We have inquired into a means to decrease the number of charged particles escaping from a loss cone of a magnetic mirror reactor as many as possible. We previously reported the way of installing a supplemental magneti...We have inquired into a means to decrease the number of charged particles escaping from a loss cone of a magnetic mirror reactor as many as possible. We previously reported the way of installing a supplemental magnetic mirror (which has a cyclotron heating space within) at the exit of a main magnetic bottle. The cyclotron heating space was set to increase a reflection-efficiency of the supplemental mirror. We could not suppress the loss of the escaping deuteron ions sufficiently even with a very long mirror and a very powerful electric field. Then, in this work we propose a new plan of installing another supplemental mirror besides the previous supplemental mirror. A new mirror is set perpendicularly to the center axis of the main bottle. By the addition of the perpendicular mirror, an efficiency of sending back of escaping deuteron ions is considerably theoretically improved. Also in the previous work, since we did not touch how to supply a high-frequency electric field to the cyclotron heating space, here we consider supplying it by an extraordinary-wave with a cyclotron frequency. It is mentioned that propagation of an extraordinary-wave with an electron cyclotron frequency depends on a magnetic field strength and density of escaping electrons.展开更多
We reported previously the idea to improve reflection-ability of a magnetic mirror by installing a cyclotron resonance space in the front part of the mirror. However, since the previous analysis was insufficient from ...We reported previously the idea to improve reflection-ability of a magnetic mirror by installing a cyclotron resonance space in the front part of the mirror. However, since the previous analysis was insufficient from the examination after that, we complement the following two things in this work: 1) A simpler procedure of design to make a supplemental magnetic mirror with the simplest magnetic configuration, compared with the procedure reported previously. 2) A peculiar characteristic arising only in reflection of a nonrelativistic charged particle (a deuteron ion).展开更多
Numerical simulation of the effect of the anode magnetic shielding on the magnetic field and ion beam in a cylindrical Hall thruster is presented. The results show that after the anode is shielded by the magnetic shie...Numerical simulation of the effect of the anode magnetic shielding on the magnetic field and ion beam in a cylindrical Hall thruster is presented. The results show that after the anode is shielded by the magnetic shield, the magnetic field lines near the anode surface are obviously convex curved, the ratio of the magnetic mirror is enhanced, the width of the positive magnetic field gradient becomes larger than that without the anode magnetic shielding, the radial magnetic field component is enhanced, and the discharge plasma turbulence is reduced as a result of keeping the original saddle field profile and the important role the other two saddle field profiles play in restricting electrons. The results of the particle in cell （PIC） numerical simulation show that both the ion number and the energy of the ion beam increase after the anode is shielded by the magnetic shield. In other words, the specific impulse of the cylindrical Hall thruster is enhanced.展开更多
Two variants of application of a transaxial mirror with stigmatic spatial time-of-flight focusing in the time-of-flight mass spectrometer have been considered. In the first variant, the transaxial mirror is used as an...Two variants of application of a transaxial mirror with stigmatic spatial time-of-flight focusing in the time-of-flight mass spectrometer have been considered. In the first variant, the transaxial mirror is used as an ion reflector in the ordinary scheme of the time-of-flight mass reflectron. In the second variant, the transaxial mirror simultaneously fulfills the function of the ion reflector and corrector of aberrations caused by the energy spread of ions in the package, formed by the ion source of the mass reflectron. The expressions defining the conditions of stigmatic spatial time-of-flight focusing in the transaxial mirror and the combined system consisting of an ion source and a mirror have been derived. The relationships between geometrical and electrical parameters of three- and four-electrode transaxial mirrors realizing these conditions have been obtained by numerical calculations.展开更多
