The X rays are emitted in {TAIL ~ response} to an impinging beam, such as {HEAD ~ an electron beam}, directed towards the sample surface where a defect resides 
The X rays are emitted in { TAIL ~ response } to an impinging beam , such as { HEAD ~ an electron beam } , directed towards the sample surface where a defect resides
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH