A magnetic structure is attached to move with the forcer and has a periodic configuration corresponding to the forcer and in {HEAD ~ magnetic interchange relation} to {TAIL ~ the platen} 
to
A magnetic structure is attached to move with the forcer and has a periodic configuration corresponding to the forcer and in { HEAD ~ magnetic interchange relation } to { TAIL ~ the platen }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL