The event diffraction coordinates are shown with the bow-tie region
drawn around them. The inner
outlines the source region and
outline the background regions.
This shows the PI vs wavelength regions for LETG/HRC-S, for three
different source-photon-loss fractions. (NOTE: the plotted event
coordinates are for a simulation and are not intendended to be an
accurate mapping of the actual HRC-S PI distribution.)