Design of a [Beta]=0.175 2-Gap Spoke Resonator

In this paper, we present the electromagnetic and structural design of a low-b superconducling spoke resonator for a beam-test in the Low Energy Demonstration Accelerator (LEDA). This test is part of the Advanced Accelerator Applications (AAA) project. Recently, the sole use of superconducting resonators from 6.7 MeV on has been approved for this project. The beam test will use the lowest- resonator from this accelerator design. The choices of the cavity dimensions are driven by its use imrnediately after the LEDA Radio-Frequency Quadrupole (RFQ). The frequency is 350 MHz, the lengt corresponds to a geometric p (Ps) of 0.175. Our design approach has been to carry out an integrated RF and mechanical design from the start. The final cavity is well understood in terms of IW: and mechanical properties. The RF properties, like Q, WQ, peak surface fields and acceleration efficiency are very reasonable for such a low- structure. 'The design also includes power coupler, vacuum and pick-up ports and lheir influences. The mechanical design added tuning sensitivities, tuning forces, stiffening schemes and the understanding of stresses under various load conditions. This presentation reflects changes in the coupling port and the beam aperture compared to a previously presented design.