Author: Gassner, D.M.
Paper Title Page
MOPF31 Design and Performance of the Biased Drift Tube System in the BNL Electron Lens 291
  • T.A. Miller, W. Fischer, D.M. Gassner, X. Gu, A.I. Pikin, S. Polizzo, P. Thieberger
    BNL, Upton, Long Island, New York, USA
  • J. Barth
    Barth Electronics, Boulder City, USA
  Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy.
The installation of the Electron Lenses in RHIC will be completed this year. Its design includes a series of drift tubes through which the electron beam copropagates, with the RHIC proton beams. These drift tubes are used to create an electric field gradient to sweep out ions that become trapped within the central magnetic field where the electron beam interacts with the proton beams. These isolated drift tubes are biased by high voltage power supplies. Without a path for the proton beam image currents, high voltages will develop on the drift tubes that can be detrimental to the electron beam and increase the RHIC machine impedance. This paper presents the design of the drift tubes, axial electric field gradient, and the custom high voltage RF bias tees that were designed to provide separate paths for the high frequency image currents and the DC high voltage bias over the same cables. The design and simulation of the bias tee is discussed, as well as RF signals from the proton beam current imaged on the drift tubes, as measured through the bias tees during the commissioning of the blue RHIC beam electron lens this past spring.
poster icon Poster MOPF31 [31.237 MB]  
TUPF01 Proton Emittance Measurements in the Brookhaven AGS 492
  • H. Huang, R. Connolly, C.W. Dawson, D.M. Gassner, C.E. Harper, S.E. Jao, W. Meng, F. Méot, R.J. Michnoff, M.G. Minty, V. Schoefer, T. Summers, S. Tepikian, K. Yip, K. Zeno
    BNL, Upton, Long Island, New York, USA
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
High luminosity and high polarization in RHIC require good control and measurement of emittance in its injector, the Brookhaven AGS. In the past, the AGS emittance has been measured by using an ion collecting IPM during the whole cycle and a multi-wire at injection. The beam profiles from this IPM are distorted by space charge forces at higher energy, which makes the emittance determination very hard. In addition, helical superconducting snake magnets and near integer vertical tune for polarized proton operation distort the lattice in the AGS and introduce large beta beating. For more precise measurements of the emittance, we need TBT measurements near injection and beta function measurements at the location of devices used to measure the emittance. A Polarimeter target has been used as flying wire for proton emittance measurement. A new type electron collecting IPM has been installed and tested in the AGS with proton beam. The Beta functions at the IPM locations have been measured with Orbit Response Matrix (ORM) methods and with a local corrector at IPM. This paper summarizes our current understanding of AGS emittances and plans for further improvements.
TUPF24 Instrumentation for the Proposed Low Energy RHIC Electron Cooling Project 561
  • D.M. Gassner, A.V. Fedotov, D. Kayran, V. Litvinenko, R.J. Michnoff, T.A. Miller, M.G. Minty, I. Pinayev, M. Wilinski
    BNL, Upton, Long Island, New York, USA
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy
There is a strong interest in running RHIC at low ion beam energies of 2.5-20GeV/nucleon; this is much lower than the typical operations with 100GeV/nucleon. The primary motivation for this effort is to explore the existence and location of the critical point on the QCD phase diagram. Electron cooling can increase the average integrated luminosity and increase the length of the stored lifetime. Simulations and conceptual cooling sub-system designs are underway. The present plan is to provide 10–50mA of bunched electron beam with adequate quality and an energy range of 0.9–5MeV. The preliminary cooling facility configuration planned to be fully inside the RHIC tunnel will include a 102.74MHz SRF gun, a booster cavity, a beam transport to the Blue ring to allow electron-ion co-propagation for ~10-20m, then a 180 degree u-turn electron transport so the same electron beam can similarly cool the Yellow ion beam, then to a dump. The electron beam instrumentation systems that will be described include current transformers, BPMs, profile monitors, a pepper pot emittance station and loss monitors.
poster icon Poster TUPF24 [1.588 MB]  
WEPC03 Brookhaven 200 MeV Linear Accelerator Beam Instrumentation Upgrade 656
  • O. Gould, B. Briscoe, D.M. Gassner, V. LoDestro, R.J. Michnoff, J. Morris, D. Raparia, K. Sanders, W. Shaffer, C. Theisen, M. Wilinski
    BNL, Upton, Long Island, New York, USA
  • D. Persaud
    City College of The City University of New York, New York, USA
  The Brookhaven National Laboratory 200 MeV H LINAC beam instrumentation equipment has been in operation for four decades with various changes implemented over this period. There is a need to upgrade the entire beam instrumentation system of the LINAC to improve the diagnostics of the beam from the Low Energy Beam Transport Line through the LINAC and into the LINAC Booster Transfer Line and BLIP line. Profile Monitors, Current Monitors, Beam Position Monitors, Loss Radiation Monitors, and Emittance Measurement devices are to be designed and implemented over the next three years. This upgrade will improve the operation reliability, beam quality and beam losses. Additional improvements will be obtained by designing the beam instrumentation system to integrate with other proposed diagnostics and malfunction detection and display upgrades in the LINAC Control Room to improve the overall performance of the LINAC.  
poster icon Poster WEPC03 [18.356 MB]