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张涛, T. Zhang, D. T. K. Kwok and P. K. Chua, I. G. Brown
J. Appl. Phys. , Vol. 89, No. 1, 1 January 2001,-0001,():
-1年11月30日
A magnetic filter was inserted between the cathodic arc plasma source and chamber to reduce the amount of macroparticles transmitted from the plasma to the sample. The plasma output of the magnetic filter was determined as a function of magnetic field and bias voltage, for the cases when the bias was applied to the entire duct wall or to a Bilek bias plate alone. The factors affecting plasma diffusion in the duct were investigated. As well as collisional and inhomogeneous magnetic field effects, our computer simulation and experimental results indicate that the E
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【期刊论文】Plasma transport in magnetic duct filter
张涛, Tao Zhang, , Paul K Chu, Ricky K Y Fu and Ian G Brown
J. Phys. D: Appl. Phys. 35(2002)3176-3180,-0001,():
-1年11月30日
A cathodic arc plasma source equipped with a curved magnetic duct to filter macro-particles was used to study plasma transport through the duct. The optimal duct bias, at which the magnetic duct produces the maximum plasma output, for titanium cathodic arc plasma at 50, 100 and 150A arc current was determined and the parametric effects of the arc current and guiding magnetic field on the optimal duct bias were investigated. The optimal bias decreased as the guiding magnetic field increased from 100 to 400G and was almost independent of the guiding magnetic field when it was between 400 and 600G, the upper limit for our equipment. The optimal duct bias at 400G guiding magnetic field decreased with increasing arc current. Our results indicate that the optimal duct bias is related not only to the structure of the plasma source, but is also influenced by many other factors including cathode material and other plasma properties.
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张涛, Tao Zhang, Paul K. Chua, Ian G. Brown
Appl. Phys. Lett. , Vol. 80, No. 20, 20 May 2002,-0001,():
-1年11月30日
A negatively biased collecting plate was used to collect the ion current of the cathodic arc plasma transported through a curved magnetic duct. The optimal duct bias at which the duct has the maximum efficiency for plasma transport was measured for C, Ti, Mo, and W plasmas as a function of the arc current and guiding magnetic field. The optimal bias decreased with the magnetic field and was almost steady when the field was above 400G. The optimal bias at 400G and above increased with the arc current for C plasma but the opposite relationship was observed for Ti, Mo, and W plasmas. The effects of the plasma density, ion mass, ion kinetic energy, and magnetic field on the optimal bias are discussed.
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【期刊论文】Wall sheath and optimal bias in magnetic filters for vacuum arc plasma sources
张涛, T. Zhang and Y. C. Zhang, P. K. Chub , I. G. Brown
Appl. Phys. Lett. , Vol. 80, No. 3, 21 January 2002,-0001,():
-1年11月30日
A plasma diffusion model is established to determine the optimal bias and sheath patterns in a positively biased magnetic filter of a metal arc plasma source. We determine the equation for the optimal bias on the magnetic filter. According to our model, the optimal bias is related to the electron speed, ion speed, ion mass, ion charge state, and plasma density in the filter. The optimal bias increases as these variables are increased with the exception of the electron speed. Even though the magnetic field is taken into account, it is not a variable in the final equation. Our experimental results confirm that the magnetic field has almost no influence on the optimal bias. An alternate design approach is suggested that should lead to enhanced plasma transport through the filter.
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【期刊论文】Effect of magnetic field of light on refractive index
张涛, Zhang Tao
Chinese Physics Vol. 13 No. 8 August 2004 1009-1963/2004/13(08)/1358-07,-0001,():
-1年11月30日
Light refraction in a medium results from energy exchange between the medium and the magnetic field of the light. Formulas of refractive index, that is, the ratio of light speed in vacuum to light speed in the medium, were derived with the inductor model of electron cloud and the law of energy conservation. Refractive indices of several media were calculated using the formulas derived, and the calculated results are in agreement with the results measured. The anisotropy and the nonlinearity of the refractive index are explained with the theory described in this work.
refractive index, light speed, medium
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