A method is presented to express the electrical parameters of the vacuum vessel in this paper. According to the results of numerical computation and the distribution of the eddy currents, the mutual inductance can be ...A method is presented to express the electrical parameters of the vacuum vessel in this paper. According to the results of numerical computation and the distribution of the eddy currents, the mutual inductance can be given by calculating the flux produced by the toroidal eddy currents. The time constants of the vacuum vessel of HT-7U tokamak are derived from the decay characteristics of the eddy currents.展开更多
A dielectric barrier discharge（DBD） reactor is introduced to generate H2O2 by non-thermal plasma with a mixture of oxygen and water mist produced by an ultrasonic atomizer.The results of our experiment show that the...A dielectric barrier discharge（DBD） reactor is introduced to generate H2O2 by non-thermal plasma with a mixture of oxygen and water mist produced by an ultrasonic atomizer.The results of our experiment show that the energy yield and concentration of the generated H2O2 in the pulsed discharge are much higher than that in AC discharge,due to its high energy efficiency and low heating effect.Micron-sized liquid droplets produced by an ultrasonic atomizer in water mist have large specific surface area,which greatly reduces mass transfer resistance between hydroxyl radicals and water liquids,leading to higher energy yield and H2O2 concentration than in our previous research.The influence of applied voltage,discharge frequency,and environmental temperature on the generated H2O2 is discussed in detail from the viewpoint of the DBD mechanism.The H2O2 concentration of 30 mg l^-1,with the energy yield of 2 gkW^-1h^-1 is obtained by pulsed discharge in our research.展开更多
The power supply system of ion source for the Neutral Beam Injector (NBI) in the HT-7 superconducting tokamak is based on a single injector with one ion source that can deliver 700 kW of neutral beam power. Experiment...The power supply system of ion source for the Neutral Beam Injector (NBI) in the HT-7 superconducting tokamak is based on a single injector with one ion source that can deliver 700 kW of neutral beam power. Experiments and a discharges test on the ion source were successfully performed. In this paper, the circuit structures and features of every power supply are described and the results of the discharges test are presented.展开更多
Molecular dynamics simulation of a sympathetically-cooled ^(113)Cd^(+)ion crystal system is achieved.Moreover,the relationship between ions’axial temperature and different electric parameters,including radio frequenc...Molecular dynamics simulation of a sympathetically-cooled ^(113)Cd^(+)ion crystal system is achieved.Moreover,the relationship between ions’axial temperature and different electric parameters,including radio frequency voltage and endcap voltage is depicted.Under stable trapping condition,optimum radio frequency voltage,corresponding to minimum temperature and the highest cooling efficiency,is obtained.The temperature is positively correlated with end-cap voltage.The relationship is also confirmed by a sympathetically-cooled ^(113)Cd^(+) microwave clock.The pseudo-potential model is used to illustrate the relationship and influence mechanism.A reasonable index,indicating ions’temperature,is proposed to quickly estimate the relative ions’temperature.The investigation is helpful for ion crystal investigation,such as spatial configuration manipulation,sympathetic cooling efficiency enhancement,and temporal evolution.展开更多
The impact of carbon doping on the background carrier conduction in GaN has been investigated.It is found that the incorporation of carbon can effectively suppress the n-type background carrier concentration as expect...The impact of carbon doping on the background carrier conduction in GaN has been investigated.It is found that the incorporation of carbon can effectively suppress the n-type background carrier concentration as expected.Moreover,from the fitting of the temperature-dependent carrier concentration and mobility,it is observed that high nitrogen-vacancy(VN)dominates the background carrier at room temperature which consequently results in n-type conduction.The doping agent(carbon atom)occupies the nitrogen site of GaN and forms CN deep acceptor as revealed from photoluminescence.Besides,a relatively low hole concentration is ionized at room temperature which was insufficient for the compensation of n-type background carriers.Therefore,we concluded that this background carrier concentration can be suppressed by carbon doping,which substitutes the N site of GaN and finally decreases the VN.展开更多
文摘A method is presented to express the electrical parameters of the vacuum vessel in this paper. According to the results of numerical computation and the distribution of the eddy currents, the mutual inductance can be given by calculating the flux produced by the toroidal eddy currents. The time constants of the vacuum vessel of HT-7U tokamak are derived from the decay characteristics of the eddy currents.
文摘A dielectric barrier discharge（DBD） reactor is introduced to generate H2O2 by non-thermal plasma with a mixture of oxygen and water mist produced by an ultrasonic atomizer.The results of our experiment show that the energy yield and concentration of the generated H2O2 in the pulsed discharge are much higher than that in AC discharge,due to its high energy efficiency and low heating effect.Micron-sized liquid droplets produced by an ultrasonic atomizer in water mist have large specific surface area,which greatly reduces mass transfer resistance between hydroxyl radicals and water liquids,leading to higher energy yield and H2O2 concentration than in our previous research.The influence of applied voltage,discharge frequency,and environmental temperature on the generated H2O2 is discussed in detail from the viewpoint of the DBD mechanism.The H2O2 concentration of 30 mg l^-1,with the energy yield of 2 gkW^-1h^-1 is obtained by pulsed discharge in our research.
基金The project supported by the Chinese Academy of Sciences (No. SYKXD04)
文摘The power supply system of ion source for the Neutral Beam Injector (NBI) in the HT-7 superconducting tokamak is based on a single injector with one ion source that can deliver 700 kW of neutral beam power. Experiments and a discharges test on the ion source were successfully performed. In this paper, the circuit structures and features of every power supply are described and the results of the discharges test are presented.
基金Project supported by the Beijing Natural Science Foundation(Grant No.1202011)the Tsinghua University Initiative Scientific Research Program,the National Natural Science Foundation of China(Grant No.12073015)the National Key Research and Development Program of China(Grant No.2016YFA0302101).
文摘Molecular dynamics simulation of a sympathetically-cooled ^(113)Cd^(+)ion crystal system is achieved.Moreover,the relationship between ions’axial temperature and different electric parameters,including radio frequency voltage and endcap voltage is depicted.Under stable trapping condition,optimum radio frequency voltage,corresponding to minimum temperature and the highest cooling efficiency,is obtained.The temperature is positively correlated with end-cap voltage.The relationship is also confirmed by a sympathetically-cooled ^(113)Cd^(+) microwave clock.The pseudo-potential model is used to illustrate the relationship and influence mechanism.A reasonable index,indicating ions’temperature,is proposed to quickly estimate the relative ions’temperature.The investigation is helpful for ion crystal investigation,such as spatial configuration manipulation,sympathetic cooling efficiency enhancement,and temporal evolution.
基金supported by the National Key Research and Development Program of China(Grant No.2017YFB0402800)the Key Research and Development Program of Guangdong Province,China(Grant No.2020B010174003)+1 种基金the National Natural Science Foundation of China(Grant No.U1601210)the Natural Science Foundation of Guangdong Province,China(Grant No.2015A030312011)。
文摘The impact of carbon doping on the background carrier conduction in GaN has been investigated.It is found that the incorporation of carbon can effectively suppress the n-type background carrier concentration as expected.Moreover,from the fitting of the temperature-dependent carrier concentration and mobility,it is observed that high nitrogen-vacancy(VN)dominates the background carrier at room temperature which consequently results in n-type conduction.The doping agent(carbon atom)occupies the nitrogen site of GaN and forms CN deep acceptor as revealed from photoluminescence.Besides,a relatively low hole concentration is ionized at room temperature which was insufficient for the compensation of n-type background carriers.Therefore,we concluded that this background carrier concentration can be suppressed by carbon doping,which substitutes the N site of GaN and finally decreases the VN.
