scholarly journals The Dielectric Wall Accelerator

2009 ◽  
Vol 02 (01) ◽  
pp. 253-263 ◽  
Author(s):  
George J. Caporaso ◽  
Yu-Jiuan Chen ◽  
Stephen E. Sampayan
Keyword(s):  
Electric Field ◽  
Traveling Wave ◽  
Tube Wall ◽  
Mass Ratio ◽  
Dielectric Wall ◽  
Beam Tube ◽  
Surface Flashover ◽  
Key Technologies ◽  
Tangential Electric Field ◽  
Accelerator Architectures

Dielectric wall accelerators, a class of induction accelerators, employ a novel insulating beam tube to impress a longitudinal electric field on a bunch of charged particles. The surface flashover characteristics of this tube may permit the attainment of accelerating gradients on the order of 100 MV/m for accelerating pulses on the order of a nanosecond in duration. A virtual traveling wave of excitation along the tube is produced at any desired speed by controlling the timing of pulse-generating modules that supply a tangential electric field to the tube wall. Because of the ability to control the speed of this virtual wave, the accelerator is capable of handling any charge-to-mass-ratio particle; hence it can be used for electrons, protons and any ion. The accelerator architectures, key technologies and development challenges will be described.

scholarly journals Restraining Surface Charge Accumulation and Enhancing Surface Flashover Voltage through Dielectric Coating

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 750
Author(s):  
Jixing Sun ◽  
Sibo Song ◽  
Xiyu Li ◽  
Yunlong Lv ◽  
Jiayi Ren ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Electric Field ◽  
Electric Fields ◽  
Transition Process ◽  
Metallic Particle ◽  
Particle Charging ◽  
Insulating Surfaces ◽  
Surface Flashover ◽  
Charging Time ◽  
The Impact

A conductive metallic particle in a gas-insulated metal-enclosed system can charge through conduction or induction and move between electrodes or on insulating surfaces, which may lead to breakdown and flashover. The charge on the metallic particle and the charging time vary depending on the spatial electric field intensity, the particle shape, and the electrode surface coating. The charged metallic particle can move between the electrodes under the influence of the spatial electric field, and it can discharge and become electrically conductive when colliding with the electrodes, thus changing its charge. This process and its factors are mainly affected by the coating condition of the colliding electrode. In addition, the interface characteristics affect the particle when it is near the insulator. The charge transition process also changes due to the electric field strength and the particle charging state. This paper explores the impact of the coating material on particle charging characteristics, movement, and discharge. Particle charging, movement, and charge transfer in DC, AC, and superimposed electric fields are summarized. Furthermore, the effects of conductive particles on discharge characteristics are compared between coated and bare electrodes. The reviewed studies demonstrate that the coating can effectively reduce particle charge and thus the probability of discharge. The presented research results can provide theoretical support and data for studying charge transfer theory and design optimization in a gas-insulated system.

scholarly journals Charging of Piezoelectric Cellular Polypropylene Film by Means of a Series Dielectric Layer

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 333
Author(s):  
Pedro Llovera-Segovia ◽  
Gustavo Ortega-Braña ◽  
Vicente Fuster-Roig ◽  
Alfredo Quijano-López
Keyword(s):  
Electric Field ◽  
Corona Discharge ◽  
Dielectric Layer ◽  
Dielectric Breakdown ◽  
Piezoelectric Materials ◽  
High Resistivity ◽  
Internal Electric Field ◽  
Dielectric Polarization ◽  
Surface Flashover ◽  
In Series

Piezoelectric polymer cellular films have been developed and improved in the past decades. These piezoelectric materials are based on the polarization of the internal cells by means of induced discharges in the gas inside the cells. Internal discharges are driven by an external applied electric field. With this polarization method, cellular polypropylene (PP) polymers exhibit a high piezoelectric coefficient d33 and have been investigated because of their low dielectric polarization, high resistivity, and flexibility. Charging polymers foams is normally obtained by applying a corona discharge to the surface with a single tip electrode-plane arrangement or a triode electrode, which consists of a tip electrode-plane structure with a controlled potential intermediate mesh. Corona charging allows the surface potential of the sample to rise without breakdown or surface flashover. A charging method has been developed without corona discharge, and this has provided good results. In our work, a method has been developed to polarize polypropylene foams by applying an insulated high-voltage electrode on the surface of the sample. The dielectric layer in series with the sample allows for a high internal electric field to be reached in the sample but avoids dielectric breakdown of the sample. The distribution of the electric field between the sample and the dielectric barrier has been calculated. Experimental results with three different electrodes present good outcome in agreement with the calculations. High d33 constants of about 880 pC/N have been obtained. Mapping of the d33 constant on the surface has also been carried out showing good homogeneity on the area under the electrode.

