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Methoden und Instrumentierung Poster: Mi., 14:00–16:30 M-P70
Investigations on spatial grain patterns for identification of manufactured,
polycrystalline products by imaging diffraction
André Rothkirch 1
1 Hasylab/Desy, Notkestr. 85, 22607 Hamburg
Manufactured goods are supposed to look the same and be of reproducible quality and
same attributes, thus they are very similar and are hard to classify/identify. Grain
spatial distributions in materials are assumed to be non-reproducible (i.e. given by
chance) implying a variation between goods of a same production charge with respect
to their grain pattern and orientation and thus offering a possible feature for individual
sample identification. Such identification would, within given limits, allow the individual
handling of goods, i.e. to use the “built in fingerprint” for certification purposes
(e.g. to use it as a seal to proof origin of highly valuable spare parts, to track/prevent
the non-intended use or shipping of goods in terms of export control etc.). A “proof of
concept” has been made for the discrimination of goods by 2D grain patterns. 20 EUR-
Cent coins have been chosen as test sample(s) and diffraction images have been taken.
Several measurements of a single sample were done to define a basis for pattern comparison
and to determine limits for sample adjustment accuracy. Measurements by
interchanging coins, including remounting the sample holder, have been made to account
for sample mounting accuracy and to perform a comparison of different coins.
Methods being used will be presented and comparison results of different coins will be
given.