Scientists at the University of Michigan have proposed a new type of Hall thruster that runs on krypton and generates much more thrust than existing much higher power thrusters. This was reported in a press release on Phys.org.
The operation of the Hall electric motor is based on the effect that occurs when a magnetic field is applied to moving charged particles, such as xenon gas ions. The latter deviate from their trajectory, due to which another current arises, perpendicular to the main direction. This creates additional thrust and allows you to achieve a high flow rate of the working fluid, that is, ionized gas.
Early researchers assumed that only a certain amount of current could be passed through a unit area of the motor, which directly affected the thrust force. In the new work, scientists managed to increase the amount of force generated per unit area by almost 10 times. The modified H9 engine, called MUSCLE, accelerated to 37.5 kilowatts with an overall efficiency of about 49 percent, not far from the 62 percent efficiency at a design output of nine kilowatts.
When switching from argon to krypton, the engine power increased to 45 kilowatts. With an efficiency of 51 percent, a maximum thrust of 1.8 Newtons was achieved, which corresponds to the much more powerful 100-kilowatt X3 Hall motor. However, for use in interplanetary manned missions, a good cooling system would be required.