抄録
Low power Hall thrusters with circular cross-sectional discharge chambers, named TCHT-series were investigated to obtain the performance characteristics and plasma features. Hall thrusters with circular cross-sectional discharge chambers will be suitable for low power Hall thrusters because of the large volume-to-surface ratio which suppresses overheating of inner magnetic coils and ion losses on the chamber wall. TCHT-2 achieved 25% of thrust efficiency in the input power range of 100–200W. From RPA and double probe measurements, it is expected that the ionization region is located near the anode in which strong radial magnetic field exists. The Hall thruster TCHT-3 is downsized thruster for lower power operation, and the effect of magnetic field profiles on thrust performance was examined. TCHT-3 were classified into TCHT-3A and TCHT-3B. The Hall thruster TCHT-3A has the similar magnetic field configuration to TCHT-2, and the peak of radial magnetic flux density is located near the anode. On the other hand, TCHT-3B has the peak of radial magnetic flux density near the thruster exit. Such magnetic profile suppressed the discharge current. However, the specific impulse decreased. As a result, the thrust efficiency of TCHT-3B was lower than that of TCHT-3A. In the input power range of 120–180W, TCHT-3 achieved higher thrust efficiency than TCHT-2 did. TCHT-series showed that Hall thrusters with circular cross-sectional discharge chambers were suitable for low power Hall thrusters.
