• S. Barbanotti, M.H. Foley, I.G. Gonin, J. Grimm, T.N. Khabiboulline, L. Ristori, N. Solyak, V.P. Yakovlev
  Fermilab, Batavia

Project X is a proposed high-intensity proton accelerator complex that could provide beam to create a high-intensity neutrino beam, feed protons to kaon- and muon-based precision experiments, and for other applications still under investigation. The present configuration of the proton accelerator foresees a section with 650 MHz beta = 0.6 and beta = 0.9 elliptical cavities. Prototypes of single-cell 650 MHz cavities and five-cell beta = 0.9 650 MHz cavities are being designed and fabricated at Fermilab in the R&D process for Project X. This paper summarizes the design status of the beta = 0.6 and beta = 0.9 single-cell prototype cavities, and also addresses the design effort focused on the five-cell beta = 0.9 cavities.

• S. Nagaitsev, M. Popovic, G.V. Romanov, R.C. Webber, V.P. Yakovlev
  Fermilab, Batavia
• Q. Ji, D. Li, T. Schenkel, J.W. Staples, S.P. Virostek
  LBNL, Berkeley, California

A multi-MW proton facility, Project X has been proposed and currently under development at Fermilab. Project X is critical for future development of accelerator complex for future high energy physics programs in the US. In collaboration with Fermilab, LBNL is actively involved in the development and design studies of the front-end system for Project X. The front-end system would consist of H^- ion source(s), low-energy beam transport (LEBT), normal conducting CW Radio-Frequency-Quadrupole (RFQ) accelerator(s), medium-energy beam transport (MEBT), beam chopper(s) and normal conducting CW rebuncher cavities. We will review and present R&D programs and recent study progress on the front-end system of Project X. These studies may include beam dynamics simulations and concepts for LEBT, RFQ, MEBT and narrow band chopper, and preliminary conceptual designs of normal conducting CW RFQ(s) and rebuncher cavities.

• T.N. Khabiboulline, S. Barbanotti, I.G. Gonin, N. Solyak, I. Terechkine, V.P. Yakovlev
  Fermilab, Batavia

Front end of a CW linac of the Project X contains a H^- source, an RFQ, a medium energy transport line with the beam chopper, and a SC low-beta linac that accelerates H^- from 2.5 MeV to 160 MeV. SC Single ' spoke Resonators (SSR) will be used in the linac, because Fermilab already successfully developed and tested a SSR for beta 0.21. Two manufactured cavities achieve 2-3 times more than design accelerating gradients. One of these cavities completely dressed, e.g. welded to helium vessel with integrated slow and fast tuners, and tested in CW and pulse regimes. Successful tests of beta=0.21 SSR give us a confidence to use this type of cavity for low beta (0.117) and for high- beta (0.4) as well. Both types of these cavities are under development. In present report the basic constrains, parameters, electromagnetic and mechanical design for all the three SSR cavities, and first test results of beta=0.21 SSR are presented.