I was recently reading an awesome Paper that details a possible process for restarting the Martian atmosphere. The paper explains that a Sufficiently Sized artificial magnetic dipole of 1 to 2 Tesla at the L1 Lagragian Point could effectively shield Mars from Solar Wind, allowing the Atmosphere to regenerate without constant Solar-Wind ejection.
However, the manuscript never clarifies what "Sufficiently Sized" means, only detailing the strength: 1 - 2T. I assume its magnetic field has to occlude the planet.
Assuming it's a solenoid of some sort, how large would the solenoid need to be to sufficiently protect the Martian Atmosphere?
Some Related Questions:
1. How would it be possible to kick start Mars's magnetic field?
2. How strong a magnetic field would be needed to deflect cosmic rays?