Ion Beam Analysis Dolly Langa Physics Department, University of Pretoria, South Africa Blane Lomberg Physics Department, University of the Western Cape, South Africa Project Supervisor: Prof Project Supervisor: Prof A.P. Kobzev Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia

AIM OF PROJECT Analysis of contents and depth distribution of different elements in the near surface layers of solids using Rutherford Backscattering Spectrometry (RBS) Elastic Recoil Detection (ERD) Particle Induced X-ray Emission (PIXE)

OUTLINE 1.AIM OF PROJECT 2.VAN DER GRAAFF ACCELERATOR 3.PRINCIPLE OF ION BEAM ANALYSIS USED 4.RESULTS AND DISCUSSION 5.CONCLUSION

VAN DE GRAAFF ACCELERATOR

Van de Graaff Accelerator Parameters at JINR Produces the beams of helium ions and protons with energy in regions MeV Helium intensity less than 10  A and proton intensity up to 30  A. Energy spread less than 500 eV The accelerator belt moves at 20 m/s The accelerator is placed in a tank under pressure of 10 atmospheres of dry nitrogen. The accelerator EG-5 has six beam lines.

Rutherford Backscattering Spectrometry (RBS) PRINCIPLE OF ION BEAM ANALYSIS USED Conti..

RESULTS AND DISCUSSION RBS spectrum for the sample with the Fe and Ti layers on Si substrate, with Ti layer containing Oxygen. E He = MeV  = 10 0  = Si Substrate Oxygen Fe Ti Calibration: Calibration offset = keV Energy per channel = keV/ch Thickness: Fe = 76 nm Ti = 62 nm Concentrations in Ti layer: Ti = 30 at % O = 70 at %

RBS spectrum for the sample with the Ge and Si multi-layers on Si substrate Si Ge Si substrate E He = 1 MeV  = 30 0  = 20 0  = 170 0

PRINCIPLE OF ION BEAM ANALYSIS USED Rutherford Backscattering Spectrometry (RBS) and Elastic Recoil Detection (ERD) setup

C O Si RBS and ERD spectra E He = MeV  = 75 0  = 30 0  = E He = MeV  = 75 0  = 75 0  = 30 0 Thickness: (C) = 170 nmThickness (O) = 20 nm Si = 26 at %Si = 70 at % H = 40 at %H = 20 at % C = 34 at %O = 10 at % Thickness (H) = 190 nm

PRINCIPLE OF ION BEAM ANALYSIS USED Conti.. Particle Induce X-ray Emission (PIXE)

PIXE RBS

ElementConcen. At. % Method ElementConcen. At. % Method C 41 RBS K 0.1 PIXE N 20.5 RBS Ca 0.53 RBS O 28 RBS Mn PIXE F 2.6 RBS Fe 0.14 RBS Na 2.5 RBS Cu PIXE Mg 1.3 RBS Zn 0.01 PIXE Al 1.3 RBS As PIXE Si 1.8 PIXE Sr PIXE S 0.2 RBS Zr PIXE Cl 0.01 PIXE Ba 0.01 PIXE Aerosol analysis by PIXE & RBS

CONCLUSION These methods are non-destructive techniques to study materials The used methods allow the determination of depth distribution and concentration from hydrogen to heavy elements. The spectra calculations and model comparisons was executed in SIMNRA software tool, in which good agreement was achieved for RBS and ERD experiments. Furthermore, the depth resolution is done near to few nm range for these methods. The sensitivity for heavy elements is of the order atoms/cm 2

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