Output characteristics of the high-power microwave generated from a coaxial vircator with a bar reflector in a drift region

Jeon, Wook; Lim, Jeong Eun; Moon, Min Wug; Jung, K.B.; Park, Won-Bae; Shin, Hang-Sik; Seo, Yoonho; Choi, Eun Ha

doi:10.1109/tps.2006.875729

Cited by 35 publications

(2 citation statements)

References 12 publications

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“…The generation of highpower microwaves usually requires a complete system to achieve, which consists of the energy and the vacuum chamber (diode, microwave source and radiation antenna) [5,6]. Typically, to generate high-power microwave radiation, the pressure inside the vacuum chamber must not be less than 5.0 × 10 −2 Pa. After a discharge pulse, the cathode emits electrons and releases gas with a high voltage and high current, which can degrade the vacuum environment inside the device [7][8][9]. The conventional method of maintaining the vacuum is to use an external vacuum pumping set, which is not conducive to the integration of the microwave source system due to the large volume of the vacuum pump set and the limited pumping capacity.…”

Section: Introductionmentioning

confidence: 99%

A Dynamic Pumping Model for a Vacuum-Sealed Gigawatt Repetitively Operated High-Power Microwave Source

et al. 2022

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In this study, a dynamic pumping model was established for a vacuum-sealed, gigawatt-class, repetitively operated transit-time oscillator (TTO) based on the direct-simulation Monte Carlo (DSMC) method, and the pressure distribution of the model at different times and locations was analyzed. The simulation results showed that the maximum pressure at the diode was an order of magnitude larger than the equilibrium pressure, and the pressure recovery time was three times the duration of a single pulse. To verify the accuracy of the simulation results, experiments were conducted in a vacuum-sealed hard-tube TTO structure with a repetition rate of 10 Hz and the pressure was monitored at the vacuum diode. The diode voltage was about 500 kV and the beam current was 8 kA. Further, the average microwave power was 1 GW with a pulse width of 40 ns. The experimental results revealed that the equilibrium pressure at the vacuum diode was 4.0 × 10−3 Pa, and the pressure recovery time was three times the duration of a single pulse. These results were consistent with the simulation results, which indicates that the proposed model can provide technical support for subsequent vacuum-maintenance experiments.

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Section: Introductionmentioning

confidence: 99%

A Dynamic Pumping Model for a Vacuum-Sealed Gigawatt Repetitively Operated High-Power Microwave Source

et al. 2022

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“…In order to enhance the conversion efficiency of high power microwaves ͑HPMs͒ the coaxial vircators have been proposed. 3 The coaxial vircator is made of a cylindrical electron beam diode which consists of an annular cathode and grounded mesh anode.…”

Section: Introductionmentioning

confidence: 99%

Electron beam current in high power cylindrical diode

et al. 2010

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Intense electron beam generation studies were carried out in high power cylindrical diode to investigate the effect of the accelerating gap and diode voltage on the electron beam current. The diode voltage has been varied from 130 to 356 kV, whereas the current density has been varied from 87 to 391 A/cm2 with 100 ns pulse duration. The experimentally obtained electron beam current in the cylindrical diode has been compared with the Langmuir–Blodgett law. It was found that the diode current can be explained by a model of anode and cathode plasma expanding toward each other. However, the diode voltage and current do not follow the bipolar space-charge limited flow model. It was also found that initially only a part of the cathode take part in the emission process. The plasma expands at 4.2 cm/μs for 1.7 cm anode-cathode gap and the plasma velocity decreases for smaller gaps. The electrode plasma expansion velocity of the cylindrical diode is much smaller as compared with the planar diode for the same accelerating gap and diode voltage. Therefore, much higher voltage can be obtained for the cylindrical diodes as compared with the planar diodes for the same accelerating gap.

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Focus of high-power microwaves with positive and negative zone plate to increase the receiving power in axial virtual cathode oscillator

Jang

Mumtaz

Lee

et al. 2021

Current Applied Physics

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Output characteristics of the high-power microwave generated from a coaxial vircator with a bar reflector in a drift region

Cited by 35 publications

References 12 publications

A Dynamic Pumping Model for a Vacuum-Sealed Gigawatt Repetitively Operated High-Power Microwave Source

A Dynamic Pumping Model for a Vacuum-Sealed Gigawatt Repetitively Operated High-Power Microwave Source

Electron beam current in high power cylindrical diode

Focus of high-power microwaves with positive and negative zone plate to increase the receiving power in axial virtual cathode oscillator

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