The Influences of the Magnetic Field Strength on the Magnetic Confinement of Primary Electrons in an Ion Source

This paper deals with the simulation of trajectories of energetic electrons under the influence of a multi-cusp magnetic field produced by a permanent magnet assembly in a ring cusp geometry which is designed for supporting a plasma based ion source. The primary electrons are assumed as being emitted from a cathode located coaxially with the cylindrical discharge chamber. The volume of the region occupied by the electron trajectories and the magnetic trapping time were evaluated and plots are presented showing the effects of the surface magnetic field strength of the magnets on the volume and the mean confinement time of primary electrons in the ion source.     

Magnetic confinement studies for performance enhancement of a 5-cmion thruster

Several magnet assemblies relevant to ion thrusters were investigated using a numerical code to calculate the primary electron mean containment time. An analytical model was used to determine, consistently with the plasma stability condition, the ion thruster performance parameters, namely, the plasma ion energy cost, the plasma density, the plasma potential, and the doubly charged ion production rate as a function of the propellant mass flow rate. The numerical code was checked by reproducing the experimental performance parameters obtained from a 7-m checkerboard ion thruster. Using this approach, performance curves were obtained for a 5-cm ion thruster devised to produce a 1-mN thrust with low power and propellant consumption