Linear Theory of the Beam-Wave Interaction in the Arbitrary Cylindrical Cerenkov Device
24 Feb 2005-International Journal of Infrared and Millimeter Waves (Kluwer Academic Publishers-Plenum Publishers)-Vol. 26, Iss: 3, pp 375-386
TL;DR: In this paper, the dispersion equation in Cerenkov devices has been derived and analyzed numerically using the self-consistent linear theory, which can be applied to efficiently calculate all kinds of beam-wave interaction in different types of axisymmetric slow-wave structures (SWS) with arbitrary periodic profile.
Abstract: The “hot” dispersion equation in Cerenkov devices has been derived and analyzed numerically using the self-consistent linear theory. In principle, the linear analysis can be applied to efficiently calculating all kinds of beam-wave interaction in various Cerenkov devices composed of axisymmetric slow-wave structures (SWS) with arbitrary periodic profile. Then the results for Cerenkov devices with three typical SWS profiles are presented.
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TL;DR: In this paper, a method based on an eigenfunction expansion and the linearized Vlasov equation was proposed to study the beam-wave interaction in cylindrical surface corrugated waveguides with losses.
Abstract: A method based on an eigenfunction expansion and the linearized Vlasov equation to study the beam-wave interaction in cylindrical surface corrugated waveguides with losses is presented. The mathematical formulation is described in detail, and numerical results are given in comparison with the literature.
16 citations
Cites background or result from "Linear Theory of the Beam-Wave Inte..."
...The last comparison is with the results appearing in [14] for a rectangular corrugation profile for the case of TM and hybrid modes....
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...Recently, a structure with rectangular grooves has also been studied [14]....
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TL;DR: In this paper, the electron beam interaction in a novel slow-wave structure (SWS) called dielectric-lined azimuthally periodic circular waveguide (DLAP-CW) is analyzed in a linear frame.
Abstract: The electron beam interaction in a novel slow-wave structure (SWS) called dielectric-lined azimuthally periodic circular waveguide (DLAP-CW) is analyzed in a linear frame. Moreover, the linear gain characteristics of the DLAP-CW are obtained by the self-consistent relativistic field theory. Analytical solutions for the hot dispersion characteristics are derived, and the complicated dispersion equations have been numerically solved with MATLAB. The small-signal growth rate is calculated for dimensions of the improved SWS and the parameters of the electron beam. It is shown that selecting the appropriate thickness and location of the metal rods increases the small-signal gain (dielectric constant held fixed). In addition, the gain of the DLAP-CW increases as the beam current increases, and the beam voltage not obviously influences the small-signal gain. Furthermore, a comparison of the small-signal gain of this structure with a conventional dielectric-lined circular waveguide (DL-CW) is made, and the results validate that the novel SWS has an advantage over the DL-CW on the electron efficiency, potentially resulting in a higher gain traveling-wave-tube circuit.
4 citations
TL;DR: In this article, the microwave and terahertz frequency ranges, including plasma technologies, showed better interaction efficiency and higher output power as compared to apparatus with the same frequency range.
Abstract: Electronic technologies, especially in the microwave and terahertz frequency ranges, including plasma show better interaction efficiency and higher output power as compared to apparatus with the va...
2 citations
TL;DR: In this paper, the effects of geometrical and physical parameters such as dielectric, plasma and metal radii on the dispersion characteristics of terahertz transverse electric mode and its frequency spectrum are studied.
Abstract: The propagation of transverse electric mode in a cylindrical metallic smooth-wall waveguide contains a dielectric rod and a cold collisionless unmagnetized degenerate plasma layer is analytically investigated in the terahertz frequency region. The dispersion relations of fast and slow waves for this mode are derived and solved numerically. The effects of geometrical and physical parameters such as dielectric, plasma and metal radii, and dielectric permittivity on the dispersion characteristics of terahertz transverse electric mode and its frequency spectrum are studied. It is shown that the decrease of dielectric permittivity and metal radius, and the increase of degenerate plasma radius leads to higher frequency fast waves. It is also indicated that an increase in the dielectric radius results in a decrease in the frequency of fast waves. In addition, it is found that by reducing the dielectric rod radius and with increasing metal radius, the frequency is increased in the slow waves. Finally, it is shown that the increase in dielectric permittivity causes a decrease in the frequency of both fast and slow waves.
1 citations
TL;DR: In this article, an accurate and fast calculation method of the hot dispersion equation is derived for rectangular corrugated SWSs, which are widely used in the high frequency Cherenkov devices.
Abstract: When the wavelength of overmoded Cherenkov oscillator goes into Ka-band, power handling capacity becomes an essential issue. Using the TM02 mode or higher order TM0 n modes as the operating mode is a potential solution. This paper is aimed to find some proper parameters to make the temporal growth rate of the TM02 mode higher in our previously studied Gigawatt (GW)-class Ka band oscillator. An accurate and fast calculation method of the “hot” dispersion equation is derived for rectangular corrugated SWSs, which are widely used in the high frequency Cherenkov devices. Then, factors that affect the temporal growth rate of the high order TM0 n modes are analyzed, including the depth of corrugation, the radius of drift tube, and the diode voltage. Results show that, when parameters are chosen properly, the temporal growth rate of the TM02 mode can be as high as 0.3 ns−1.
References
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Book•
01 Jan 1992
TL;DR: In this article, the authors discuss the origins of high-power microwave systems, the systems approach to HPM, and the system approach to linking components into a HPM system.
