Effect of magnetic field in the ATON-type hall thruster buffer chamber on discharge current characteristics

Discriminated from the ionization in the discharge channel of the ATON-type hall thruster, the ionization in the buffer chamber, called ldquopre-ionizationrdquo, has an impact on the discharge current characteristics. To improve the pre-ionization ratio by optimizing magnetic field in the buffer chamber, the main characteristics of the magnetic field are proposed in this article; and then a new magnetic circuit is designed for realizing the optimized magnetic field in the buffer chamber, while the magnetic field in the discharge channel is hold in optimum topography. In addition, the new magnetic circuit configuration can reduce the energy loss for the ldquofast electronsrdquo coming from the discharge channel. The corresponding experimental results obtained indicate that the discharge current characteristics in the buffer are improved by the optimized magnetic field.