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