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M: Metallphysik
M 32: Poster TU B (Symposium Tomographic Methods in Materials Research M-32.32-55)
M 32.34: Poster
Montag, 7. März 2005, 14:30–16:30, Poster TU B
Tomography with Monochromatic Neutrons — •Markus Strobl1,2, Wolfgang Treimer1,2, André Hilger1,2, and Nikolay Kardjilov1 — 1Hahn-Meitner-Institut Berlin, Glienickerstr. 100 14109 Berlin — 2Technische Fachhochschule Berlin, Luxemburger Str. 10, 13353 Berlin
A perfect Si monochromator placed in the cold neutron beam of the BER II reactor at the Hahn-Meitner-Institute provides a highly monochromatic beam. The ratio Δ λ / λ is in the range of a few percent for a wavelength λ = 0.45 nm that is fulfilling the Bragg condition for the asymmetric reflection. Although the resulting flux density is low i.e. approximately 5 × 103 cm−2s−1 this beam has advantages for special radiography and tomography applications. On one hand the effect of beam hardening can be avoided and hence a better sensitivity concerning slight density differences can be achieved. On the other hand the irradiation of samples can be reduced compared to high flux instruments in spite of the fact that the exposure time is necessarily increased. The spatial resolution of the instrument can be given with 125 µ m in horizontal respectively 200 µ m in vertical direction. Some examples of successful applications will be given.