Mechanical design of SXLS radio-frequency cavity

The mechanical design of an all-copper RF cavity for the Superconducting X-ray Lithography Source (SXLS) is described. The design has been optimized for space and functional requirements by analytical studies using Superfish and ANSYS computer programs. Resonance frequency variation due to thermal deformations is minimized by water channels machined onto the main structure. The effects of pressure deformations, residual thermal deflections, and mechanical tolerances are compensated by adjusting the gap size through step machining of the drift tube nose which is separable from the main body. An ultrahigh vacuum is achieved by pumping through conical vacuum port with a 220-l/s ion pump. The design provides for a tuner to compensate for the frequency drift under thermal and reactive beam loads during the operation, and antennas for the suppression of higher-order modes. Multipactoring effects are controlled by sputtering the cavity with titanium and backfilling it with dry nitrogen.<
>