Rapid suppression and modulation of the diffraction beam in a single crystal excited by ultrasound

The results of a theoretical analysis of the influence of a high-frequency standing acoustic wave on the angular spectrum of a diffracted beam in a perfect crystal are presented. The rapid suppression and modulation of the intensity at the center of the diffraction pattern are found for the first time. The characteristic duration of this modulation is many times smaller than the period of the acoustic wave. These effects can be used for the suppression and modulation of a highly collimated monochromatic beam of synchrotron radiation. (orig.)