If I wanted to generate plasma to replicate the magnetic flux density of a i.e. N42 magnet, what would be the required volume of gas/plasma to achieve this? This magnet has a pull force of 12kg at the contact surface. I have chosen to use Helium, because it has the highest ionization energy level. For references : http://plasmalab.pbworks.com/f/bfield.pdf You just need to give me a rough estimation, by using common sense.