• S. Boucher, R.B. Agustsson, P. Frigola, A.Y. Murokh, M. Ruelas
  RadiaBeam, Marina del Rey
• F.H. O'Shea, J.B. Rosenzweig, G. Travish
  UCLA, Los Angeles, California

The fixed-field alternating-gradient (FFAG) betatron has emerged as a viable alternative to RF linacs as a source of high-energy radiation for industrial and security applications. RadiaBeam Technologies is currently developing an FFAG betatron with a novel induction core made with modern low-loss magnetic materials. The principle challenge in the project has been the design of the magnets. In this paper, we present the current status of the project, including results of the magnet design and testing.

• P. Frigola, R.B. Agustsson, S. Boucher, A.Y. Murokh
  RadiaBeam, Marina del Rey
• H. Badakov, A. Fukasawa, P. Musumeci, J.B. Rosenzweig, G. Travish
  UCLA, Los Angeles, California
• D. Cormier, T. Mahale
  NCSU, Raleigh, North Carolina
• L. Faillace
  INFN/LNF, Frascati (Roma)

Electron beam based additive fabrication techniques have been successfully applied to produce a variety of complex, fully dense, metal structures. These methods, collectively known as Solid Freeform Fabrication (SFF) are now being explored for use in radio frequency (RF) structures. SFF technology may make it possible to design and produce near-netshape copper structures for the next generation of very high duty factor, high gradient RF photoinjectors. The SFF process discussed here, Arcam Electron Beam Melting (EBM), utilizes an electron beam to melt metal powder in a layer-by-layer fashion. The additive nature of the SFF process and its ability to produce fully dense parts are explored for the fabrication of internal cooling passages in RF photoinjectors. Following an initial feasibility study of the SFF process, we have fabricated a copper photocathode, suitable as a drop-in replacement for the UCLA 1.6 cell photoinjector, with internal cooling channels using SFF. Material analysis of the prototype cathode and new designs for a high duty factor photoinjector utilizing SFF technology will be presented.

• A.Y. Murokh, R.B. Agustsson, P. Frigola
  RadiaBeam, Marina del Rey
• V. Solovyov
  BNL, Upton, Long Island, New York

Funding: DOE

A High Temperature Superconducting Dysprosium Pole Undulator (HTS-DPU) is proposed to achieve an ultra-high peak field in a very short period undulator structure. This design utilizes the unique ferromagnetic properties of dysprosium (Dy) at liquid nitrogen temperature. The fabrication of textured Dy fabricated via economic and highly reproducible process is studied experimentally with the goal to achieve sufficient magnetic anisotropy and desired field saturation level at a practical cost. In addition, utilizing the latest capabilities of the 2G HTS wire is investigated. The practical implementation of HTS-DPU would enable the development of short period insertion devices with superior performance.