Condition for charged particle trapping in a three-dimensional electrostatic potential well in the presence of a magnetic field

摘要

Charged particle dynamics in a superimposed axially symmetric electrostatic potential well and a uniform magnetic field is studied within the framework of adiabatic theory. An approximate expression for the adiabatic invariant of the motion is derived. The condition for particle trapping in the potential well is established by taking into account finite gyroradius effects.