Valuable cultural properties are inheritances not only in Japan
but also in the world and should be preserved in good condition
for a long time. If it is possible to inspect cultural properties
to learn how they were and what they were made of, it would provide
most beneficial information for determining their ages, studying
their historical background, and also deciding methods of preservation
and repairs.
X-ray or gamma-ray radiography is usually applied to inspect cultural
properties non-destructively. This method is useful to visualize
metals such as bronze, copper, iron inside an object. But, it
is difficult to visualize organic matter such as paper, cloth,
and wood inside an object by this method. Because X-rays or gamma-rays
are heavily attenuated by metals but are easily transmitted by
paper and wood. A new non-destructive inspection method in which
neutron radiography and gamma-radiography are combined has been
developed. With a neutron radiography and gamma-radiography device
installed at the research reactor, each image was synthesized
as a color image and finally a clear projection image was successfully
obtained. The use of a highly sensitive neutron imaging plate,
which was developed by JAERI, made a significant reduction to
the exposure time and also to the radioactivity of the sample. |
