Simulation of Rutherford Backscattering Cross Section of Atoms

Rutherford backscattering spectrometry is considered as a very powerful tool in surface analysis among other various techniques employed. In this work a computer program had been built for detailed study of the important parameters that influence Rutherford backscattering spectrometry including the kinematic factor or (k factor), mass resolution, Rutherford backscattering cross section, Andersen and L.Ecuyer correction factores. The simulation had been carried out for different mass target atoms, scattering angles and ion energies. Most of the data obtained are not avaliable in the literature for comparison. Introduction: Rutherford backscattering spectrometry (RBS) is an established analytical technique and latterly has been become the most commonly used in the field of ion beam technique in material science [1,2,3,4,5]. Simulation of Rutherford Backscattering Cross Section of Atoms. 88 Its power lies in speed of analysis, a completely quantitative, non destructive technique. In addition to measure the composition and thickness of thin films, mass and depth of target sample and good resolution for low mass element [3,4]. RBS is very complementary or related techniques used for surface analysis, such as Auger electron spectroscopy (AES), X-ray fluorescence spectroscopy (XRF), X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS). [6, 7] RBS is based on the electrical interaction between (ion-target) combination. RBS uses a high energy ion to examine the properties of the solid through ion backscattering technique. There are two main types of ion sources. Plasma and ion beam. The advantages of ion beam analytical method as there ease to use, non destructive and quantitative interpretation the experimental results. The application of RBS covers a wide range of branches of science such as geology, mineralogy, biology and medicine [3]. Overview of RBS yield data has been taking by researchers for various ion – target pair [8, 9 and 10]. In this paper, a computer program had been built to simulate the important parameters in RBS, such as k factor, Rutherford backscattering cross section of atoms and L.Ecuyer and Andersen cross section correction factors. Theory: RBS technique involves bombarded a surface with a monochromatic beam of high energy of ions. Some of the ions are scattered from the target through an angle (θ). The scattering angle may vary from (0 to 180 ° ). In the inelastic recoil process, the ions may give recoil energy to the target atoms and then collected in a solid state detector. The detected ions are recorded as a function of an angle or energy. In general, H and He ions are used of energies in the range of 100 keV to some MeV. 1Kinematic of the elastic scattering (k factor): The k factor is defined as the energy of scattered ion (E) divided by the initial of ion energy (Eo) and is given by [6]