Study of degradation behavior in Kapton foil after gamma irradiation at low fluence

Abstract

Degradation in Kapton foil after gamma irradiation at low fluence is presented. These foils are irradiated for doses ranging from 10 to 500 kGy. The irradiated (10–50 kGy) Kapton foils show an uniform increase in visible absorption from 500 to 800 nm that decreases for further irradiation up to 500 kGy. FTIR spectra show first decrease in the absorption for all the peaks from 10 to 50 kGy and then increase from 50 to 500 kGy irradiation. Absorption of water moisture has also been observed at low fluence (∼10 kGy) that decreases at higher doses of irradiation. Difference spectra of Kapton before and after irradiation show chain scission at low fluence. This chain scission creates various types of defects, radicals and color centers. The reorganization/cross-linking of bonds is found at higher doses (>50 kGy) of irradiation, where the moisture absorbed at low doses of irradiation plays an important role. The Kapton foil shows opposite nature in terms of chain scission and cross-linking in comparison to the Poly (methyl methacrylate) irradiated in similar conditions.

KEYWORDS:

• Gamma irradiation
• Kapton
• Chain scission
• Cross-linking
• Defects

Acknowledgements

The authors are thankful to S. N. Jha for providing Kapton foils for this experiment. The help provided by S. Kher for gamma irradiation of Kapton foil is gratefully acknowledged.

Disclosure statement

No potential conflict of interest was reported by the author(s).