this requires Isp in the high 10-100k, likely sub-1M range (think particle accelerators) instead of sub-1k (think very high temperature nuclear gas heaters).
Some of the better ones that are actually in use get in the range of low thousands, like ~3k or so, but keep in mind that the thrust is so low that even just getting to the Moon takes months. They're only suitable for unmanned craft, and even then, only after you get into orbit and if you don't care about taking potentially many years to get somewhere outside the local SoI.
