In a pulsed vacuum discharge,the ejection performance of a metal plasma jet can be effectively improved by preventing charged particles from moving to the anode.In this paper,the effects of resistance and capacitance ...In a pulsed vacuum discharge,the ejection performance of a metal plasma jet can be effectively improved by preventing charged particles from moving to the anode.In this paper,the effects of resistance and capacitance on the anode side on the discharge characteristics and the generation characteristics of plasma jet are investigated.Results show that the existence of a resistor on the anode side can increase the anode potential,thereby preventing charged particles from entering the anode and promoting the ejection of charged particles along the axis of the insulating sleeve nozzle.The application of a capacitor on the anode side can not only absorb electrons at the initial stage of discharge,increasing the peak value of the cathode hump potential,but also prevent charged particles from moving to the anode,thereby improving the ejection performance of the plasma jet.In addition,the use of a larger resistance and a smaller capacitance can improve the blocking effect on charged particles and further improve the ejection performance of the plasma jet.Results of this study will provide a reference for the improvement of the ejection performance of plasma jets and their applications.展开更多
The thermionic vacuum arc （TVA） is a new type of plasma source, which generates a pure metal and ceramic vapour plasma containing ions with a directed energy. TVA discharges can be ignited in high vacuum conditions ...The thermionic vacuum arc （TVA） is a new type of plasma source, which generates a pure metal and ceramic vapour plasma containing ions with a directed energy. TVA discharges can be ignited in high vacuum conditions between a heated cathode （electron gun） and an anode （tungsten crucible） containing the material. The accelerated electron beam, incident on the anode, heats the crucible, together with its contents, to a high temperature. After establishing a steadystate density of the evaporating anode material atoms, and when the voltage applied is high enough, a bright discharge is ignited between the electrodes. We generated silver and Al2O3 TVA discharges in order to compare the metal and ceramic TVA discharges. The electrical and optical characteristics of silver and Al2O3 TVA discharges were analysed. The TVA is also a new technique for the deposition of thin films. The film condenses on the sample from the plasma state of the vapour phase of the anode material, generated by a TVA. We deposited silver and Al2O3 thin films onto an aluminium substrate layer-by-layer using their TVA discharges, and produced micro and/or nano-layer Ag-Al2O3 composite samples. The composite samples using scanning electron microscopy was also analysed.展开更多
Titanium deuteride is an important nuclear material used in the field of nuclear technology, and further research is needed into TiD2 films irradiated by pulsed ion beams of the vacuum arc discharge with hydrogen. In ...Titanium deuteride is an important nuclear material used in the field of nuclear technology, and further research is needed into TiD2 films irradiated by pulsed ion beams of the vacuum arc discharge with hydrogen. In the current study, these irradiated TiD2 films have been investigated using scanning electronic microscopy and slow positron annihilation techniques. Both the thermal effect and irradiation defects of TiD2 films were studied, following their irradiation with mixed pulsed ion beams of titanium and hydrogen ions. It is found that the thermal effect is trivial on the irradiated surfaces, and the dominant effect is irradiation defects which can be enhanced by repetitive shots and is characterized by the inner diffusion of irradiation defects.展开更多
基金supported by the Fundamental Research Funds for the Central Universities(No.2019YJS187)National Natural Science Foundation of China(No.51577011)。
文摘In a pulsed vacuum discharge,the ejection performance of a metal plasma jet can be effectively improved by preventing charged particles from moving to the anode.In this paper,the effects of resistance and capacitance on the anode side on the discharge characteristics and the generation characteristics of plasma jet are investigated.Results show that the existence of a resistor on the anode side can increase the anode potential,thereby preventing charged particles from entering the anode and promoting the ejection of charged particles along the axis of the insulating sleeve nozzle.The application of a capacitor on the anode side can not only absorb electrons at the initial stage of discharge,increasing the peak value of the cathode hump potential,but also prevent charged particles from moving to the anode,thereby improving the ejection performance of the plasma jet.In addition,the use of a larger resistance and a smaller capacitance can improve the blocking effect on charged particles and further improve the ejection performance of the plasma jet.Results of this study will provide a reference for the improvement of the ejection performance of plasma jets and their applications.
基金supported by the Eskisehir Osmangazi University project(200319009)
文摘The thermionic vacuum arc （TVA） is a new type of plasma source, which generates a pure metal and ceramic vapour plasma containing ions with a directed energy. TVA discharges can be ignited in high vacuum conditions between a heated cathode （electron gun） and an anode （tungsten crucible） containing the material. The accelerated electron beam, incident on the anode, heats the crucible, together with its contents, to a high temperature. After establishing a steadystate density of the evaporating anode material atoms, and when the voltage applied is high enough, a bright discharge is ignited between the electrodes. We generated silver and Al2O3 TVA discharges in order to compare the metal and ceramic TVA discharges. The electrical and optical characteristics of silver and Al2O3 TVA discharges were analysed. The TVA is also a new technique for the deposition of thin films. The film condenses on the sample from the plasma state of the vapour phase of the anode material, generated by a TVA. We deposited silver and Al2O3 thin films onto an aluminium substrate layer-by-layer using their TVA discharges, and produced micro and/or nano-layer Ag-Al2O3 composite samples. The composite samples using scanning electron microscopy was also analysed.
文摘Titanium deuteride is an important nuclear material used in the field of nuclear technology, and further research is needed into TiD2 films irradiated by pulsed ion beams of the vacuum arc discharge with hydrogen. In the current study, these irradiated TiD2 films have been investigated using scanning electronic microscopy and slow positron annihilation techniques. Both the thermal effect and irradiation defects of TiD2 films were studied, following their irradiation with mixed pulsed ion beams of titanium and hydrogen ions. It is found that the thermal effect is trivial on the irradiated surfaces, and the dominant effect is irradiation defects which can be enhanced by repetitive shots and is characterized by the inner diffusion of irradiation defects.
