Replacement of the TPS Bending Chamber with an On-Site Cutting Method

To minimize the impact on the machine downtime due to replacement of a TPS bending chamber, an on-site cutting method had been developed. This method can shorten the replacement time of a bending chamber from 50 to 4 days and avoid breaking the vacuum in the frond ends and adjacent insertion devices. We also developed a plug to prevent micro dust, generated from saw-cutting of the vacuum chamber, contaminating the beam duct. Three different preconditioning methods, including baking, prebaking and no-bake treatments, were applied to the newly installed arc-cell vacuum systems to evaluate their efficacy on reducing the photon stimulated desorption (PSD) in the vacuum chambers. The PSD data show no obvious discrepancy between these preconditioning methods.