High-precision orientation of crystals using the Laue method with characteristic X-rays

A method previously developed for high-precision orientation of low-index planes of perfect or nearly perfect crystals has been extended to planes with arbitrary indices. The extension has been accomplished by predicting the back-reflexion patterns of Laue spots due to characteristic X-rays and by identifying spots which should have equal intensity when the correct orientation is obtained. It is possible to orient the specimen crystal within 0.01° of the desired orientation in favourable cases. In cases where the equal-intensity criterion cannot be used the accuracy of the orientation using the predicted pattern is at least as good as that using the conventional Laue method. Furthermore there is no need to measure angular distances between the spots or the distance between the crystal and the film.