  Multi-energy radiography is a new direction in non-destructive testing. Its
specific feature is separate detection of penetrating radiation in several
energy channels. Multi-energy radiography allows quantitative determination of
the atomic composition of objects. This is its principal advantage over
conventional radiography. In particular, dual-energy radiography allows
determination of the effective atomic number of a material with an accuracy of
up to 80-90%. Development of three-energy radiography and radiography of higher
multiplicity makes it possible to further improve the reconstruction of an
objects chemical composition. This presents the possibility, for example, of
detection of explosives and other illegal objects in luggage with a reliability
approaching 100%. These developments can find application not only in
anti-terrorist activities, but also in areas such as industrial testing and
nuclear medicine.
