Abstract
Small-bubble gas injection has been routinely utilized in the operation of Spallation Neutron Source (SNS) mercury targets since 2017 to mitigate cavitation-induced erosion damage to target vessels. Strain measurements of target vessels collected in-situ during initial operation with gas injection were used to study the gas injection effect on the structural response of targets to proton pulses. A significant strain reduction owing to gas injection was found by comparing the strain measurement data during operation with and without gas injection. The research presented here focuses on quantifying strain reductions in SNS targets and evaluating the effect of small-bubble gas injection by comparing different bubbler types and target designs. The strain measurement results show the gas injection significantly reduced strain in SNS target vessels; strain values decreased by 30% to 80% for targets operating with gas injection. Stress and strain responses of SNS targets were simulated to numerically evaluate the gas injection effect. Based on the predicted stresses with and without gas injection, the fatigue lifetimes of SNS jet-flow design target were estimated using fe-safe fatigue analysis software. The simulations show these reductions should improve the fatigue life of target vessels and allow SNS targets to meet their fatigue design goal.
| Original language | English |
|---|---|
| Article number | 113797 |
| Journal | Materials and Design |
| Volume | 253 |
| DOIs | |
| State | Published - May 2025 |
Funding
The authors would like to acknowledge individuals who contributed to strain measurement, Yun Liu, Cary D. Long, Robert L. Sangrey, Charles C. Peters, David Brown, Willem Blokland and Kevin Johns. The SNS is sponsored by the Office of Science, U.S. Department of Energy, and managed by UT-Battelle, LLC for the U.S. Department of Energy under Contract DE-AC05-00OR22725 . The authors would like to acknowledge individuals who contributed to the target strain measurements, Yun Liu, Cary D. Long, Robert L. Sangrey, Charles C. Peters, David Brown, Willem Blokland and Kevin Johns. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract DE-AC05-00OR22725. This research used resources of the Spallation Neutron Source, which is a DOE Office of Science User Facility.
Keywords
- Fatigue life estimation
- Small-bubble gas injection
- Spallation Neutron Source
- Strain reduction
- Structural analysis
- Target vessel