“…In Rayleigh scattering, photons are scattered by bound electrons in a process in which the atom is neither ionized nor excited. The photon loses only a negligible fraction of its energy, since the recoil is by the entire atom including the nucleus, rather than by an individual atomic electron as in the Compton effect (Hubbell, 1999(Hubbell, , 2006. For the low energy region below 100 keV, the Rayleigh scattering is significantly the sole component of the elastic scattering (Kissel, 2000;Kissel et al, 1980).…”