Design, Construction and Commissionig of a NEG Coated Wiggler Vacuum Chamber for the LNLS Storage Ring

We present the design of the vacuum chamber for the LNLS 2T Hybrid Wiggler. The chamber is a 3m long, 1.2mm thick 316L SS tube, which was mechanically pressed into an elliptical shape from an originally round tube. In order to provide the necessary mechanical tolerances, the rather flexible tube is welded to lateral supports that run the complete length of the chamber. Special care has been given to the mechanical and magnetic characterization of the chamber and the inner surface of the chamber was NEG-coated at the ESRF. We present the installation procedure as well the vacuum conditioning charge evolution.