Transient Grating Spectroscopy for accelerator applications at the European Spallation Source

Abstract The European Spallation Source (ESS) is a multi-nation, interdisciplinary research facility based on the world’s most powerful neutron source that will operate with high standards of availability and reliability minimizing downtime periods. In addition, ESS proton linac and target operation introduces significant challenges, including exposure to high radiation levels, extreme temperatures, and oxidative environments, which could lead to material property degradation. To meet these goals, critical component’s performance and aging need to be constantly monitored and assessed. Transient Grating Spectroscopy (TGS)—a laser-based technique originally developed for studying nuclear materials—has been deployed at the ESS Mechanical Measurements Lab (MML), where a dedicated test bench has been developed to assess material property degradation in particle accelerator components as part of ESS Structural Health Monitoring (SHM) program. The implementation of this method offers a powerful instrument for assessing the characteristics of the materials during the design and operation phases of ESS, enabling the study of degradation mechanisms and lifetime predictions of critical components.