An X-Ray Micro-Beam Technique: I - Collimation

Abstract

An X-ray micro-beam technique is described which depends on the use of X-ray beams down to approximately 1 μ diameter, obtained by means of lead glass capillaries The micro-beam precision camera incorporates collimator holders for aligning the capillaries, and enables simultaneous transmission and back-reflection photographs to be taken The effect of the divergence of the X-ray beam on the photographs is considered, and a formula is derived for the mean value of the divergence at the specimen. The optimum collimating conditions are discussed in relation to maximum resolution and minimum exposure The use of totally reflecting glass collimators is considered. An example is given of the application of the micro-beam technique to the study of cold-worked metals. It is found that, using a high intensity generator, single reflections can be obtained from crystals of diameter of the order of 2 μ in about 10 hours.