H. Elghandoor et al., DETECTION OF RADIATION DEFORMATION IN CRYSTALLINE POLYMERS USING THE SPECKLE PHOTOGRAPHY TECHNIQUE, Optics and Laser Technology, 27(1), 1995, pp. 65-67
In order to measure the resulting deformation due to gamma irradiation
of polymers, a new optical technique, namely speckle-photography, was
established and used. Thin films of tetrafluoroethene, with constant
thickness were irradiated by different doses of gamma rays and the dif
fraction patterns of a laser beam passing through these films were rec
orded using the speckle photography technique. This technique has been
applied to detect the radiation deformation in (Teflon) TFE, which is
a crystalline polymer. A diffraction pattern due to the TFE thin laye
r is obtained and superimposed on the interference pattern displaying
the speckle pattern pairs recorded on the same emulsion. The intensity
of the obtained diffraction pattern was found to decrease by increasi
ng the radiation dose from 5 to 12 Mrad from a Cobalt-60 source, and i
t vanishes at 12 Mrad dose. This may be attributed to the decrease in
the degree of crystallinity of the TFE polymer with increasing radiati
on dose.