• D. T. Abell
  
• P. J. Mullowney, K. Paul, V. H. Ranjbar
  Tech-X, Boulder, Colorado
• J. Qiang, R. D. Ryne
  LBNL, Berkeley, California

The standard implementation of using FFTs to solve the Poisson equation with open boundary conditions on a Cartesian grid loses accuracy when the change in G rho (the product of the Green function and the charge density) over a mesh cell becomes nonlinear; this is commonly encountered in high aspect ratio situations and results in poor efficiency due to the need for a very large number of grid points. A modification which solves this problem, the integrated Green function (IGF), has been implemented in two dimensions using linear basis functions and in three dimensions using constant basis functions. But, until recently, it has proved to be very difficult to implement IGF in three dimensions using linear basis functions. Recently significant progress has been made. We present both the implementation and test results for the three-dimensional extension.

• 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.

• D. R. Dechow
  
• D. T. Abell, P. Stoltz
  Tech-X, Boulder, Colorado
• J. F. Amundson
  Fermilab, Batavia, Illinois
• L. Curfman McInnes, B. Norris
  ANL, Argonne, Illinois

A component-based beam dynamics application for modeling collective effects in particle accelerators has been developed. The Common Component Architecture (CCA) software infrastructure was used to compose a new Python-steered accelerator simulation from a set of services provided by two separate beam dynamics packages (Synergia and MaryLie/Impact) and two high-performance computer science packages (PETSc and FFTW). The development of the proof-of-concept application was accomplished via the following tasks:

1. addressing multilanguage interoperability in the MaryLie/Impact code with Babel;
2. creating components by making the selected software objects adhere to the Common Component Architecture protocol;
3. assemblying the components with a newly developed, Component Builder gui; and
4. characterizing the performance of the space charge (Poisson) solver that was originally used in Synergia 1.0 versus the PETSc-based space charge solver that has been developed for Synergia2.

• V. H. Ranjbar
  
• D. T. Abell, K. Paul
  Tech-X, Boulder, Colorado
• I. Ben-Zvi, J. Kewisch
  BNL, Upton, Long Island, New York
• J. Qiang, R. D. Ryne
  LBNL, Berkeley, California

Plans for the RHIC luminosity upgrade call for an electron cooling system that will place substantial demands on the energy, current, brightness, and beam quality of the electron beam. In particular, the requirements demand a new level of fidelity in beam dynamics simulations. New developments in MaryLie/IMPACT have improved the space-charge computations for beams with large aspect ratios and the beam dynamic computations for rf cavities. We present the results of beam dynamics simulations that include the effects of space charge and nonlinearities, and aim to assess the tolerance for errors and nonlinearities on current designs for a super-conducting ERL.