A first method is to simply direct the e beam towards {HEAD ~ the wafer surface} at one point for {TAIL ~ a certain time} until X rays are caused to be emitted from the sample in response to the e beam 
for
A first method is to simply direct the e beam towards { HEAD ~ the wafer surface } at one point for { TAIL ~ a certain time } until X rays are caused to be emitted from the sample in response to the e beam
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH