报告题目：MHD waves in ionisation non-equilibrium plasmas 

　　报告人：Istvan Ballai博士(The University of Sheffield, UK) 

　　摘要：Many space plasmas are in a partially ionised state,where neutrals, heavy ions and electrons are treated as a separate fluids, however they behave in a collective manner.Usually the standard theory considers that the plasma is in 　　ionisation equilibrium, i.e. the rates of ionisation and recombination are equal and collisions occurring in the plasma are always elastic However this is an idealistic 　　restriction, the two rates are not always equal and a different approach is needed. In my presentation I will consider the ionisation non-equilibrium of plasmas (with 　　special emphasis on solar prominences) due to inelastic collisions and construct the rate equation for the excited of atoms and ion/electrons. Assuming a simple form for the ionisation and excitation rate, I will discuss briefly what changes such considerations will bring into the equations describing the nature of magnetic and magnetoacoustic waves. 

　　时间：2015年10月30日（周五）15:30pm 

　　地点：天文楼402会议室