Muon-Based Elemental Analysis Techniques

Muons, heavy relatives of electrons, offer a powerful route to non-destructive elemental analysis by harnessing their unique interaction with matter. When a negative muon is implanted into a sample, it slows and is captured by atomic nuclei, forming a muonic atom. As the muon cascades through energy levels it emits characteristic high-energy X-rays that are element-specific and highly penetrating, enabling detection of elements from hydrogen to heavy metals well below the surface. Complementary measurements of muon lifetimes reveal local elemental concentrations through variations in capture and decay rates. By tuning the energy of the incoming muon beam, analysis can be depth-selective, providing layer-by-layer profiles without physical sampling. Integration with advanced detectors and tomographic reconstruction algorithms has further enabled three-dimensional mapping of elemental distributions in bulk samples. Applications span steel production quality control, battery material characterisation, cosmochemical studies of meteorites and conservation science for cultural heritage objects. The high sensitivity to low atomic number elements, together with deep probing capability and preservation of sample integrity, makes muon-based techniques a robust complement to conventional X-ray and neutron methods across both research and industry.

Research from Nature Portfolio

Recent studies have refined muon-lifetime analysis to achieve non-destructive, depth-selective quantification of carbon content in commercial steels, delivering sub-percent accuracy across multiple layers via careful control of muon implantation energy. A novel three-dimensional elemental imaging approach combined muonic X-ray emission with cadmium telluride double-sided strip detectors, reconstructing volumetric distributions of light elements such as carbon through tomographic algorithms. Foundational work using an intense continuous muon beam enabled the first non-destructive elemental analysis of a carbonaceous chondrite, accurately detecting elements including magnesium, silicon, iron and carbon, thus establishing muon-based methods for cosmochemical investigations.

Research from all publishers

Independent investigations have extended the scope of muon-based analysis. In energy storage research, muon-induced X-ray emission has been applied to probe buried electrode layers in commercial batteries, detecting lithium and transition metals at depths up to 700 µm. Cultural heritage studies have employed negative muons to non-destructively analyse alloy compositions and surface-enrichment layers in ancient bronzes and Roman silver coinage, revealing production techniques and provenance. Instrumental developments have characterised continuous muon sources and optimised detection configurations, achieving high signal-to-noise ratios and demonstrating the feasibility of routine depth-sensitive elemental assessments for industrial and scientific applications.

Muon-Based Elemental Analysis Techniques publication trend

The graph below shows the total number of articles in muon-based elemental analysis techniques across all publications each year (not limited to Nature Index journals).

Technical terms

Negative muon: A negatively charged elementary particle used as a non-destructive probe due to its ability to be captured by atomic nuclei.

Muonic atom: An exotic atom formed when a muon replaces an electron in an atomic orbital, releasing high-energy X-rays during de-excitation.

Muonic X-ray emission (MIXE): Element-specific, high-energy X-rays emitted as muons transition to lower energy levels within muonic atoms.

Muon lifetime analysis: A technique measuring the decay time of muons in matter to infer local elemental composition based on capture probabilities.

Depth-selective analysis: Control of muon beam energy to stop muons at predetermined depths, enabling layer-by-layer elemental profiling.

References

1. Development of a non-destructive depth-selective quantification method for sub-percent carbon contents in steel using negative muon lifetime analysis. Scientific Reports (2024).
2. Non-destructive 3D imaging method using muonic X-rays and a CdTe double-sided strip detector. Scientific Reports (2022).
3. Non-destructive elemental analysis of a carbonaceous chondrite with direct current Muon beam at MuSIC. Scientific Reports (2017).
4. Overcoming the probing-depth dilemma in spectroscopic analyses of batteries with muon-induced X-ray emission (MIXE). Journal of Materials Chemistry A (2025).
5. The non-destructive investigation of a late antique knob bow fibula (Bügelknopffibel) from Kaiseraugst/CH using Muon Induced X-ray Emission (MIXE). Heritage Science (2023).
6. Using Negative Muons as a Probe for Depth Profiling Silver Roman Coinage. Heritage (2019).
7. Characterization of a Continuous Muon Source for the Non-Destructive and Depth-Selective Elemental Composition Analysis by Muon Induced X- and Gamma-rays. Applied Sciences (2022).