الفهرس 
1.1 Radiation typesOnly 14 pages are availabe for public view
 |  | from | 114 |  |  |
| | | from | 114 | | |
Abstract
Exposure of Makrofol DE 1-1 nuclear track detectors to high gamma ray doses causes a great
effect on their structural and etching properties, as well as on the recorded track parameters.
Samples of Makrofol DE 1-1 SSNTDs were irradiated with gamma doses in the range of
1-100 kGy using 1.25 MeV 60Co source of dose rate 4 kGy/h. Etching and optical
characterization of these detectors have been respectively studied through the measurements of
bulk-etch rate, VB, and UV-visible absorption spectra of blank and γ- irradiated samples.
Results reveal that VB shows an increase with increasing γ-dose, while the etching activation
energy, EB, shows a decrease. The UV-visible spectra of γ- irradiated samples revealed color
centers in the range (310-320 nm). The optical band gap energies (direct and indirect) were
found to decrease with increasing γ- dose. Values of direct band gap energies (4.33-4.12 eV)
have been found to be higher than those extracted from indirect approach (4.12-3.82 eV) at the
same gamma-dose. Results of the present work have been explained on the basis of
γ-interaction mechanisms with the polymeric detectors, and the formation of bond breakage,
chain scission, free radicals etc. The use of Makrofol DE 1-1 in gamma dose determination is
also discussed.