Development of a radiation tolerant laser-induced breakdown spectroscopy system using a single crystal micro-chip laser for remote elemental analysis

ABSTRACT

For the development of the remote elemental analysis method in a radiation environment based on the laser-induced breakdown spectroscopy (LIBS), the radiation effects on the laser oscillation properties of the single crystal (SC) Nd:YAG microchip laser (MCL) were investigated and compared with those of ceramic Nd:YAG MCL. The laser oscillation properties were measured under gamma ray irradiation as a function of dose rate. The effects on the SC MCL properties were very small compared to those on the ceramics, indicating minimal radiation effects on the LIBS signal when using SC MCL. Pulse energy and oscillating build-up time (BUT) were measured for cumulative dose exceeding 1400 kGy. The pulse energy remained stable under irradiation. The BUT also remained stable, demonstrating negligible optical loss accumulation that could affect laser properties even at the demonstrated cumulative dose. The results indicate that the effects of dose rate and cumulative dose on SC MCL laser properties are minimal. The SC MCL was then integrated into the LIBS system, and the gadolinium signal was successfully measured at a dose rate of 5 kGy/hr. These findings highlight the radiation tolerance of SC MCL for remote LIBS applications in harsh radiation environments.

KEYWORDS:

• Radiation tolerance
• gamma ray
• laser-induced breakdown spectroscopy
• Nd:yag
• microchip
• single crystal
• gadolinium
• simulated fuel debris

Acknowledgments

The authors wish to thank Dr M. Saeki and Dr T. Taguchi of QST for their support.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study includes a part of the results of “Project of Decommissioning and Contaminated Water Management (Development of Analysis and Estimation Technology for Characterization of Fuel Debris; Development of Technologies for Enhanced Analysis Accuracy, Thermal Behavior Estimation, and Abbreviated Analysis),” the Japanese Ministry of Economy, Trade and Industry as The Subsidy Program, Japan.