Plasma Thrusters Ran at 500% Beyond Old Power Limits• https://www.nextbigfuture.com, by Brian Wang
His team challenged ran a 9 kilowatt-rated Hall thruster at up to 45 kilowatts while maintaining roughly 80% of its nominal efficiency. This increased the amount of force generated per unit area by almost a factor of 10.
Hall thrusters are a well-proven technology. Previously, making larger and more powerful Hall thrusters would lose any higher power benefits from the higher mass. It turns out the old limit was not physics-based limits but engineering issues.
Now super-powered Hall Thrusters have a path to be made light and powerful enough to power high ISP megawatt propulsion.
Hall thrusters are able to accelerate their exhaust to speeds between 10 and 80 km/s (1,000–8,000 s specific impulse), with most models operating between 15 and 30 km/s. Old devices operated at 1.35 kW produce about 83 mN of thrust. High-power models have demonstrated up to 5.4 N in the laboratory. Power levels up to 100 kW have been demonstrated for xenon Hall thrusters. The new systems could achieve 40-100 newtons of power at megawatt power levels with up to 8000 ISP (80 km/second).
There will still be a need to create megawatts of light solar panels or megawatt-class space vehicle-class nuclear power sources.
As of 2009, Hall-effect thrusters ranged in input power levels from 1.35 to 10 kilowatts and had exhaust velocities of 10–50 kilometers per second, with thrust of 40–600 millinewtons and efficiency in the range of 45–60 percent.