The Design and Implementation of Ship Electric Field Measurement System Based on MSP430

2012 ◽  
Vol 622-623 ◽  
pp. 1378-1383
Author(s):  
Peng Han ◽  
Yang Li
Keyword(s):  
Electric Field ◽  
Measurement System ◽  
Field Measurement ◽  
High Accuracy ◽  
Low Power Consumption ◽  
Electric Field Measurement ◽  
Low Snr ◽  
Design And Implementation ◽  
Key Technologies ◽  
Software And Hardware

The ship electric field has become a new physical field which is widely concerned at home and abroad in recent years. For the research of ship electric field, one of the most effective methods is to measure it underwater. According to the analysis of ship electric field signal’s characteristics, the ship electric field measurement system based on MSP430F149 was designed and the key technologies of software and hardware were also presented in this paper. The results of experiment demonstrated that the system could effectively measure the ship electric field signal in a low SNR. Meanwhile, it has the advantages of low power consumption, high accuracy and credible.

The Optimum Design of Traveling-Wave Electroosmotic Micropumps

2009 ◽  
Author(s):  
Shou-Ping Hsu ◽  
Hong-Jun Ye ◽  
Win-Jet Luo ◽  
Jauh-Shyong Chen
Keyword(s):  
Electric Field ◽  
Optimum Design ◽  
Double Layer ◽  
Traveling Wave ◽  
Microelectrode Arrays ◽  
Operating Frequency ◽  
Optimum Operating ◽  
Gap Size ◽  
Wave Potential

This study investigates the performace of electroosmotic micropumps with arrays of microelectrodes for pumping electrolyte in a microchannel. Traveling-wave potentials are applied to the microelectrode arrays. Ions accumulate in the double layer in response to the applied signal. The electric field acts on the charge pulling the fluid in the direction of the traveling wave. In this study, the effects of the widths and heights of the electrodes, the gap size between the electrodes and the frequency of the applied traveling-wave potential on the pumping velocity of the micropump are investigated in order to obtain the optimum design of the micropump. The optimum operating frequency of the traveling-wave potential is about 1 kHz for the micropumps with different electrode widths and gap sizes. The pumping velocities increase with the decrease of the electrode widths and gap sizes for the micropumps. For the micropumps with different electrode widths and gap sizes, it is found the optimum electrode heights are about 5.5 μm when the gap sizes are less than the electrode widths, and the optimum electrode heights are about 10.4 μm when the gap sizes are greater than the electrode widths.

Study on Discharge of Separated Water Droplets in DC Field

2011 ◽  
Vol 130-134 ◽  
pp. 3276-3279
Author(s):  
Zong Xi Zhang ◽  
Shan Feng Yin
Keyword(s):  
Electric Field ◽  
Hydrophobic Surface ◽  
Electrical Equipment ◽  
Water Droplets ◽  
Surface Flashover ◽  
Voltage Drops ◽  
Flashover Voltage ◽  
Dc Electric Field ◽  
Water Drops ◽  
And Migration

With the accelerating construction of strong smart grid, and the grid voltage level rising, performance requirements for the electrical insulation of electrical equipment also continue to increase. In terms of the advantages of RTV on antifouling, RTV-based paints coated insulator coating capacity of its flash tolerance can significantly increase, mainly due to RTV coating hydrophobic hydrophobicity and migration. But when the hydrophobic surface is in the fully wet, many small drops of water in the surface will be gathered into big drops of water, and these large droplets will distort the surface electric field of the medium. So the flashover voltage of the hydrophobic surface’s separated water droplets under DC electric field are analyzed comparatively in this paper, while some influencing factors such as different medias and volume of water drops, are introduced in specific experiments, and their effects on the flashover voltage are analyzed; under DC electric field experiment on the surface of hydrophobic and hydrophilic surface flashover voltage drops separation characteristics were studied.

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