This answer estimates that the DAWN spacecraft's solar-electric propulsion accelerated about 3 milligrams of Xe+1 per second, using roughly 1350 Watts of electrical power. I estimate that 3 mg/sec of Xe+1 should be about 2.2 amps, so the acceleration potential might be in the ballpark of 600 volts.
Is the choice of voltages near 1 kilovolt the result of some optimization in kinematics? If so, can it be explained quantitatively with a simple mathematical model? Would say 200 or 2000 volts have both resulted in poorer use of the available
- solar-electric power?