Study the modifications induced by alpha particles in cellulose nitrate NTD

Abstract

Cellulose Nitrate (CN-85) polymer samples were irradiated by alpha particles with different fluences varying from 1.45 × 106 to 7.2 × 106 particles/cm2 using a 241Am source. The optical and structural alterations produced in CN-85 nuclear track detector (NTD) by alpha particles were studied using Ultraviolet-visible, photoluminescence spectroscopy and X-ray diffraction techniques. The results of UV–VIS analysis demonstrate that the transmittance diminishes as the fluences of alpha particle increase. The effect of alpha irradiation on direct and indirect optical band energy gap (Eg) was observed, and the Urbach's energy (Eu) calculations reveal a reverse linear relation between Eu and Eg. The integrated intensity (I) under the PL spectra exhibits a linear relation with the alpha-particle fluences through the specified range of fluences. This linear relation gives the possibility to use the CN-85 detector for alpha particle detection using photoluminescence spectroscopy. X-ray diffraction of the irradiated CN-85 samples show a broadening in the FWHM of diffracted peak and this is due to the decrease in the crystallite size that indicates the dominant of disorder atomic structure in alpha irradiated samples. The obtained results show an improvement in the studied properties of the CN-85 polymer after irradiated with the alpha particles.