A New Conical Half-Wave Superconducting Cavity

The lattice period in the low energy section of a proton accelerator is required by the physics to be as short as possible; however, the required number of beamline components per period is high. By gradually increasing the diameter of the low energy accelerating cavities (giving them a conical shape) and staggering the rotation of the cavities a considerable reduction in the space required is obtained.Conical half-wave resonator optimization to provide a reduced peak magnetic field. The resonator tuning system was designed to provide a tuning sensitivity of 10 kHz/mm. A mechanical stiffening structure was also designed. Combined analysis of the cavity with the liquid helium vessel structure with provisional supports in the cryomodule in order to confirm its electrodynamic and mechanical properties was performed. Further work will be done on refining the parameters of the conical structure. A complete engineering design of the conical half-wave resonator with helium vessel will be developed. Two conical half-wave resonators with helium vessels will be manufactured. After surface processing of the cavities, RF measurements and high-gradient tests will be performed. Commercial Applications and Other Benefits: This concept for superconducting structures will permit construction of the low energy accelerator for Project X or other high intensity machine like a spallation neutron source with a shorter lattice period and hence improved beam quality at lower cost.