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Calabazas Creek Research, Inc. is developing a 10 kW CW, high efficiency, S-band, Periodic Permanent Magnet (PPM) focused klystron capable of driving accelerator cavities. The presentation will describe the design, computational analysis, and measured results. Measurements will be compared to simulation results from the large signal codes KLSC and Tesla.
Effective electromagnetic coupling with electronic equipment at radiation is used by a high power microwave (HPM) weapons source which means a relativistic backward wave oscillator in here. In the process of researching, developing and using HPM source, we have been studying a real “effective coupling” source which is able to attack the overall target, suitable in all situation ns. The experimental...
A novel three-dimensional finite-element (FE) modeling technique without matching meshes for the eigenmode analysis of arbitrary lossy slow-wave structures (SWSs) of traveling-wave tubes (TWTs) is presented. By simulating many examples, it is shown that the cold parameters of SWSs can be accurately and quickly obtained without matching meshes when using this technique. This technique would make the...
A 2M CW, RF load for gyrotrons was designed, built, and tested. A rotating launcher distributes the RF power along the loss surfaces. In addition to improving the heat dissipation, arcing caused by constructive interference is avoided. Several loads have been delivered, and the latest performance measurements will be presented.
Technological and design parts of plasma spraying metal-porous cathodes manufacturing for high-power multi-beam klystron are presented. The samples of cathode assemblies and their parameters are shown when operating in real devices. The results of investigations of the cathodes emission properties in the forced temperature conditions are presented in order to determine the maximum current density...
This paper presents details about the proposed TM/TC interface for TESATs future Microwave Power Modules. A brief overview on CAN bus related applications at TESAT, details of the current interface implementation, and development activities in this area will be given.
Efforts are continuing to improve the quality of controlled porosity reservoir cathodes and measure performance. CPR cathodes are being incorporated into several new configurations, including a magnetron injection gun, 15-beam klystron, and a Pierce gun for a 50 MW X-Band klystron. Improved computational tools assist users in CPR cathode design.
This program is developing high power windows fabricated from single crystal sapphire that provide superior mechanical properties. A key requirement is a robust surface coating to suppress multipactor emission. This program developed an innovative process that chemically bonds titanium nitride to the surface, providing a significant improvement over sputtered coatings.
We present the hot test results of a 220 GHz, serpentine waveguide vacuum electron amplifier showcasing a novel embedded monofilament microfabrication technique based on UV-LIGA. The instantaneous operating bandwidth exceeds 15 GHz and the small signal gain of the circuit is over 14 dB. By varying the voltage slightly, an operating bandwidth of almost 40 GHz is realizable with a minimum circuit gain...
We have studied the electromagnetic properties of a bi-helix slow wave structure surrounded by an azimuthally conducting screen formed by metal rings with and without capacitive gaps. The dependence of phase velocity on frequency and on the geometric parameters of the rings were measured on prototypes and analyzed. Novel designs of the bi-helix SWSs with circular metallization on the diaphragm supports...
In this paper, we examine methods in which plasmas can be used to tune the responses of RF/microwave periodic structures and artificially-engineered materials. In particular, we exploit microwave-induced plasmas created in periodic structures when the power of the incident electromagnetic wave exceeds the breakdown threshold power level. Based on the nature of the plasma created within the unit cell...
The U.S. Naval Research Laboratory has been developing a novel UV-LIGA process to create amplifier circuits from 100 GHz through the THz. A 670 GHz EIK ladder test piece has been successfully fabricated with a 0.004 inch diameter beam tunnel, and demonstrates sub-micron fabrication accuracies. The technique is being extended to showcase capabilities at 850 GHz, and 1.03, 1.35 and 1.50 THz.
Method of obtaining sintered and pressed composed materials based on BaxSr1−xHfO3, where x = 0.25, 0.50, 0.75, with 16, 20, 24, 60 % W (by mass), and experimental results of thermionic properties investigations of these materials are represented. The composition of 80% Ba0.75Sr0.25HfO3 — 20% W (by mass) is characterized by the thermionic current density of 1014 A/cm2 at T = 1620 K.
Present magnetic undulators have shortcomings at short periods making them expensive to construct, operate and maintain. The Asymmetric Immersed Pole (AIP) undulator concept avoids many of these complexities by using soft iron to convert axial to transverse field. This paper presents results from an investigation of AIP undulators.
We proposed a novel evaluation method of heat dissipation capability of the helix slow-wave structure (SWS). A distributed micro fiber Bragg grating (FBG) sensor array is designed to measure the temperature distribution of the helix in SWS. An experiment on two X-band SWSs of different heat dissipation capability is made and the results show that our method can effectively be used to estimate and...
The model based on coupled impedance electrodes was used to analyze effectiveness of a sheet e-beam interaction with the in-phase mode of a slow wave. The coupling coefficient, characterizing the interaction effectiveness, was calculated using derivatives of the equivalent parameters, the specific capacitances and inductance. The calculated coefficient was compared with that of a cylindrical e-beam...
At restricted anode voltage output power of multibeam klystron is limited by amount of beams. It depends on the diameter of ferrules in microwave cavities which is limited by a half of wavelength. Special design of the cavity filled with artificial metamaterial increases phase velocity and wavelength inside the gap which makes possible to increase significantly the diameter of ferrules, total current...
We consider the possibility to replace an electron beam (EB) by a "hot" equivalent capacitance that will make it possible to use "hot" equivalent circuits and long lines for analysis the EB interaction in TWTs. A sheet EB in the field of the in-phase mode of the slow wave excited by coupled impedance electrodes is considered in this paper.
A novel high-power oscillator based on the gyroklystron amplifier with external delayed feedback is designed and tested. The oscillator produces 1–1.5 MW peak power with nearly 1 μs pulse duration in Ka-band.
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