In PIXE, a focused beam of protons or alpha particles irradiates the sample, producing characteristic X-rays detected by a Si(Li) detector. Each element emits a unique X-ray spectrum, allowing precise elemental identification n multi-component sample matrices.
Particle-Induced X-ray Emission (PIXE) is an X-ray spectrometric method for non-destructive, multi-elemental analysis of solids, liquids, biological samples, and thin-film materials (e.g., aerosol filters). An accelerated particle beam—most commonly protons or α particles—irradiates the sample, and the induced X-ray emission is measured with a Si(Li) detector. The elemental composition is derived from the recorded X-ray spectrum. Because the penetration depth of ionizing particles depends on their energy (typically 1–5 MeV), PIXE enables depth profiling of elemental concentrations from sodium to uranium. When the beam is focused to micrometer dimensions, PIXE can also be used for microstructural analysis, providing both elemental concentrations and their spatial distributions.
PIXE is widely used for analyzing environmental samples, aerosol filters, biological materials, and cultural heritage objects.
Advantages:
- Non-destructive
- Minimal sample preparation
- Rapid analysis
- Simultaneous detection of elements heavier than Mg
- High sensitivity to trace elements (Z ≥ 11) down to 10⁻⁶–10⁻⁷ by mass, low background
- Depth profiling up to ~40 µm
- 2D/3D elemental mapping capability
Limitations:
- Limited to near-surface analysis due to finite particle range
- Cannot detect very light elements (Z ≤ 11 in current setup)
- May require complementary techniques (e.g., PIGE) for light elements detection
Applications:
- Investigantions of cobalt-chrome-molybdenum super alloy steel: DOI: 10.1007/s00170-020-06236-3
- the compositional analysis of aerosol filters for air pollution studies: DOI: 10.1016/j.buildenv.2022.109429