At the Advanced Light Source in Berkeley we have instrumented a beam line t
hat is devoted exclusively to X-ray micro-diffraction problems. By micro-di
ffraction we mean those classes of problems in Physics and Materials Scienc
e that require X-ray beam sizes in the sub-micron range. The instrument is
for instance, capable of probing a sub-micron size volume inside micron-siz
ed aluminum metal grains buried under a silicon dioxide insulating layer. T
he resulting Laue pattern is collected on a large area CCD detector and aut
omatically indexed to yield the grain orientation and deviatoric (distortio
nal) strain tensor of this sub-micron volume. A four-crystal monochromator
is then inserted into the beam. which allows monochromatic light to illumin
ate the same part of the sample. Measurement of the diffracted photon energ
y allows for the determination of d spacings. The combination of white and
monochromatic beam measurements allow for the determination of the total st
rain/stress tensor (6 components) inside each sub-micron-sized illuminated
volume of the sample. (C) 2001 Elsevier Science B.V. All rights reserved.