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Ion Beam AnalysisIon Beam Analysis
Dolly LangaDolly LangaPhysics Department, University of Pretoria, South AfricaPhysics Department, University of Pretoria, South Africa
Blane LombergBlane LombergPhysics Department, University of the Western Cape, South AfricaPhysics Department, University of the Western Cape, South Africa
Project Supervisor: Prof Project Supervisor: Prof A.P. KobzevFrank 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 Parameters at JINR
• Produces the beams of helium ions and protons with energy in regions 0.9-3.5 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..
2
12
12
12
122
0
12
cos)sin(
MM
MMM
E
Em
BR727.DATSimulated
Channel88084080076072068064060056052048044040036032028024020016012080
Coun
ts
4,000
3,600
3,200
2,800
2,400
2,000
1,600
1,200
800
400
0
200 400 600 800 1000 1200 1400 1600
Energy [keV]
RESULTS AND DISCUSSIONRBS spectrum for the sample with the Fe and Ti layers on Si
substrate, with Ti layer containing Oxygen.
EHe = 2.035 MeV
= 100
= 1700
Si Substrate
Oxygen
Fe
Ti
Calibration:
Calibration offset = 35.72 keV
Energy per channel = 1.8782 keV/ch
Thickness:
Fe = 76 nm
Ti = 62 nm
Concentrations in Ti layer:
Ti = 30 at %
O = 70 at %
M259.DATSimulated
Channel800760720680640600560520480440400360320280240200160120
Cou
nts
2,000
1,800
1,600
1,400
1,200
1,000
800
600
400
200
0
100 200 300 400 500 600 700 800
Energy [keV]
RBS spectrum for the sample with the Ge and Si multi-layers on Si substrate
Si
Ge
Si substrate
EHe = 1 MeV
= 300
= 200
= 1700
PRINCIPLE OF ION BEAM ANALYSIS USEDRutherford Backscattering Spectrometry (RBS) and Elastic Recoil
Detection (ERD) setup
BR784.nraSimulated
Channel850800750700650600550500450400350300250200150
Coun
ts
6,500
6,000
5,500
5,000
4,500
4,000
3,500
3,000
2,500
2,000
1,500
1,000
500
0
300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600
Energy [keV]
BE235.nraSimulated
Channel1,000950900850800750700650600550500450400350300250200150100500
Coun
ts
700
650
600
550
500
450
400
350
300
250
200
150
100
50
0
0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300
Energy [keV]
C
O
Si
RBS and ERD spectra
EHe = 2.297 MeV
= 750
= 300
= 1350
EHe = 2.297 MeV
= 750
= 750
= 300
Thickness: (C) = 170 nm Thickness (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
Element Concen. At. % Method Element Concen. At. % Method
C 41
RBS K 0.1 PIXE
N 20.5 RBS Ca 0.53 RBS
O 28 RBS Mn 0.007 PIXE
F 2.6 RBS Fe 0.14 RBS
Na 2.5 RBS Cu 0.002
PIXE
Mg 1.3 RBS Zn 0.01 PIXE
Al 1.3 RBS As 0.001 PIXE
Si 1.8 PIXE Sr 0.0006 PIXE
S 0.2 RBS Zr 0.005 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 1014 atoms/cm2
THANK YOU
