering issues affecting klystron performance are discussed

No abstract available

[en] Possibility of frequency control in vircators by means of beam parameters, magnetic field and external microwave signal has been studied. The conditions have been found when generated frequency doesn't depend on magnetic field B but radiation power has resonant dependence on B. It has been shown that some vircators can operate at two frequencies simultaneously

No abstract available