Magnetoelectric heating was used to heat ions in an ECR plasma with a magnetic mirror field.The temperature and density of ions were measured by an ion sensitive probe（ISP） before and after magnetoelectric heating i...Magnetoelectric heating was used to heat ions in an ECR plasma with a magnetic mirror field.The temperature and density of ions were measured by an ion sensitive probe（ISP） before and after magnetoelectric heating in order to investigate the influence of the anode ring’s radius,axial position and working pressure on magnetoelectric heating.Results showed that a suitable radius of the anode ring could improve the ion temperature effectively and the optimal size of the anode ring depended on the cyclotron radius of ions.The radial uniformity of the ion density was improved by increasing the radius of the anode ring after heating.The magnetic mirror field could reduce the loss of ions caused by collision with the wall of the chamber and it was beneficial to increase the ion temperature and the ion density.It was suitable to heat the ions when the anode ring was set at the center of the magnetic mirror field where there was a weaker magnetic field strength.Lower pressure contributed to the increase in the ion temperature and efficiency of magnetoelectric heating.展开更多
Ion parameters in electron cyclotron resonance （ECR） microwave plasma were measured by ion sensitive probe and were compared with the electron parameters obtained by double Langmuir probe. The effects of gas pressur...Ion parameters in electron cyclotron resonance （ECR） microwave plasma were measured by ion sensitive probe and were compared with the electron parameters obtained by double Langmuir probe. The effects of gas pressure and microwave power on the ion temperature and density were analyzed. The spatial distribution of the ion parameters was also investigated by the ion sensitive probes with a tunable radial depth installed on different probe windows along the chamber axis. Results showed that the ion density measured by the ion sensitive probe was in good agreement with the electron density measured by the double Langmuir probe. The influ- ence of gas pressure on the ion parameters was stronger than that of microwave power. With the increase in working pressure, the ion temperature decreased monotonously with a decreasing rate larger than that at higher pressure. The ion density first increased to a peak （42.3~ 101~ cm-3） at 1 Pa and then decreased. The ion temperature and density increased little with the increase in the microwave power from 400 W to 800 W, The plasma far away from the resonant point is found to be radially uniform.展开更多
In order to precisely measure the ion parameters in a microwave electron cyclotron resonance plasma using an ion sensitive probe,the dependences of the current-voltage（I-V）characteristics on the shielding height（h...In order to precisely measure the ion parameters in a microwave electron cyclotron resonance plasma using an ion sensitive probe,the dependences of the current-voltage（I-V）characteristics on the shielding height（h）and the potential difference between inner and outer electrodes（V_B）have been investigated at different working pressures of 0.03 Pa and 0.8 Pa.Results show that the I-V curves at higher pressure are more sensitive to the variation of h than those at lower pressure.The influence of V_B on ion temperature（T_i）measurement becomes more prominent when the pressure is increased from 0.03 Pa to 0.8 Pa.Under both pressures,the optimized h is obtained at the condition where the current reaches zero in the positive voltage region with a suitable V_B of-1.5 V because of effective shielding of the electron E×B drift.展开更多
基金supported by National Natural Science Foundation of China(No.10875093)
文摘Magnetoelectric heating was used to heat ions in an ECR plasma with a magnetic mirror field.The temperature and density of ions were measured by an ion sensitive probe（ISP） before and after magnetoelectric heating in order to investigate the influence of the anode ring’s radius,axial position and working pressure on magnetoelectric heating.Results showed that a suitable radius of the anode ring could improve the ion temperature effectively and the optimal size of the anode ring depended on the cyclotron radius of ions.The radial uniformity of the ion density was improved by increasing the radius of the anode ring after heating.The magnetic mirror field could reduce the loss of ions caused by collision with the wall of the chamber and it was beneficial to increase the ion temperature and the ion density.It was suitable to heat the ions when the anode ring was set at the center of the magnetic mirror field where there was a weaker magnetic field strength.Lower pressure contributed to the increase in the ion temperature and efficiency of magnetoelectric heating.
基金supported by National Natural Science Foundation of China (No. 10875093)
文摘Ion parameters in electron cyclotron resonance （ECR） microwave plasma were measured by ion sensitive probe and were compared with the electron parameters obtained by double Langmuir probe. The effects of gas pressure and microwave power on the ion temperature and density were analyzed. The spatial distribution of the ion parameters was also investigated by the ion sensitive probes with a tunable radial depth installed on different probe windows along the chamber axis. Results showed that the ion density measured by the ion sensitive probe was in good agreement with the electron density measured by the double Langmuir probe. The influ- ence of gas pressure on the ion parameters was stronger than that of microwave power. With the increase in working pressure, the ion temperature decreased monotonously with a decreasing rate larger than that at higher pressure. The ion density first increased to a peak （42.3~ 101~ cm-3） at 1 Pa and then decreased. The ion temperature and density increased little with the increase in the microwave power from 400 W to 800 W, The plasma far away from the resonant point is found to be radially uniform.
基金supported by National Natural Science Foundation of China(No.10875093)
文摘In order to precisely measure the ion parameters in a microwave electron cyclotron resonance plasma using an ion sensitive probe,the dependences of the current-voltage（I-V）characteristics on the shielding height（h）and the potential difference between inner and outer electrodes（V_B）have been investigated at different working pressures of 0.03 Pa and 0.8 Pa.Results show that the I-V curves at higher pressure are more sensitive to the variation of h than those at lower pressure.The influence of V_B on ion temperature（T_i）measurement becomes more prominent when the pressure is increased from 0.03 Pa to 0.8 Pa.Under both pressures,the optimized h is obtained at the condition where the current reaches zero in the positive voltage region with a suitable V_B of-1.5 V because of effective shielding of the electron E×B drift.
