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Latest development and experimental study of a W-band gyro-TWA with a helically corrugated waveguide and a cusp electron gun are presented. With an input seed signal from an 1.5 W, 90–96 GHz solid state source a gain of 27 dB was measured from the experiment. The bandwidth of the gyro-TWA was measured to be at least 5 GHz.
Micro-reentrant square cavities operating at high order modes have been demonstrated to be a viable solution for the realization of millimeter wave klystrons. However, the excitation of the required high order mode is a challenging task. The realization and measurement of a novel coupler for high order mode cavities is proposed.
Pseudospark electron beams of micro-sizes have been measured recently and their application to millimeter-wave and terahertz radiation generation is being investigated. A three cavity 94 GHz klystron using a micro-sized beam has been designed and simulated and is currently being constructed.
Gyrotrons find use in several diverse fields, ranging from plasma heating and plasma diagnostic to spectroscopy and materials processing. However, with demand for high power coherent radiation at THz frequencies, the confining magnetic fields required for gyrotrons operating at the fundamental harmonic become increasingly restrictive. However, considerable promise lies with the concept of the gyro-multiplier...
Results from numerical simulations have demonstrated the principle of a co-harmonic gyrotron, operating with a novel cavity. Such a cavity is capable of generating coherent radiation at both the 2nd and 4th harmonics of the electron cyclotron frequency simultaneously, at frequencies of 37.5 GHz and 75 GHz. Further results are presented here, including refinements to the output section of the cavity,...
A 390 GHz harmonic gyrotron based on a cusp electron gun was designed to operate on a TE71 mode and the 7th cyclotron harmonic of a large orbit electron beam. This beam is produced by a cusp electron gun with a voltage of 40 keV, a current of 1.5 A and an adjustable velocity ratio from 1 to 3. Smooth cylindrical waveguide was studied and built as the interaction cavity. The relationship between the...
A small-scale pseudospark discharge is being investigated as the electron beam source for a klystron operating at a frequency of 94 GHz and single-gap discharge experiments have been carried out. The klystron has been designed using the particle-in-cell (PiC) code MAGIC-2D and simulated output looks promising.
A multicavity microklystron operating in the terahertz region has been designed and simulated. This microklystron will be driven by an electron beam sourced by a down-scaled pseudospark discharge.
A novel interaction cavity has been designed for a gyro-oscillator, allowing co-harmonic generation at the 2nd and 4th harmonic resonances of the cyclotron frequency. The output aperture of the cavity has been designed to trap the lower harmonic, whilst allowing output of the upper harmonic. Results from recent numerical simulations, performed using MAGIC 3-D, are presented. The intended co-harmonic...
Based on previous experimental investigations on pseudospark (PS) discharges, a small-scaled PS electron beam source was conceived to drive a 200 GHz microklystron. Recent PS e-beam experiments producing a beam of 1 mm in diameter and klystron interaction simulations will be presented. The microklystron will be fabricated using micro-electro-mechanical systems (MEMS) construction techniques.
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