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Wu, Q.

Paper Title Page
TUPMS089 Thermal Emittance Measurement Design for Diamond Secondary Emission 1374
  • Q. Wu, I. Ben-Zvi, A. Burrill, X. Chang, D. Kayran, T. Rao, J. Smedley
    BNL, Upton, Long Island, New York
  Thermal emittance is a very important characteristic of cathodes. A lower thermal emittance cathode has a better performance in limiting emittance for transport down the beam line. A diamond amplified photocathode, being a negative electron affinity (NEA) cathode, promises to deliver a very small thermal emittance. A carefully designed method of measuring the emittance of secondary emission from diamond is presented for the first time. Comparison of possible schemes is carried out by simulation, and the most accessible and accurate method and values are chosen. Systematic errors can be controlled within a very small range, and are carefully evaluated. Aberration and limitations of all equipment are taken into account.  
TUPMS076 Status of R&D Energy Recovery Linac at Brookhaven National Laboratory 1347
  • 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
  Funding: Work performed under the auspices of the U. S. Department of Energy and partially funded by the US Department of Defence.

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.

WEOCKI03 Status of the R&D Towards Electron Cooling of RHIC 1938
  • 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
  Funding: Work done under the auspices of the US DOE with support from the US DOD.

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.

slides icon Slides  
WEOCC04 Recent Progress on the Diamond Amplified Photo-cathode Experiment 2044
  • X. Chang, I. Ben-Zvi, A. Burrill, J. G. Grimes, T. Rao, Z. Segalov, J. Smedley
    BNL, Upton, Long Island, New York
  • Q. Wu
    IUCF, Bloomington, Indiana
  We report recent progress on the Diamond Amplified Photo-cathode (DAP). The use of a pulsed electron gun provides detailed information about the DAP physics. The secondary electron gain has been measured under various electric fields. We have achieved gains of a few hundred in the transmission mode and observed evidence of emission of electrons from the surface. A model based on recombination of electrons and holes during generation well describes the field dependence of the gain. The emittance measurement system for the DAP has been designed, constructed and is ready for use. The capsule design of the DAP is also being studied in parallel.  
slides icon Slides  
THPAS020 3D Simulations of Secondary Electron Generation and Transport in a Diamond Amplifier for Photocathodes 3555
  • D. A. Dimitrov, D. L. Bruhwiler, R. Busby, J. R. Cary
    Tech-X, Boulder, Colorado
  • I. Ben-Zvi, X. Chang, T. Rao, J. Smedley, Q. Wu
    BNL, Upton, Long Island, New York
  The Relativistic Heavy Ion Collider (RHIC) contributes fundamental advances to nuclear physics by colliding a wide range of ions. A novel electron cooling section, which is a key component of the proposed luminosity upgrade for RHIC, requires the acceleration of high-charge electron bunches with low emittance and energy spread. A promising candidate for the electron source is the recently developed concept of a high quantum efficiency photoinjector with a diamond amplifier. We have started to implement algorithms, within the VORPAL particle-in-cell framework, for modeling of secondary electron and hole generation, and for charge transport in diamond. The algorithms include elastic and various inelastic scattering processes over a wide range of charge carrier energies. Initial results from the implemented capabilities will be presented and discussed.

The work at Tech-X Corp. is supported by the U. S. Department of Energy under a Phase I SBIR grant.