Particle dynamics in the plasma sheet

摘要: Trajectories of charged particles in the trail region earth's magnetosphere are studied numerically using a model magnetic field. It is shown that both trapped and untrapped trajectories can be categorized into three groups two dimensionless parameters. One parameters ratio x z components The other plasma sheet thickness to particle gyroradius midplane. Previous trajectory studies incorporated our classification scheme which resolves number apparent contradictory conclusions among them. analyzed terms cross-tail displacement, displacement time, scattering final pitch angle, coefficient reflection off sheet. results used predict upper limit on energization during one neutral interaction. An understanding motions individual magnetotail an important first step collective dynamics as whole. A authors have attempted analytical solutions equations motion by various approximations. Among them Speiser [1965], Alexeev Kropotkin [ 1970], Sonnerup 1971 ] obtained approximate highly nonadiabatic limit. On hand, Stern Palmadesso [1975] [1977] adiabatic Other integrate motion, for example, [1967], Cowley [1971], Eastwood [1972], Pudovkin Tsyganenko [1973], Swift [1977]. However, due assumptions made their studies, each author dealt only with limited variety trajectories, therefore cannot generalized all conditions occur magentotail. In this paper, numerical analysis possible orbits presented. previous works new scheme, disagreements studies. makes use suggested overall morphology determined motion. 2. THE MODEL AND EQUATIONS OF MOTION To analyze sheet, we chose field given