A   B   C   D   E   F   H   I   K   L   O   P   Q   R   S   T   V    

lattice

Paper Title Other Keywords Page
TUAX01 Accumulation of High Intensity Beam and First Observations of Instabilities in the SNS Accumulator Ring* impedance, kicker, extraction, electron 59
 
  • V. V. Danilov, A. V. Aleksandrov, S. Assadi, W. Blokland, S. M. Cousineau, C. Deibele, S. Henderson, J. A. Holmes, M. A. Plum, A. P. Shishlo
    ORNL, Oak Ridge, Tennessee
  The Spallation Neutron Source accumulator ring, designed to accumulate up to 1.5·1014 protons per pulse, was commissioned in January of 2006. During the run, over 1.·1014 protons were accumulated in the ring in the natural chromaticity state without any sign of instabilities. The first beam instabilities were observed for a high intensity coasting beam with zero chromaticity. Preliminary analysis of data indicates instabilities related to extraction kicker impedances, and electron-proton instability. Here we review the background theory and design philosophy of the ring, as it relates to instabilities, and compare the pre-commissioning predictions with the experimental measurements.  
 
TUBY02 Physics Design of a Multi-GeV Superconducting H-minus Linac linac, focusing, rfq, proton 134
 
  • P. N. Ostroumov
    ANL, Argonne, Illinois
  • G. Apollinari, G. W. Foster, R. C. Webber
    Fermilab, Batavia, Illinois
  We discuss design of a pulsed linac based on 430 independently phased superconducting resonators for acceleration of 40 mA peak current H-minus beam up to 8-GeV. Most of the voltage gain (from ~410 MeV to 8 GeV) is provided by ILC cavities and squeezed ILC-style cavities operating at 1300 MHz. Significant cost savings are expected from the use of an rf power fan out from high-power klystrons to multiple cavities. The front end of the linac operating at 325 MHz will be based on multiple-spoke cavities. A room temperature section comprised of a conventional RFQ and 16 short normal conducting H-type resonators is proposed for the initial acceleration of an H-minus or proton beam up to 10 MeV. We have developed an accelerator lattice which satisfies the beam physics and engineering specifications.  
 
TUBY05 A HIGH ENERGY GAIN DEUTERON LINAC linac, simulation, rfq, emittance 156
 
  • J. Rodnizki, D. Berkovits, K. Lavie, A. Shor, Y. Yanai
    Soreq NRC, Yavne
  The beam dynamic simulation of the SARAF 40 MeV, 4 mA deuteron beam superconducting linac is extended in this work to 90 MeV for the EURISOL driver. It is designed for a high energy gain gradient with a moderate emittance growth, based on an end-to-end 3D simulation using a detailed 40 k macro particles distribution at the RFQ exit. The linac consists of 84 superconducting HWRs and one superconducting solenoid per two HWRs. The result average energy gain is 2.0 MeV/m. At the linac first cryomodule, where the  mismatch is high, the emittance growth is controlled by considering the bunch acceleration phase at each of the HWR coupled acceleration gaps.  
 
WEAX05 Space-Charge Beam Physics Research at the University of Maryland Electron Ring (UMER)* space-charge, quadrupole, dipole, injection 218
 
  • S. Bernal, B. L. Beaudoin, D. W. Feldman, R. Feldman, R. B. Fiorito, T. F. Godlove, I. Haber, R. A. Kishek, P. G. O'Shea, C. Papadopoulos, B. Quinn, D. Stratakis, K. Tian, C. Tobin, M. Walter
    IREAP, College Park, Maryland
  • M. Reiser
    University Maryland, College Park, Maryland
  • D. F. Sutter
    HENP, SW Washington
  The University of Maryland electron ring (UMER) is a low-energy, high current recirculator for beam physics research with relevance to any applications that rely on intense beams of high quality. We review the space-charge physics issues, experimental and computational investigations, which are currently being conducted at the UMER facility. The physics issues cover a broad range, but we focus on transverse beam dynamics: halo formation, strongly asymmetric beams, Montague resonances, equipartitioning, etc. Furthermore, we report on recent developments in experiments, simulations, and improved diagnostics for space-charge dominated beams.  
 
WEBY03 Experimental studies of IBS in RHIC and comparison with theory emittance, ion, simulation, coupling 259
 
  • A. V. Fedotov, W. Fischer, S. Tepikian, J. Wei
    BNL, Upton, Long Island, New York
  A high-energy electron cooling system is presently being developed to overcome emittance growth due to Intra-beam Scattering (IBS) for heavy ion operation in RHIC. A critical item for choosing appropriate parameters of the cooler is an accurate description of the IBS. The analytic models were verified vs dedicated IBS measurements. Analysis of the 2004 data with the Au ions showed very good agreement for the longitudinal growth rates but significant disagreement with exact IBS models for the transverse growth rates. Experimental measurements were improved for the 2005 run with the Cu ions. Here, we present comparison of the 2005 data with theoretical models.  
 
THAY03 Challenges for hadron (and leptons) nonscaling FFAGs acceleration, proton, betatron, resonance 303
 
  • A. G. Ruggiero
    BNL, Upton, Long Island, New York
  The concept of Fixed-Field Alternating-Gradient (FFAG) accelerators was introduced about a half century ago. Few prototypes were built soon after and successfully placed in operation. Nevertheless, because of the perceived complexity of the early model magnets and design, the concept was soon abandoned in favor of cyclotrons, synchrotrons and linacs. It was subsequently occasionally revived for possible application as spallation neutron sources; but it was only recently that, because of the need of fast acceleration of muons, that FFAGs were re-considered and studied with more attention. Two prototypes were eventually built and operated at KEK for the acceleration of Protons. The interest indeed soon switched more steadily toward acceleration of protons (and electrons) as application for high-power proton drivers and medical accelerators. The paper describes the design procedure of a proton FFAG accelerator that employs a Non-Scaling lattice and exposes the main inherent issues, namely: the crossing of multiple resonances, space-charge at injection, and the fast acceleration rate that may impose limitations on the RF cavity hardware.  
 
THBZ05 The SNS linac commissioning – comparison of measurement and model* optics, simulation, emittance, linac 353
 
  • D.-O. Jeon
    ORNL, Oak Ridge, Tennessee
  The Spallation Neutron Source linac commissioning was an excellent opportunity to benchmark the model with the measurement data for a high intensity linac. A new halo formation mechanism due to large beam eccentricity predicted by simulation was confirmed through a series of emittance measurement. Also the phase scan technique and the acceptance scan technique were benchmarked. Commissioning both demonstrated the validity of the model and revealed the shortfall of the model.