磁场方向对碳纳米管氢等离子体微波吸收的影响

摘要

深入研究了外加磁场的方向对碳纳米管薄膜中氢等离子体电磁波衰减性能的影响。根据磁离子理论和W．K．B半经典近似法，理论推导了外加静磁场方向和微波传播方向之间的夹角θ为任一值时，碳纳米管薄膜磁化氢等离子体的复介电常数和微波衰减吸收系数公式。在不同条件下数值计算了碳纳米管薄膜中磁化氢等离子体的微波衰减吸收随θ的变化关系。理论结果表明：只要适当调控磁场方向，应用外加静磁场能有效改进碳纳米管氢等离子体的微波衰减吸收性能。通过调节氢等离子体密度、电子有效碰撞频率、外加静磁场的强度和方向，能获得碳纳米管薄膜氢等离子体对某一特定频段微波能的强烈吸收。%The influences of external magnetic field direction on hydrogen plasma microwave attenuation absorption in carbon nanotubes have been investigated in depth.With magneto-ionic theory and W.K.B approximation,the formula of complex permittivity and mi-crowave attenuation coefficients in magnetized hydrogen plasma carbon nanotubes film has been deduced at an arbitrary angle θof the external static background magnetic field direction with respect to incident wave propagation.The microwave attenuation coefficients of hydrogen plasma in CNTs film are calculated via θunder different conditions.Theoretical results show that the application of a static background magnetic field can effectively improve microwave attenuation absorption properties of hydrogen plasma in carbon nanotubes as long as the magnetic field direction is adjusted appropriately.The specified frequency of microwave can be intensively absorbed by the hydrogen plasma in carbon nanotubes through adjusting the density of the hydrogen plasma,the electronic effective collision fre-quency,the intensity and direction of the external magnetic field.