Electron tuning of frequency in gyrotrons

Formulas for shifts of gyrotron autooscillation frequency due to change of electron beam parameters are presented. The frequency shifts can be commensurable with the frequency band of the beam-unloaded cavity. The autooscillation frequency is most sensitive to the change of the magnetic field, less to the change of the anode voltage and least to the the change of the beam voltage. Experiments presented are in satisfactory agreement with the theory.The authors wish to thank M.I. Petelin for his interest to the present work.     

Theoretical and experimental investigation of x-band two-cavity gyroklystron

Using self-consistent field theory, the interaction of electron flow with HF fields in a gyroklystron has been analized. Optimal parameters of its output cavity corresponding to the maximum efficiency have been found. Experimental study of dependence of the efficiency on Q-factor and length of the output cavity has been carried out. The results of simulation are in good qualitative agreement with experimental data.     

On one mechanism of spurious oscillations in high-power gyrotrons

One of the problems encountered in the design of high-power gyrotrons is the need to ensure stable single-mode generation. The conditions of spurious self-excitation in a gyrotron resonator have been studied fairly completely, and methods for its suppression have been developed (see Petelin [1] and Nusionvich [2], for example). At the same time, stable gyrotron operation can also be disrupted by the generation of spurious oscillations in the transition region between the electron gun and the resonator, where the electromagnetic field is nonuniform. A theoretical basis for this assumption is provided by results [1, 3, 4] indicating a fairly high efficiency of interaction of a high-frequency field with an electron current guided by a nonuniform magnetostatic field.Institute of Applied Physics, Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 37, No. 11, pp. 1458–1472, November, 1994.     

Heterogeneous reactions of H and O<Subscript>2</Subscript> with solid alkanes

The paper describes a new source of surface organic radicals whose special feature is a low rate of the initiation of alkyl radicals in reactions of H atoms with the surface of alkanes. A special reactor design was used to accumulate radicals at room temperature and observe alkoxyl radicals RO by the EPR method. For this purpose, alkanes were deposited on aerosil and placed into an EPR cavity. Thanks to the large area of aerosil loads (～10³ cm²), we were able to obtain a stable signal corresponding to a ～10¹⁷ total amount of alkoxyl radicals (the degree of surface coverage ～0.1%). When O₂ was introduced into the reactor in concentrations of 10¹⁵–10¹⁶ cm^?3, a sharp decrease in the signal from surface organic radicals was observed. The process was described as the first-order (RO) _s + O₂ → HO₂ + ketone reaction with a 1.7 × 10^?17 cm³ s^?1 rate constant.     

Development and Experimental Study of a Pulsed Megawatt Gyroklystron Operating in the Long-Wavelength Part of the Millimeter-Wavelength Range at IAP RAS

Radiophysics and Quantum Electronics - We have developed and studied experimentally a two-cavity gyroklystron operating at a frequency of 35 GHz and the cavity mode TE0 2 1 in a cryomagnet. The...     

Plasma-chemical technology of treatment of halogen-containing waste including polychlorinated biphenyls

We consider the developed plasma-chemical technology of halogen-containing substances treatment. The paper contains the experimental plant schematic and the positive results obtained after the treatment of tetrafluoromethane, ozone-damaging freon 12, polychlorinated biphenyls (PCB), the waste containing fluoride and chloride organics. The technology is proposed for industrial application.     

Thermodynamic study of characteristics of the converter with separated supply of hydrocarbon fuel for thermo-oxidative and steam reforming

Thermodynamic studies of the converter characteristics were performed to produce hydrogen-containing syngas from hydrocarbon fuel (kerosene) with its separated supply for thermo-oxidative and steam reforming. It is demonstrated that the optimal conditions of the converter performance correlate with the oxidant ratio of α > 0.5 at the heattransfer wall temperature of 1200 K. Hydrogen content in the final syngas reaches 60 % by volume, free carbon (soot) deposition in reforming products is excluded, and there is no need to apply walls water cooling in the converter.     

Catalytic activity of chromium,manganese, vanadium,tungsten, and molybdenum oxides in the hydrogenation of ethylene

Conclusions The catalytic activity of the oxides of Cr, W, Mn, Mo, and V in the hydrogenation of ethylene increases with decrease in the degree of oxidation of the cation.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1679–1680, July, 1977.     

The state of water in Y-type zeolites

Conclusions By titration with Fischer's solution and thermodesorption the authors show that the firmly combined water conteat of Y-type zeolites depends on the nature of the ion-exchange cation and the heat-treatment conditions.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 276–279, February, 1976.