Abstract: Contents Introduction Origins of High Power Microwaves High Power Microwave Operating Regimes Future Directions in HPM Further Reading References Designing High Power Microwave Systems The Systems Approach to HPM Looking at Systems Linking Components into a System Systems Issues Scoping an Advanced System Conclusion Problems References High Power Microwave Applications Introduction High Power Microwave Weapons High Power Radar Power Beaming Space Propulsion Plasma Heating Particle Accelerators Problems References Microwave Fundamentals Introduction Basic Concepts in Electromagnetics Waveguides Periodic Slow-Wave Structures Cavities Intense Relativistic Electron Beams Magnetically Insulated Electron Layers Microwave-Generating Interactions Amplifiers and Oscillators, High- and Low-Current Operating Regimes Phase and Frequency Control Summary Problems References Enabling Technologies Introduction Pulsed Power Electron Beams and Layers Microwave Pulse Compression Antennas and Propagation Diagnostics HPM Facilities Problems Further Reading References Ultrawideband Systems UWB Defined UWB Switching Technologies UWB Antenna Technologies UWB Systems Conclusion Problems References Relativistic Magnetrons and MILOS Introduction History Design Principles Operational Features Research and Development Issues Fundamental Limitations MILOs Crossed-Field Amplifiers Summary Problems References BWOs, MWCGs, and O-Type Cerenkov Devices Introduction History Design Principles Operational Features Research and Development Issues Fundamental Limitations Summary Problems References Klystrons and Reltrons Introduction History Design Principles Operational Features Research and Development Issues Fundamental Limitations Summary Problems References Vircators, Gyrotrons and Electron Cyclotron Masers, and Free-Electron Lasers Introduction Vircators Gyrotrons and Electron Cyclotron Masers Free-Electron Lasers Summary Problems References Appendix: High Power Microwave Formulary A.1 Electromagnetism A.2 Waveguides and Cavities A.3 Pulsed Power and Beams Diodes and Beams A.4 Microwave Sources A.5 Propagation and Antennas A.6 Applications Power Beaming Plasma Heating Index
670 citations
TL;DR: In this article, a comprehensive theoretical treatment is developed for backward wave oscillators composed of a relativistic electron beam guided by a strong magnetic field through a slow wave structure consisting of a cylindrical waveguide with a sinusoidally varying wall radius.
Abstract: In this paper, a comprehensive theoretical treatment is developed for backward wave oscillators composed of a relativistic electron beam guided by a strong magnetic field through a slow wave structure consisting of a cylindrical waveguide with a sinusoidally varying wall radius. This analysis, equally applicable to traveling wave tube operation, includes both a linearized theory of small‐amplitude perturbations and numerical simulations of the saturated, large‐amplitude operating regime. The variation of device operating characteristics with system parameters is examined in detail. Comparisons of the analytic and numerical results with experiments and additional calculations show excellent agreement and justify a high degree of confidence in the validity of the theory.
255 citations
TL;DR: In this article, the results of theoretical and experimental studies of a GW-class, large diameter microwave oscillator are presented, which consists of a large cross-section (overmoded), slow-wave structure with a unique profile of wall radius specifically designed to support surface waves and to provide a strong beam-wave coupling at moderate voltage (500 kV).
Abstract: Results of theoretical and experimental studies of a GW-class, large diameter microwave oscillator are presented The device consists of a large cross-section (overmoded), slow-wave structure with a unique profile of wall radius specifically designed to support surface waves and to provide a strong beam-wave coupling at moderate voltage (500 kV), an internal adjustable microwave reflector, a coaxial microwave extraction section, and a coaxial magnetically insulated field emission electron gun In preliminary experiments carried out at 83 GHz, the power level exceeding 05 GW and efficiency of 15% have been measured calorimetrically
159 citations
Journal Article•
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TL;DR: In this article, the authors explore the recent history and diversity of this remarkable technology, with emphasis on recent advances in the more traditional device types (traveling-wave tube and klystron), as well as more recent innovations such as the microwave power module, inductive output amplifier, fast-wave devices, ultrahigh-power sources, and RF vacuum microelectronics.
Abstract: This paper explores the recent history and diversity of this remarkable technology, with emphasis on recent advances in the more traditional device types (traveling-wave tube and klystron), as well as more recent innovations such as the microwave power module, inductive output amplifier, fast-wave devices, ultrahigh-power sources, and RF vacuum microelectronics. These advances can be credited to a combination of device innovation, enhanced understanding gained through improved modeling and design, the introduction of superior materials and sub-assembly components and the development of advanced vacuum processing and manufacturing techniques.
151 citations
TL;DR: In this article, a linear theory of the excitation of electromagnetic waves in a plasma-filled corrugated-wall waveguide with an arbitrarily large sinusoidal corrugation was derived and analyzed numerically.
Abstract: A linear theory of the excitation of electromagnetic waves in a plasma-filled corrugated-wall waveguide with an arbitrarily large sinusoidal corrugation has been derived and analyzed numerically. The theory predicts that, when driven by an electron beam, the presence of a plasma in the slow wave structure will cause an increase in the oscillation frequency, and that the temporal growth rates of a high-frequency mode approach those of the fundamental mode for high plasma densities. The latter result may account for the high-frequency modes observed in the authors' plasma-filled backward-wave oscillator. >
99 citations