{HEAD ~ This modified accelerator} has a narrow sharp space distribution of {TAIL ~ emitted x ray radiation} even for a low energy x ray beam 
{ HEAD ~ This modified accelerator } has a narrow sharp space distribution of { TAIL ~ emitted x ray radiation } even for a low energy x ray beam
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH