Time-Space-Medium Collaboratively Modulated LIBS Combined with Matrix Dilution: From Self-Absorption to Isotope
Zhihang Lai1,2, Shujia Wu1, Cheng Xu1
1Frontiers Science Center for Rare Isotopes, State Key Laboratory of Chemistry for NBC Hazards Protection, School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000, China.
Journal of the American Chemical Society
|May 7, 2026
Summary
A new time-space-medium collaboratively modulated Laser-Induced Breakdown Spectroscopy (TSMM-LIBS) method enables rapid, in situ lithium isotope analysis. This breakthrough accurately resolves isotopic shifts for nuclear energy applications.
Area of Science:
- Nuclear Engineering and Energy Systems
- Analytical Chemistry and Spectroscopy
- Materials Science
Background:
- Global climate change necessitates deep decarbonization of energy systems, driving advancements in clean energy technologies.
- Accurate, in situ, and rapid isotopic analysis of lithium is crucial for nuclear energy systems, including fission safety and fusion fuel breeding.
- Conventional Laser-Induced Breakdown Spectroscopy (LIBS) faces limitations due to self-absorption and plasma broadening, obscuring small isotopic shifts.
Purpose of the Study:
- To develop a novel LIBS approach overcoming self-absorption and plasma broadening for high-precision lithium isotope analysis.
- To enable rapid, remote, and in situ isotopic discrimination of lithium for nuclear applications.
- To establish a robust analytical framework for lithium isotope ratio determination in various sample types.
Main Methods:
- Implementation of a time-space-medium collaboratively modulated LIBS (TSMM-LIBS) technique combined with matrix dilution.
- Development of a self-reversal indicator (SRI) and a wing-side recovery algorithm for spectral distortion correction.
- Application of an Effective Concentration Model with Self-Absorption Correction (ECM-SAC) for quantitative analysis.
Main Results:
- Simultaneous resolution of lithium doublet structure and isotopic shifts (7Li and 6Li) for the first time in LIBS.
- Significant spectral compression (fwhm to 25.65 pm) and Stark broadening reduction (to 3.87 pm), achieving sub-Doppler resolution.
- Exceptional quantitative accuracy demonstrated via cross-validation, with an optimal spectral intensity ratio yielding RMSECV of 0.041 and RPD of 6.561.
Conclusions:
- The TSMM-LIBS approach effectively suppresses self-reversal and plasma broadening, enabling unprecedented precision in lithium isotope analysis.
- The developed analytical framework provides a rapid, in situ, and accurate method for lithium isotope discrimination.
- This technology holds significant promise for nuclear material management and monitoring of tritium breeding materials in fusion reactors.
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