PENGARUH ENERGI FOTON SINAR-X TERHADAP EFISIENSI ABSORBSI DARI F-CENTER PADA KRISTAL LiF

Abstract

There are two purposes in this research the first is to find out the effect of the x-ray photon energy on the absorption efficiency of F-center of LiF crystal. The second is to find out in what energy level the x-ray photon occurred associated to the  absorption efficiency of F-centers is maximum. Sample is a single crystal  from Physics Laboratory in Padang State University, with the crystal thickness is 0.302 cm. The F-centers were created by using the Cr, Cu and Mo x-ray target whith photon energy are 5.42keV, 8.03 keV and 17.4 keV respectively. The data were collected in BATAN Bandung for the Cr and Cu x-ray target, where as at Department of Material Engginering on Bandung Institute of Technology (ITB) for the Mo x-ray target. The absorptions spectrum of F-centers are obtained by using UV/VIS Spectrometer at Department of Chemistry on ITB. It is found that F-centers for three targets occured at the same wavelength 190 nm but on the other hand showed  different in the maximum absorption i.e: 91.18 %, 99.12 % and 98.89 % repectevely for Cr, Cu and Mo x-ray target. Further, we found from the plot of the maximum absorption efficiency as a function of x-ray photon energy that the maximum absorptions efficiency decrease by increasing the foton energy. This research is supported by evidence that amount the electrons and hole pairs per volume is also decrease by the x-ray photon energy i.e : 1.0827 × 10¹⁸ number/cm³, 1.02 × 10¹⁸ number/cm³ dan 0.921 × 10¹⁸ number/cm³ for Cr, Cu and Mo x-ray target respectively.

Keywords: energy level of the x-ray photon, absorption efficiency, F-centers, LiF