Autori: M.Iovea, O. Duliu, et all

Editorial: Proceedings of the 9th European Conference on NDT - ECNDT Berlin September 2006 – CD-ROM, 2006.

Rezumat:

By means of a home made X-ray dual-energy computer tomography (CT)
provided with a double set of X-ray detector arrays separated by a copper foil and by
using a proper variant of filtered back projections reconstruction algorithm together
with a set of well calibrated standard samples we have been able to determine with a
precision varying between 3.5 % and 2 % the density as well as the effective atomic
number distribution in any section of a great diversity of samples.
In this way it was possible to discriminate different domestic materials that on
a normal radiography generate the same signature such as soap, paper, leather, tooth
past, the content of spray tubes, etc.
The same CT has been use to investigate different geologic samples consisting
of sediment cores collected at depth up to 600 m from the continental platform of
the Black Sea and fragments of metamorphic rocks collected from the Sibischel
shear zone from the Central Carpathian mountains. In the case of deep sea cores we
have evidenced about 225 distinct laminae, 2 to 4 mm thick that by means of time
series analysis revealed a periodicity of about 7 years, while in the case of
metamorphic rocks we have observed diverse features such as garnet size and
distribution, shear zones, mica laminations, etc. Numerical values of both density
and especially effective atomic numbers allowed distinguishing between natural
silicates and calcium carbonates, irrespective of the host rock.

Cuvinte cheie: X-Ray, dual-energy, tomography, radioscopy

URL: http://www.ndt.net/article/ecndt2006/doc/P44.pdf