Only 1 or 2 Tesla field from a station at an L1 stationary orbit point, according to https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmosphere.html htt

Only 1 or 2 Tesla field from a station at an L1 stationary orbit point, according to https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmosphere.html https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmo... Of course, actually getting that much material there, powering it, maintaining it, keeping it at the L1 point, whether it ends up being effective are all open questions.