采用水热法结合银镜反应制备出一系列不同Ag负载量(2.2%、4.0%、6.4%,w/w)改性的3D纳米网状结构Ag@Ti O2薄膜电极。利用电感耦合等离子体技术(ICP)、X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和X射线能谱(EDX)等表征手段测试所合...采用水热法结合银镜反应制备出一系列不同Ag负载量(2.2%、4.0%、6.4%,w/w)改性的3D纳米网状结构Ag@Ti O2薄膜电极。利用电感耦合等离子体技术(ICP)、X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和X射线能谱(EDX)等表征手段测试所合成材料的形貌及成分,实验结果表明Ag纳米颗粒可以成功沉积在Ti O2纳米线表面。电化学测试数据则表明,4.0%(w/w)负载量的Ag@Ti O2相比于未改性和其他负载量的Ti O2纳米线具有更好的倍率性能和更稳定的可逆容量。在50,100,200,400,800和1 200 m A·g^(-1)的电流密度条件下,该改性电极的放电容量可分别达到261.4,253.7,239.5,216.5,193.1和185.1 m Ah·g^(-1),在200 m A·g^(-1)下循环80次后容量保持率仍能达到99.8%。展开更多
文摘We have inquired into a means to decrease the number of charged particles escaping from a loss cone of a magnetic mirror reactor as many as possible. We previously reported the way of installing a supplemental magnetic mirror (which has a cyclotron heating space within) at the exit of a main magnetic bottle. The cyclotron heating space was set to increase a reflection-efficiency of the supplemental mirror. We could not suppress the loss of the escaping deuteron ions sufficiently even with a very long mirror and a very powerful electric field. Then, in this work we propose a new plan of installing another supplemental mirror besides the previous supplemental mirror. A new mirror is set perpendicularly to the center axis of the main bottle. By the addition of the perpendicular mirror, an efficiency of sending back of escaping deuteron ions is considerably theoretically improved. Also in the previous work, since we did not touch how to supply a high-frequency electric field to the cyclotron heating space, here we consider supplying it by an extraordinary-wave with a cyclotron frequency. It is mentioned that propagation of an extraordinary-wave with an electron cyclotron frequency depends on a magnetic field strength and density of escaping electrons.
文摘We reported previously the idea to improve reflection-ability of a magnetic mirror by installing a cyclotron resonance space in the front part of the mirror. However, since the previous analysis was insufficient from the examination after that, we complement the following two things in this work: 1) A simpler procedure of design to make a supplemental magnetic mirror with the simplest magnetic configuration, compared with the procedure reported previously. 2) A peculiar characteristic arising only in reflection of a nonrelativistic charged particle (a deuteron ion).
基金supported by National Natural Science Foundation of China (No. 10675040)College Scientific Research and Development Fund (No. C122009015) of China
文摘Numerical simulation of the effect of the anode magnetic shielding on the magnetic field and ion beam in a cylindrical Hall thruster is presented. The results show that after the anode is shielded by the magnetic shield, the magnetic field lines near the anode surface are obviously convex curved, the ratio of the magnetic mirror is enhanced, the width of the positive magnetic field gradient becomes larger than that without the anode magnetic shielding, the radial magnetic field component is enhanced, and the discharge plasma turbulence is reduced as a result of keeping the original saddle field profile and the important role the other two saddle field profiles play in restricting electrons. The results of the particle in cell （PIC） numerical simulation show that both the ion number and the energy of the ion beam increase after the anode is shielded by the magnetic shield. In other words, the specific impulse of the cylindrical Hall thruster is enhanced.
文摘Two variants of application of a transaxial mirror with stigmatic spatial time-of-flight focusing in the time-of-flight mass spectrometer have been considered. In the first variant, the transaxial mirror is used as an ion reflector in the ordinary scheme of the time-of-flight mass reflectron. In the second variant, the transaxial mirror simultaneously fulfills the function of the ion reflector and corrector of aberrations caused by the energy spread of ions in the package, formed by the ion source of the mass reflectron. The expressions defining the conditions of stigmatic spatial time-of-flight focusing in the transaxial mirror and the combined system consisting of an ion source and a mirror have been derived. The relationships between geometrical and electrical parameters of three- and four-electrode transaxial mirrors realizing these conditions have been obtained by numerical calculations.
文摘采用水热法结合银镜反应制备出一系列不同Ag负载量(2.2%、4.0%、6.4%,w/w)改性的3D纳米网状结构Ag@Ti O2薄膜电极。利用电感耦合等离子体技术(ICP)、X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和X射线能谱(EDX)等表征手段测试所合成材料的形貌及成分,实验结果表明Ag纳米颗粒可以成功沉积在Ti O2纳米线表面。电化学测试数据则表明,4.0%(w/w)负载量的Ag@Ti O2相比于未改性和其他负载量的Ti O2纳米线具有更好的倍率性能和更稳定的可逆容量。在50,100,200,400,800和1 200 m A·g^(-1)的电流密度条件下,该改性电极的放电容量可分别达到261.4,253.7,239.5,216.5,193.1和185.1 m Ah·g^(-1),在200 m A·g^(-1)下循环80次后容量保持率仍能达到99.8%。
