A self-consistent fluid model is developed to investigate the radial distributions of dusty plasma parameters in a DC glow discharge,in which the extended fluid approach of plasma particles and the transport equations...A self-consistent fluid model is developed to investigate the radial distributions of dusty plasma parameters in a DC glow discharge,in which the extended fluid approach of plasma particles and the transport equations of dust particles are coupled.The electrical interaction between charged dust particles is considered in the model.The time evolution of radial distributions of dust density,plasma density,the radial component of electric field and the forces acting on dust particles when dust density tends to be stable,are obtained and analyzed under different discharge currents and dust particle radii.It is shown that the dust density structure is determined mainly by the radial electrostatic force,thermophoretic force and ion drag force in the discharge tube,and both discharge current and dust particle radius have an obvious effect on the transport processes of dust particles.The dust particles gather in the central region of the discharge tube for low discharge current and small dust radius,then dust voids are formed and become wider when the discharge current and dust radius increase.The plasma parameters in the dust gathering region are obviously affected by the dust particles due to the charging processes of electrons and ions to the dust surface.展开更多
Measurements of dust plasma parameters were carried out in the discharges of (SiH 4 /C 2 H 4 /Ar) mixtures. Dust particles were formed in the capacitively coupled radio-frequency discharge of these reactive mixtures i...Measurements of dust plasma parameters were carried out in the discharges of (SiH 4 /C 2 H 4 /Ar) mixtures. Dust particles were formed in the capacitively coupled radio-frequency discharge of these reactive mixtures in a cylindrical chamber. Langmuir probe was employed for diagnosing and measuring the important plasma parameters such as electron density and electron temperature. The results showed that the electron density dropped, and in contrast the electron temperature rose when the dust particles formed. The curves of the electron density and temperature versus the RF power and pressure were presented and analysed. Further, it was found that the variations of electron temperature and the size of dust void with the RF power followed the similar trends. These trends might be useful for understanding more about the characteristics of dusty voids.展开更多
Voids and complex cloud patterns have been observed in a radio frequency (rf) discharge dusty plasma system. The structures and behaviors of these patterns were investigated in two- and three-dimensions by shifting an...Voids and complex cloud patterns have been observed in a radio frequency (rf) discharge dusty plasma system. The structures and behaviors of these patterns were investigated in two- and three-dimensions by shifting an il- lumination laser sheet beam up and down. Two-dimensional (2D) circular voids, thin ring voids, and their coexistent voids were observed at the early stage of particle growth. The cor- responding three-dimensional (3D) structures were dome, shell, and their coexistent voids, respectively. The complex fluid-like cloud patterns occurred above the 3D dome voids. The origin and evolution process of the complex dust cloud patterns need a further theoretical explanation.展开更多
基金supported by the Stable-Support Scientific Project of China Research Institute of Radiowave Propagation(No.132101W07)National Natural Science Foundation of China(No.12105251)National Key Laboratory Foundation Electromagnetic Environment(Nos.A382101001,A382101002 and A152101731-C02).
文摘A self-consistent fluid model is developed to investigate the radial distributions of dusty plasma parameters in a DC glow discharge,in which the extended fluid approach of plasma particles and the transport equations of dust particles are coupled.The electrical interaction between charged dust particles is considered in the model.The time evolution of radial distributions of dust density,plasma density,the radial component of electric field and the forces acting on dust particles when dust density tends to be stable,are obtained and analyzed under different discharge currents and dust particle radii.It is shown that the dust density structure is determined mainly by the radial electrostatic force,thermophoretic force and ion drag force in the discharge tube,and both discharge current and dust particle radius have an obvious effect on the transport processes of dust particles.The dust particles gather in the central region of the discharge tube for low discharge current and small dust radius,then dust voids are formed and become wider when the discharge current and dust radius increase.The plasma parameters in the dust gathering region are obviously affected by the dust particles due to the charging processes of electrons and ions to the dust surface.
基金supported by the National Natural Science Foundation of China (Grant Nos 10505005 and 10775026)
文摘Measurements of dust plasma parameters were carried out in the discharges of (SiH 4 /C 2 H 4 /Ar) mixtures. Dust particles were formed in the capacitively coupled radio-frequency discharge of these reactive mixtures in a cylindrical chamber. Langmuir probe was employed for diagnosing and measuring the important plasma parameters such as electron density and electron temperature. The results showed that the electron density dropped, and in contrast the electron temperature rose when the dust particles formed. The curves of the electron density and temperature versus the RF power and pressure were presented and analysed. Further, it was found that the variations of electron temperature and the size of dust void with the RF power followed the similar trends. These trends might be useful for understanding more about the characteristics of dusty voids.
文摘Voids and complex cloud patterns have been observed in a radio frequency (rf) discharge dusty plasma system. The structures and behaviors of these patterns were investigated in two- and three-dimensions by shifting an il- lumination laser sheet beam up and down. Two-dimensional (2D) circular voids, thin ring voids, and their coexistent voids were observed at the early stage of particle growth. The cor- responding three-dimensional (3D) structures were dome, shell, and their coexistent voids, respectively. The complex fluid-like cloud patterns occurred above the 3D dome voids. The origin and evolution process of the complex dust cloud patterns need a further theoretical explanation.
