IBA Analytical Capabilities
When an energetic ion beam hits a sample it will interact with the atoms through a number of very complex interactions.
Some of the interactions and the associated IBA techniques used at ANSTO are listed below, and are schematically shown with the animations. To find more about a specific technique click on the links in the tables below.
Particle Induced X-ray Emission (PIXE)Interaction: Induced characteristic X-rays via interactions with the electron cloud
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Rutherford Backscattering (RBS)Interaction: Incident ions back-scattered from the atom's nucleus |
Particle Induced Gamma Emission (PIGE)Interaction: Induced gamma rays from the atom's nucleus |
Elastic Recoil Detection (ERD & RToF)Interaction: Knocked and recoiled target atoms in the forward direction |
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From the measured reaction products and their intensities, quantitative data on the sample's constituent elements and their spatial distributions can be readily obtained. Depending on the technique used and the sample under investigation, probing depths are in the range 5 nm to 100 mm, and elemental sensitivities are typically of the order 1 to 100 ppm by weight.
The outline of the experimental set-up used at ANSTO's IBA laboratory is shown in the figure below. Depicted on this figure are the positions of the PIXE, RBS, PIGE and PESA detectors, which are complementary and often used simultaneously to extend the range of analysed elements
| Analytical Technique | Typical Applications | Elements Detected | Sensitivity | Depth Resolution | Depth Resolution |
|---|---|---|---|---|---|
| Surface and thin film composition and thickness | Li - U | Best for heavy elements on light element substrate (eg Cu on Si) typical 10% (Li) - 0.001% (U) | 5 - 20 nm | up to 1mm | |
| Trace element composition of particulates and bulk materials | Si - U | Opimum near Fe (1ppm) elemental sensitivities range from 1 - 100ppm | typical proton range 20-50 microns | up to 1mm | |
| Trace element composition of particulates and bulk materials | Li - Al | element dependent, typical < 1 ppm for F < 40 ppm for Na < 40 ppm for Al | - | up to 1mm | |
| Isotopic tracing and profiling in materials, surfaces and interfaces | H - Si | element dependent, typically in range 1 - 100 ppm | 5 - 20 nm | up to 1mm | |
| Hydrogen in polymers, polymer interdiffusion, hydrogen in solar cells | H, D | > 0.1% | 10 - 20 nm | up to 1mm | |
| Elemental composition and structure of near surface regions. thin films | H - U | > 0.1 % | 10 - 20 nm | up to 1mm | |
| Trace element mapping in biological, environmental and geological samples | Si - U | > 100 ppm | - | up to 3μm | |
| Elemental mapping and depth profiling in materials science | H - U | > 0.1 % | > 50 nm | up to 20μm | |
| Charge collection mapping in electronic devices and detectors | - | - | - | up to 1μm |
IBA techniques are applied in various areas of scientific research. Several key IBA applications at ANSTO are in: materials analysis, environmental pollution, archaeology.