The X-ray source is rectangular collimated beam. A laser is collimated and then reflected off of a beam-splitting mirror. A perfectly collimated light beam, with no divergence, would not disperse with distance. Second, the atmosphere may cause an otherwise tightly collimated energy beam to spread. Grisms are inserted into a camera beam that is already collimated. The orientation of the fringes varies when the beam is not perfectly collimated. X-rays are produced and the beam is collimated to create a line. Diagnostic X-ray beams can be collimated to large or small beams. The reflector options are parabolic (for collimated light) or elliptical (for focused light). The instrument serves to determine the structure of interfaces using highly collimated neutron beams. For such sources, the MPE is higher than for collimated laser beams. Other forms of electromagnetic radiation can also be collimated. Separating the plates, however, necessitates that the illuminating light be collimated. It is also collimated on the orbit plane of the electrons. Because of the much higher flux of usable collimated X-rays, shorter exposure times become possible.