Non-transferred dc arc plasma generators are widely used in materials processing.They are generally considered steadily-operating devises.However,unsteady phenomena do exist in them, and may cause non-ideal effects in...Non-transferred dc arc plasma generators are widely used in materials processing.They are generally considered steadily-operating devises.However,unsteady phenomena do exist in them, and may cause non-ideal effects in processes which require high controllability and reproducibility. These unsteady phenomena can cause parameter fluctuations in the arc and the plasma jet,some of which have been studied in recent years.Several types and mechanisms of these phenomena have been identified.This paper reviews the research progress in this specific area,hoping to present a more complete picture of this subject.展开更多
This paper presents the concept of a Dielectric-lined Multiwave Cerenkov Generator producing high power millimeter waves, which has been investigated with a two and onehalf dimensional electromagnetic relativistic Par...This paper presents the concept of a Dielectric-lined Multiwave Cerenkov Generator producing high power millimeter waves, which has been investigated with a two and onehalf dimensional electromagnetic relativistic Particle-in-Cell (PIC) plasma simulation code. Themodified device can operate in a lower diode-voltage regime with much higher radiation efficiencyand slight downshift of operation frequency. There exist the optima for the permittivity of thedielectric liner and for the magnitude of the guiding magnetic field. The required intensity of theguiding field is reduced by the introduction of the liner. The enhanced propagation of the electronbeam is studied in the presence of the liner.展开更多
This paper presents the results of the development and creation of plasma-chemical reactors for mobile and stationary installations for the destruction and disposal of solid, liquid, gaseous and mixed medical waste ba...This paper presents the results of the development and creation of plasma-chemical reactors for mobile and stationary installations for the destruction and disposal of solid, liquid, gaseous and mixed medical waste based on the domestic plasma generator PUN-1, with air as the plasma-forming gas. The design and principle of operation of plasma-chemical reactors installed on mobile experimental and industrial plants “Plazmon-1,2,3”, as well as the main features of the plasma waste disposal process are described.展开更多
By analyzing the time evolution of artificial plasma cloud in the high altitude of atmospheric environment, we found that there are two zones, an exponential attenuation zone and a linearly attenuating zone, existing ...By analyzing the time evolution of artificial plasma cloud in the high altitude of atmospheric environment, we found that there are two zones, an exponential attenuation zone and a linearly attenuating zone, existing in the spatial distribution of electron density of the artificial plasma clouds. The plasma generator's particle flux density only contributes to the exponential attenuation zone, and has no effect on the linear attenuation zone The average electron density in the linear attenuation zone is about 10-5 of neutral particle density, and can diffuse over a wider area. The conclusion will supply some valuable references to the research of electromagnetic wave and artificial plasma interaction, the plasma invisibleness research of missile and special aerocraft, and the design of artificial plasma source.展开更多
This paper describes a long-term operation of the 2.45-GHz microwave proton source at Peking University. The DC proton beam of 50–55 mA with energy of 35 keV has been run for 306 hours continuously. Total beam availa...This paper describes a long-term operation of the 2.45-GHz microwave proton source at Peking University. The DC proton beam of 50–55 mA with energy of 35 keV has been run for 306 hours continuously. Total beam availability,defined as 35-keV beam-on time divided by elapsed time, is higher than 99%. Water cooling machine failures cause all the downtime, and no plasma generator failure or high voltage breakdown is observed. The longest uninterrupted run time is122 hours.展开更多
A finite-rate method is used to simulate the three-dimensional combustion process in a plasma generator with CH4 as the fuel. The simulation was run with RNG k-ε model to simulate turbulence, with eddy-dissipation-co...A finite-rate method is used to simulate the three-dimensional combustion process in a plasma generator with CH4 as the fuel. The simulation was run with RNG k-ε model to simulate turbulence, with eddy-dissipation-concept (EDC) model to simulate the combustion and with discrete ordinates model to simulate radiation. The numerical results show that the flow field characteristics and the parameter distributions are under the condition of rich fuels, and these results provide valuable information when optimizing the plasma generator design and organizing its flow fields.展开更多
A thermal analysis of characteristic parameters in the electrode-region for tubular plasma generators is developed. Results of calculation on temperature of electrodes, evaporation rate and erosion rate for different ...A thermal analysis of characteristic parameters in the electrode-region for tubular plasma generators is developed. Results of calculation on temperature of electrodes, evaporation rate and erosion rate for different electrode materials are presented as a function of arc current, pressure of arc chamber, width of arc root and velocity of water coolant. Some experimental data on electrode erosion in a tubular plasma generator is given. The effects of operating parameters on erosion rate are discussed in detail.展开更多
基金supported by the National Natural Science Fouadation of China(50836007,10921062)
文摘Non-transferred dc arc plasma generators are widely used in materials processing.They are generally considered steadily-operating devises.However,unsteady phenomena do exist in them, and may cause non-ideal effects in processes which require high controllability and reproducibility. These unsteady phenomena can cause parameter fluctuations in the arc and the plasma jet,some of which have been studied in recent years.Several types and mechanisms of these phenomena have been identified.This paper reviews the research progress in this specific area,hoping to present a more complete picture of this subject.
