I would like to invite you to peer review my idea.
Has anyone heard of the Dual Stage 4 Grid Ion Drive? Please check out the numbers:
https://en.wikipedia.org/wiki/Dual-Stage_4-Grid
https://www.esa.int/gsp/ACT/doc/PRO/ACT-RPR-PRO-IAC2006-DS4G-C4.4.7.pdf
Based on these numbers...