Speaker
Description
At the Spallation Neutron Source (SNS), the proton accumulator ring concentrates technical risk in the injection region, where the electron catcher (e-catcher) removes secondary electrons generated during H⁻ stripping to protect nearby components and maintain stable operation. Following Proton Power Upgrade (PPU) modifications, the e-catcher failed on first beam operation due to insufficient cooling capacity. Other shortcomings of the design resulted from poor interface definition and technical review practices. This incident demonstrates how small specification and unit-consistency error can propagate through design reviews and lead to installation and operational issues. The work summarizes the failure mechanism, diagnostic process, and the need for more rigorous interface definition and technical-review practices.