Measurements of Intensity of Compton Modified Radiation by Means of Filters

A new method of measuring the ratio of the intensity of the modified to the unmodified scattering by using a triple balanced filter has been developed. With the $K_{\alpha }$ radiation of molybdenum three balanced absorption filters containing zirconium, yttrium and strontium, respectively, make it possible to absorb or transmit either the modified or unmodified $K_{\alpha }$ lines or both if the angle of scattering is sufficiently large so that the shortest wave-length of the modified line is greater than the critical absorption wave-length of yttrium. This method makes possible measurements of the modified radiation not only for the scattering by solids but also for the scattering by gases for which case the theory and experiment can be directly compared. Measurements of the ratio of intensity of the modified to the unmodified scattering have been made at $\varphi =120\mathrm{}°$ for oxygen, nitrogen and argon as well as for several solid elements and compounds. The results for gases are found to be in good accord with the wave-mechanics theory of scattering as developed independently by Wentzel and Waller.