文摘This paper presents the concept of a Dielectric-lined Multiwave Cerenkov Generator producing high power millimeter waves, which has been investigated with a two and onehalf dimensional electromagnetic relativistic Particle-in-Cell (PIC) plasma simulation code. Themodified device can operate in a lower diode-voltage regime with much higher radiation efficiencyand slight downshift of operation frequency. There exist the optima for the permittivity of thedielectric liner and for the magnitude of the guiding magnetic field. The required intensity of theguiding field is reduced by the introduction of the liner. The enhanced propagation of the electronbeam is studied in the presence of the liner.
文摘This paper presents the results of the development and creation of plasma-chemical reactors for mobile and stationary installations for the destruction and disposal of solid, liquid, gaseous and mixed medical waste based on the domestic plasma generator PUN-1, with air as the plasma-forming gas. The design and principle of operation of plasma-chemical reactors installed on mobile experimental and industrial plants “Plazmon-1,2,3”, as well as the main features of the plasma waste disposal process are described.
基金The project supported by the National Nature Science Foundation of China(No.10135020)and 863 National High Technology Program on Inertial Confinement Fusion of China
文摘By analyzing the time evolution of artificial plasma cloud in the high altitude of atmospheric environment, we found that there are two zones, an exponential attenuation zone and a linearly attenuating zone, existing in the spatial distribution of electron density of the artificial plasma clouds. The plasma generator's particle flux density only contributes to the exponential attenuation zone, and has no effect on the linear attenuation zone The average electron density in the linear attenuation zone is about 10-5 of neutral particle density, and can diffuse over a wider area. The conclusion will supply some valuable references to the research of electromagnetic wave and artificial plasma interaction, the plasma invisibleness research of missile and special aerocraft, and the design of artificial plasma source.
基金Project supported by the National Basic Research Program of China(Grant No.2014CB845502)the National Natural Science Foundation of China(Grant No.91126004)
文摘This paper describes a long-term operation of the 2.45-GHz microwave proton source at Peking University. The DC proton beam of 50–55 mA with energy of 35 keV has been run for 306 hours continuously. Total beam availability,defined as 35-keV beam-on time divided by elapsed time, is higher than 99%. Water cooling machine failures cause all the downtime, and no plasma generator failure or high voltage breakdown is observed. The longest uninterrupted run time is122 hours.
文摘A finite-rate method is used to simulate the three-dimensional combustion process in a plasma generator with CH4 as the fuel. The simulation was run with RNG k-ε model to simulate turbulence, with eddy-dissipation-concept (EDC) model to simulate the combustion and with discrete ordinates model to simulate radiation. The numerical results show that the flow field characteristics and the parameter distributions are under the condition of rich fuels, and these results provide valuable information when optimizing the plasma generator design and organizing its flow fields.
文摘A thermal analysis of characteristic parameters in the electrode-region for tubular plasma generators is developed. Results of calculation on temperature of electrodes, evaporation rate and erosion rate for different electrode materials are presented as a function of arc current, pressure of arc chamber, width of arc root and velocity of water coolant. Some experimental data on electrode erosion in a tubular plasma generator is given. The effects of operating parameters on erosion rate are discussed in detail.
