Necessity of Quadrupolar Trap

Maxwell (~1880) showed that a perfect conductor adjacent to a dipole formed an image dipole
Chapman (~1930) realized that a neutral plasma was like a perfect conductor
Two dipoles have some quadrupole moment
Therefore, every dipole embedded in a plasma, MUST form a quadrupolar region, which is also a trap. (Nobel prize for Paul trap)
This trap is embedded in the high latitude cusp

Maxwell (~1880) showed that a perfect conductor adjacent to a dipole formed an image dipole