{TAIL ~ A magnetic field} at the surface redirects ions and {HEAD ~ electrons} based on their velocity and charge 
{ TAIL ~ A magnetic field } at the surface redirects ions and { HEAD ~ electrons } based on their velocity and charge
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH