The Polarization of General X-Radiation from Thick Targets

Abstract

The method applied in this experiment is that of 90\ifmmode^\circ\else\textdegree\fi{} scattering combined with the balanced filter method. Bands of the x-ray spectrum between the $K$-absorption limits of molybdenum and columbium, of palladium and rhodium and of tungsten and tantalum, from targets of tungsten, copper and aluminum have been tested for polarization, using potentials from about 20 kilovolts to 100 kilovolts. Besides the confirmation of the previous experimental ${\mathrm{results}}^{1}$ about the relation between polarization and voltage and the relation between polarization and wave-length, two other points have been demonstrated more quantitatively. First, while the maximum experimental value of polarization was not over 60 percent, the polarization at the quantum voltage of the band by extrapolation is nearly complete for all targets and all wave-length bands. Second, the polarization of x-rays of a given wave-length from targets of lower atomic number is higher than that from targets of higher atomic number, except near the quantum voltage where they approach 100 percent.