a sensor for detecting a at least one of a secondary electron and reflected {HEAD ~ electron} emanated from {TAIL ~ the object}, upon exposure of the object to the electron beam 
emanated from
a sensor for detecting a at least one of a secondary electron and reflected { HEAD ~ electron } emanated from { TAIL ~ the object } , upon exposure of the object to the electron beam
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH