Compton Scattering Experiments with Polychromatic Radiation

We show an iterative algorithm that allows to obtain accurate Compton profiles J(q) from Compton scattering spectra I2 (ω2), if the excitation radiation is not strictly monochromatic. It requires knowledge of the spectral distribution of the primary radiation I1(ω1), validity of the impulse approximation and dominance of a monochromatic part in I1(ω1) over the polychromatic rest. Conversely, the primary spectrum is often experimentally not directly accessible. In such a situation it is possible to evaluate the primary spectrum I1(ω1) from the spectrum of scattered photons, I2(ω2), with a similar iterative algorithm. We use a scattering target of high atomic number in order to ensure that the elastically scattered photons dominate the inelastically scattered ones. From the scattered spectrum we get a model for the Compton profile that allows us to separate the inelastic part of the scattered spectrum from the elastic part, which, in turn, is proportional to the spectral distribution of the primary radiation.