Total Reflection of X-Rays and the Index of Refraction of Certain Metals

Abstract

Total reflection of a beam of x-rays ($\lambda =0.7078\mathrm{}\mathrm{A}$) is obtained from mirrors of glass, tin, silver, selenium, and zinc. The deviations of the reflected rays at the critical positions were measured on photographic films placed 312.5 cm from the mirrors. The index of refraction was calculated from the measured critical angle in each case, with the following results: crown glass $\delta \times {10}^6=1.711\mathrm{}$; tin 3.97; silver 5.78; selenium (vitreous) 2.67; and zinc 4.59. The experimental values of $\delta$ agree with those calculated by the Drude Lorentz dispersion formula to about 0.5%. It is shown in the case of the metals that there are undoubtedly in each atom 2 electrons which have the critical $K$ absorption frequency.