• S. A. Kahn, M. Alsharo'a, R. P. Johnson, M. Kuchnir
  Muons, Inc, Batavia
• R. C. Gupta, R. B. Palmer, P. Wanderer, E. Willen
  BNL, Upton, Long Island, New York
• D. J. Summers
  UMiss, University, Mississippi

The ability of high temperature superconducting (HTS) conductor to carry high currents at low temperatures makes feasible the development of very high field magnets for uses in accelerators and beam-lines. A specific application of a very high field solenoid is to provide a very small beta region for the final cooling stages for a muon collider. This paper will describe a conceptual design of a 50 Tesla solenoid based on Bi-2223 HTS tape, where the magnet will be operated at 4.2 K to take advantage of the high current carrying capacity at that temperature. A 25 Tesla solenoid has been run using a 5 Tesla Bi-2212 insert. The current carrying capacity of the BSCCO wire has been measured to be 266 Amps/mm2 at 4.2 K at the NHFML. This paper will describe the technical issues associated with building this 50 Tesla magnet. In particular it will address how to mitigate the large Lorentz stresses associated with the high field magnet and how to design the magnet to reduce the compressive end forces.

• I. Ben-Zvi, J. Alduino, D. S. Barton, D. Beavis, M. Blaskiewicz, J. M. Brennan, A. Burrill, R. Calaga, P. Cameron, X. Chang, K. A. Drees, A. V. Fedotov, W. Fischer, G. Ganetis, D. M. Gassner, J. G. Grimes, H. Hahn, L. R. Hammons, A. Hershcovitch, H.-C. Hseuh, D. Kayran, J. Kewisch, R. F. Lambiase, D. L. Lederle, V. Litvinenko, C. Longo, W. W. MacKay, G. J. Mahler, G. T. McIntyre, W. Meng, B. Oerter, C. Pai, G. Parzen, D. Pate, D. Phillips, S. R. Plate, E. Pozdeyev, T. Rao, J. Reich, T. Roser, A. G. Ruggiero, T. Russo, C. Schultheiss, Z. Segalov, J. Smedley, K. Smith, T. Tallerico, S. Tepikian, R. Than, R. J. Todd, D. Trbojevic, J. E. Tuozzolo, P. Wanderer, G. Wang, D. Weiss, Q. Wu, K. Yip, A. Zaltsman
  BNL, Upton, Long Island, New York
• D. T. Abell, G. I. Bell, D. L. Bruhwiler, R. Busby, J. R. Cary, D. A. Dimitrov, P. Messmer, V. H. Ranjbar, D. S. Smithe, A. V. Sobol, P. Stoltz
  Tech-X, Boulder, Colorado
• A. V. Aleksandrov, D. L. Douglas, Y. W. Kang
  ORNL, Oak Ridge, Tennessee
• H. Bluem, M. D. Cole, A. J. Favale, D. Holmes, J. Rathke, T. Schultheiss, J. J. Sredniawski, A. M.M. Todd
  AES, Princeton, New Jersey
• A. V. Burov, S. Nagaitsev, L. R. Prost
  Fermilab, Batavia, Illinois
• Y. S. Derbenev, P. Kneisel, J. Mammosser, H. L. Phillips, J. P. Preble, C. E. Reece, R. A. Rimmer, J. Saunders, M. Stirbet, H. Wang
  Jefferson Lab, Newport News, Virginia
• V. V. Parkhomchuk, V. B. Reva
  BINP SB RAS, Novosibirsk
• A. O. Sidorin, A. V. Smirnov
  JINR, Dubna, Moscow Region

The physics interest in a luminosity upgrade of RHIC requires the development of a cooling-frontier facility. Detailed cooling calculations have been made to determine the efficacy of electron cooling of the stored RHIC beams. This has been followed by beam dynamics simulations to establish the feasibility of creating the necessary electron beam. Electron cooling of RHIC at collisions requires electron beam energy up to about 54 MeV at an average current of between 50 to 100 mA and a particularly bright electron beam. The accelerator chosen to generate this electron beam is a superconducting Energy Recovery Linac (ERL) with a superconducting RF gun with a laser-photocathode. An intensive experimental R&D program engages the various elements of the accelerator: Photocathodes of novel design, superconducting RF electron gun of a particularly high current and low emittance, a very high-current ERL cavity and a demonstration ERL using these components.