경희대학교 BK21

아래와 같이 세미나를 진행하오니
관심있는 분들의 많은 참여를 바랍니다.

-------------------- 아 래 --------------------

● 날짜 : 2014년 12월 9일 (화요일)
● 시간 : 16시 30분
● 장소 : 천문대 영상실
● 강사 : Prof. C. Z. Cheng - Institute of Space and Plasma Sciences, National Cheng Kung University, Taiwan
● 주제 : Physical Processes of Driven Magnetic Reconnection in Collisionless Plasmas (Zero Guide Field Case)

 

Abstract

  The physical pictures of electron and ion dynamics, how the electric and magnetic fields evolve, and how particles gain energy are presented for the driven magnetic reconnection in collisionless plasmas for the case of zero external guide field. The key kinetic physics is the decoupling of electron and ion dynamics when the spatial scale lengths of the electric field and magnetic field are comparable to or smaller than the particle gyroradii or when the particle orbit is meandering in the magnetic field reversal region. Because of the difference in the electron and ion gyroradii or meandering orbit widths, the kinetic effect causes charge separation to produce the in-plane electrostatic electric field, which is perpendicular to both the magnetic field and the inductive electric field. Because the electron outflow velocity dominates over the ion outflow velocity in the reconnection exhaust, a pair of currents flowing inward toward the reconnection current layer are produced to generate the quadrupole out-of-plane magnetic field, which is concentrated around the separatrix region. Then, the inductive electric field has components perpendicular and parallel to the magnetic field. We will discuss the electron and ion dynamics and how particle flow and gain energy under the influence of the electrostatic and inductive electric fields in the magnetic reconnection field geometry.