A THREE-WAVE METHOD FOR MEASURING THE WAVE – TRAIN LENGTH OF X-RAY RADIATION

Abstract

In classical works on the theory of the X-ray interference, at calculating the intensity of the X-ray waves in case of scattering in gases, liquids and amorphous solid bodies, as well as crystals, it is supposed that the whole amount to be radiated, regardless of its dimensions, coherently scatters the X-ray waves. However, the review of scientific literature on the theory of the X-ray interference shows that to define the width and intensity of diffraction maximums accurately, it is necessary to take into consideration the duration of coherent radiation. In the case, when the crystal thickness is equal to or less than the length of the wave-train, the duration of the coherent radiation need not be taken into account, while when the crystal thickness is more than the length of the wave-train, the neglect of the coherent radiation duration brings about inadmissible errors. The dependence of intensity of the scattered waves on the coherent radiation duration has been investigated only theoretically. Therefore, in the theory of interference, as in general in X-ray studies, the determination of the wave-train length of the X-ray radiation is important. This is especially essential for X-ray interference and holography, as well as for testing the theoretical concepts.

Based on what is mentioned above, a method for measuring the wave – train length of X-ray radiation by a three-wave interferometer distinguished by high accuracy is proposed. It is shown that at the given plane configuration of the described device, the wave- train length of a certain length of the wave and its harmonics can be measured. The three-waved interferometer can be especially useful when using synchrotron radiation.