A new method to detect an X-ray diffracted beam at an angle of 90°

A standard procedure cannot be used to detect a back-diffracted X-ray beam (h-beam) at a diffraction angle of 90° (back-diffraction) because the detector will intercept the incident beam. A new method is proposed in which a silicon single crystal simultaneously back-diffracts and detects the variation of the photon counting rate when the crystal is in and out of the X-ray back-diffraction condition. The detected intensity shows the inverted diffraction profile; that is, a dip in the photon counting rate due to the photons that are being back-diffracted. The experimental results presented here show such a dip, referred to here as the anti-h peak or the inverted rocking curve (IRC), for different situations.