Daniela Adriana LĂCĂTUŞ1 Supervisor: Alexander Pavlovich KOBZEV ION BEAM ANALYSIS Mădălina BADEA1 Daniela Adriana LĂCĂTUŞ1 Alin Răzvan PARASCHIV1 Katarzyna ZIELIŃSKA2 Supervisor: Alexander Pavlovich KOBZEV 1 Research Center for Atomic Physics and Astrophysics, Faculty of Physics, University of Bucharest, Bucharest, Romania 2 Nicolaus Copernicus University, Poland
Overview Ion Beam Analysis (IBA) is based on the interaction, at both the atomic and the nuclear level, between accelerated charged particles and the bombarded material. When a charged particle moving at high speed strikes a material, it interacts with the electrons and nuclei of the material atoms, slows down and possibly deviates from its initial trajectory. This can lead to the emission of particles or radiation whose energy is characteristic of the elements which constitute the sample material.
Van de Graaff Accelerator
Van de Graaff Accelerator Parameters of the EG-5 Accelerator: Energy region: 0.9 – 3.5 MeV Beam intensity: 30 μA for H, 10 μA for He Energy spread: <500 eV Precision of energy: 2 keV Number of beam lines: 6
Ion beam techniques TECHNIQUE ION BEAM SIGNAL DETECTED RBS (Rutherford Backscattering Spectrometry) 4He+, H+ elastically scattered ions ERD (Elastic Recoil Detection) 4He+ recoiled target nuclei PIXE (Particle-induced X-ray Emission) H+ X-rays NRA (Nuclear Reaction Analysis) H+, 4He+ prompt product particles or gamma-rays
RBS (Rutherford Backscattering Spectrometry) RBS demonstrates the electrostatic repulsion between high energy incident ions and target nuclei. The specimen is bombarded with a monoenergetic beam of 4He+ particles and the backscattered particles are detected. θ
Equations RBS The kinematic factor: The differential cross-section of the solid angle unit: Energy loss: Channel energy thickness:
RBS (Rutherford Backscattering Spectrometry)
RBS (Rutherford Backscattering Spectrometry)
Element concentrations (at.%) RBS (Rutherford Backscattering Spectrometry) Thickness Element concentrations (at.%) [nm] Cu O C Fe Si 26.30 55.00 20.00 25.00 0.00 32.9 90.00 18.6 10.00 37.1 40.4 5.00 85.00 18083.2 100.00
NRA (Nuclear Reaction Analysis) NRA (Nuclear Reaction Analysis) is based on nuclear reactions and the analysis is performed with charged particles. NRA has demonstrated its usefulness in the study of the oxidation and deposition of hydrocarbon residue on metallic surfaces.
ERD (Elastic Recoil Detection) ERD is a technique for a quantitative analysis of light elements in solids. Heavy ions collide with a sample and atoms (H, He) are ejected from the sample. The incident energetic ions typically have MeV of energy, enough to kick out the atoms being struck. For ERD, the mass of the incident particle must be greater than that of the target nucleus.
Setup
ERD (Elastic Recoil Detection)
PIXE (Particle-induced X-ray Emission) Particle-induced X-ray emission or proton-induced X-ray emission (PIXE) is a technique used in the determining of the elemental make-up of a material or sample. When a material is exposed to an ion beam, atomic interactions occur that give off EM radiation of wavelengths in the x-ray part of the electromagnetic spectrum specific to an element. PIXE is a powerful yet non-destructive elemental analysis technique now used routinely in different fields of research.
PIXE (Particle-induced X-ray Emission)
PIXE (Particle-induced X-ray Emission)
PIXE (Particle-induced X-ray Emission) Element Concentration At. % Method C 41 RBS K 0.1 PIXE N 20.5 Ca 0.53 O 28 Mn 0.007 F 2.6 Fe 0.14 Na 2.5 Cu 0.002 Mg 1.3 Zn 0.01 Al As 0.001 Si 1.8 Sr 0.0006 S 0.2 Zr 0.005 Cl Ba
Conclusions Non-destructive methods Depths profile of elements from H to heavier using relatively low energies (1-3 MeV) Thickness from 1015-1019 at/cm2 High sensitivity of measurement (precision of 5% concentration of heavy and 10% for lighter in the case of RBS; NRA precision for lighter of 1%) PIXE exact determination of elements present in sample with extremely high accuracy Applicable in different fields of research
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