Results 81 to 90 of about 198 (133)

Cathode and Anode Optimization in a Virtual Cathode Oscillator

IEEE Transactions on Dielectrics and Electrical Insulation, 2007
We are fabricating and testing several different types of cathodes for the same vircator driven by a single shot Marx generator and pulse forming line (300 kV, 60 ns, 30 Omega). The cathodes types, each with an emitting area of ~32 cm2, include the original velvet with a new geometry, carbon fiber, pin-array, and an array of all metal cathodes.
Y. Chen, J. Mankowski, J. Walter, M. Kristiansen, R. Gale   +4 more
openaire   +1 more source

Computer simulation of virtual cathode oscillations

Journal of Applied Physics, 1990
The dynamics of relativistic electron beam and the oscillations of the virtual cathode in the vircator (virtual cathode oscillator) have been investigated by electrostatic particle-in-cell computer simulations. A specially developed PIC (particle-in-cell) computer code is employed in this study. In the diode region, cathode to anode, the solid electron
Tsang-Lang Lin, Wen-Ting Chen, Wen-Chung Liu, Yuan Hu, Mien-Win Wu   +4 more
openaire   +2 more sources

Time–Frequency Analysis of Virtual-Cathode Oscillator

IEEE Transactions on Plasma Science, 2010
Time-frequency analysis has been carried out for microwave radiation from a virtual-cathode oscillator. The objective is to observe and understand the frequency behavior of virtual-cathode oscillation. The diagnostic results have given clear evidence of mode hopping and frequency shifting.
Weihua Jiang
exaly   +2 more sources

Analysis and simulation of virtual cathode oscillations

The Physics of Fluids, 1986
A nonlinear mechanism for virtual cathode oscillations is derived from an analysis of a cold plasma fluid model. Frequency scalings and field wave shapes are predicted. These are compared with extensive numerical simulation studies of non-neutral electron beams using both one- and two-dimensional particle-in-cell codes.
Abraham Kadish, Rickey J. Faehl, Charles M. Snell   +2 more
openaire   +1 more source

Virtual cathode oscillator (vircator) modes

12th International Conference on Microwaves and Radar. MIKON-98. Conference Proceedings (IEEE Cat. No.98EX195), 2002
Vircators as high-power microwave sources have been investigated for twenty years now. Computer simulations are important tools for vircator performance investigations. However, such simulations do not show the mechanisms involved. Two basic mechanisms are usually discussed: Bridges and Birdsall oscillations and Barkhausen-Kurz oscillations.
W. Czarczynski, J. Sobanski
openaire   +1 more source

Effects of electron beam focusing on virtual cathode formation in virtual cathode oscillator

2016 IEEE International Conference on Plasma Science (ICOPS), 2016
As a high power microwave (HPM) source, virtual cathode oscillator has been studied due to its simplicity. A lot of experiments on virtual cathode oscillator has been conducted and reported to study the characteristics and to increase its efficiency1, 2. In order to increase its efficiency, ballistic focusing of an electron diode has been studied3. And
Sehoon Kim, Chang Jin Lee, Young-Maan Cho   +2 more
exaly   +2 more sources

Hybrid microwave oscillators with a virtual cathode

Plasma Physics Reports, 2004
A review is given of the developments and theoretical investigations of a fundamentally new class of microwave devices, namely, hybrid microwave oscillators with a virtual cathode, which combine the useful properties of virtual cathodes with the advantages of those traditional microwave oscillators that operate with subcritical-current beams and have a
A. E. Dubinov, I. A. Efimova, K. E. Mikheev, V. D. Selemir, V. P. Tarakanov   +4 more
openaire   +1 more source

Oscillation Frequency of a Reflex-Triode Virtual Cathode Oscillator

IEEE Transactions on Electron Devices, 2011
The most fundamental issues in virtual cathode oscillator (vircator)-based high-power microwave devices are efficiency improvement and oscillation frequency control. We present a study of the time-dependent behavior of the oscillation frequency of a reflex-triode vircator for various anode-cathode (AK) gaps.
Amitava Roy, Archana Sharma, Sabyasachi Mitra, Rakhee Menon, Vishnu Sharma, K. V. Nagesh, D. P. Chakravarthy   +6 more
openaire   +1 more source

Modeling of Reflex Triode Virtual Cathode Oscillator

IEEE Transactions on Plasma Science, 2014
An investigation of the reflex triode virtual cathode oscillator based on simulations with 3-D particle-in-cell code developed by ATK Mission Systems is done. The device model is based on an actual experimental setup with 15-mm anode–cathode gap. The obtained simulation results use a single-shot 200-kV, 300-ns pulse at anode. Numerical analysis is done
Ayush Saxena, Faruk Kazi
exaly   +2 more sources

Virtual Cathode Oscillator Component Optimization

Conference Record of the 2006 Twenty-Seventh International Power Modulator Symposium, 2006
Recent research efforts at TTU include a simple aluminum cathode for E-beam generation in a virtual cathode oscillator (vircator) [1]. As a continuation of these results, we are fabricating and testing several different types of cathodes for the vircator driven by a Marx generator and a pulse forming line (400 kV, 60 ns, 30 ?).
Yeong-Jer Chen, John Mankowski, John Walter, Magne Kristiansen   +3 more
openaire   +1 more source