• T. Russo
  
• S. Bellavia, D. M. Gassner, P. Thieberger, D. Trbojevic, T. Tsang
  BNL, Upton, Long Island, New York

A hydrogen jet polarimeter was developed for the RHIC accelerator to improve the process of measuring polarization. Particle beams intersecting with gas molecules can produce light by the process known as luminescence. This light can then be focused, collected, and processed giving important information such as size, position, emittance, motion, and other parameters. The RHIC hydrogen jet polarimeter was modified in 2005 with specialized optics, vacuum windows, light transport, and camera system making it possible to monitor the luminescence produced by polarized protons intersecting the hydrogen beam. This paper will describe the configuration and preliminary measurements taken using the RHIC hydrogen jet polarimeter as a luminescence monitor.

• V. Litvinenko
  
• J. Alduino, D. Beavis, I. Ben-Zvi, M. Blaskiewicz, J. M. Brennan, A. Burrill, R. Calaga, P. Cameron, X. Chang, K. A. Drees, G. Ganetis, D. M. Gassner, J. G. Grimes, H. Hahn, L. R. Hammons, A. Hershcovitch, H.-C. Hseuh, A. K. Jain, D. Kayran, J. Kewisch, R. F. Lambiase, D. L. Lederle, C. Longo, G. J. Mahler, G. T. McIntyre, W. Meng, T. C. Nehring, B. Oerter, C. Pai, D. Pate, D. Phillips, E. Pozdeyev, T. Rao, J. Reich, T. Roser, T. Russo, Z. Segalov, J. Smedley, K. Smith, J. E. Tuozzolo, G. Wang, D. Weiss, N. Williams, Q. Wu, K. Yip, A. Zaltsman
  BNL, Upton, Long Island, New York
• H. Bluem, M. D. Cole, A. J. Favale, D. Holmes, J. Rathke, T. Schultheiss, A. M.M. Todd
  AES, Princeton, New Jersey
• B. W. Buckley
  CLASSE, Ithaca
• G. Citver
  Stony Brook University, StonyBrook
• J. R. Delayen, L. W. Funk, H. L. Phillips, J. P. Preble
  Jefferson Lab, Newport News, Virginia

In this paper we present status and plans for the 20-MeV R&D energy recovery linac, which is under construction at Collider Accelerator Department at BNL. The facility is based on high current (up to 0.5 A of average current) super-conducting 2.5 MeV RF gun, single-mode super-conducting 5-cell RF linac and about 20-m long return loop with very flexible lattice. The R&D ERL, which is planned for commissioning in 2008, aims to address many outstanding questions relevant for high current, high brightness energy-recovery linacs.

• I. Ben-Zvi
  
• 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
• 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
• 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.