Speaker
Description
Buffered Chemical Polishing (BCP) is one of the most widely adopted surface treatment methods for superconducting radio-frequency (SRF) cavities because of its simplicity and cost-effectiveness. However, the stationary BCP process can produce non-uniform material removal due to bubble accumulation and acid flow instability, resulting in streak patterns and localized surface roughness that may affect RF performance. To address these issues, a rotational BCP (RBCP) system was developed to promote the continuous removal of reaction bubbles during the etching process. In addition, a process temperature control system was incorporated to maintain more consistent etching conditions during surface treatment. The rotational motion and temperature control are expected to contribute to a more uniform chemical reaction over the cavity surface and reduce the formation of streak patterns. In this study, the inner surface characteristics of SRF cavities processed using the RBCP system were compared with those treated by a conventional BCP process. Vertical tests (VT) were also conducted to evaluate the RF performance after the complete cavity preparation procedure. The RBCP process showed reduced streak formation and relatively improved surface uniformity compared with the stationary BCP process. The results suggest that the combination of rotational motion and process temperature control can contribute to more consistent surface treatment of SRF cavities.