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Henderson, S.

Paper Title Page
TUPLT168 SNS Beam Commisioning Status 1524
 
  • S. Henderson, A.V. Aleksandrov, S. Assadi, W. Blokland, C. Chu, S.M. Cousineau, V.V. Danilov, G.W. Dodson, J. Galambos, M. Giannella, D.-O. Jeon, S. Kim, L.V. Kravchuk, M.P. Stockli, E. Tanke, R.F. Welton, T.L. Williams
    ORNL/SNS, Oak Ridge, Tennessee
 
  The Spallation Neutron Source accelerator systems will provide a 1 GeV, 1.44 MW proton beam to a liquid mercury target for neutron production. The accelerator complex consists of an H- injector capable of producing 38 mA peak current, a 1 GeV linear accelerator, an accumulator ring and associated transport lines. The linear accelerator consists of a Drift Tube Linac, a Coupled-Cavity Linac and a Superconducting Linac which provide 1.5 mA average current to the accumulator ring. The staged beam commissioning of the accelerator complex is proceeding as component installation progresses. In three separate beam commissioning runs, the H- injector and Drift Tube Linac tanks 1-3 have been commissioned at ORNL. Several important performance goals have been achieved, namely 38 mA peak beam current, 1 msec beam pulse length and 1 mA average beam current. Results and status of the beam commissioning program will be presented.  
TUPLT170 The SNS Beam Power Upgrade 1527
 
  • S. Henderson, S. Assadi, R. Cutler, V.V. Danilov, G.W. Dodson, R.E. Fuja, J. Galambos, J.A. Holmes, N. Holtkamp, D.-O. Jeon, S. Kim, L.V. Kravchuk, M.P. McCarthy, G.R. Murdoch, D.K. Olsen, T.J. Shea, M.P. Stockli
    ORNL/SNS, Oak Ridge, Tennessee
 
  The Spallation Neutron Source (SNS) accelerator systems, which consist of an H- injector, a 1 GeV linear accelerator, an accumulator ring and associated transport lines, will provide a 1 GeV, 1.44 MW proton beam to a liquid mercury target for neutron production. The SNS is presently under construction at Oak Ridge National Laboratory and will begin operations in 2006. Even in the baseline design, many of the accelerator subsystems are capable of supporting higher beam intensities and higher beam energy. We report on upgrade scenarios for the SNS accelerator systems which increase the 1.44 MW baseline beam power to at least 3 MW, and perhaps as high as 5 MW. The increased SNS beam power can be achieved primarily by increasing the H- ion source current, installing additional superconducting cryomodules to increase the final linac beam energy to 1.3-1.4 GeV, and modifying injection and extraction hardware in the ring to handle the increased beam energy. The upgrade beam parameters will be presented, the required hardware modifications will be described, and the beam dynamics implications will be discussed.  
TUPLT171 ORBIT Simulations of the SNS Accumulator Ring 1530
 
  • J.A. Holmes, S.C. Bunch, S.M. Cousineau, V.V. Danilov, S. Henderson, A. Shishlo
    ORNL/SNS, Oak Ridge, Tennessee
  • M. Plum
    LANL, Los Alamos, New Mexico
  • Y. Sato
    IUCF, Bloomington, Indiana
 
  As SNS undergoes construction, many detailed questions arise concerning strategies for commissioning and operating the accumulator ring. The ORBIT Code is proving to be an indispensible tool for addressing these questions and for providing guidance to the physicists and decision makers as operation draws near. This paper shows the application of ORBIT to a number of ring issues including exclusion of the HEBT RF cavities during commissioning, the detailed effect of the injection chicane magnets on the beam, the effects and correction of magnet alignment and multipole errors, debunching of the linac 402.5 MHz beam structure, the injection of self consistent uniform beam configurations, and initial electron cloud simulations.  
TUPLT186 Managing System Parameters for SNS Magnets and Power Supplies 1565
 
  • W.J. McGahern, S. Badea, F.M. Hemmer, H.-C. Hseuh, J.W. Jackson, A.K. Jain, F.X. Karl, R.F. Lambiase, Y.Y. Lee, C.J. Liaw, H. Ludewig, G.J. Mahler, W. Meng, C. Pai, C. Pearson, J. Rank, D. Raparia, J. Sandberg, S. Tepikian, N. Tsoupas, J. Tuozzolo, P. Wanderer, J. Wei, W.-T. Weng
    BNL, Upton, Long Island, New York
  • R. Cutler, J.J. Error, J. Galambos, M.P. Hechler, S. Henderson, P.S. Hokik, T. Hunter, G.R. Murdoch, K. Rust, J.P. Schubert
    ORNL/SNS, Oak Ridge, Tennessee
 
  The Spallation Neutron Source (SNS), currently under construction at Oak Ridge, Tennessee, is a collaborative effort of six U.S. Department of Energy partner laboratories. With over 312 magnets and 251 power supplies that comprise the beam transport lines and the accumulator ring, it is a challenge to maintain a closed loop on the variable parameters that are integral to these two major systems. This paper addresses the input variables, responsibilities and design parameters used to define the SNS magnet and power supply systems.  
WEPLT170 Injection Schemes for Self Consistent Space Charge Distributions 2224
 
  • V.V. Danilov, S.M. Cousineau, S. Henderson, J.A. Holmes, M. Plum
    ORNL/SNS, Oak Ridge, Tennessee
 
  This paper is based on recently found sets of self-consistent 2D and 3D time-dependent space charge distributions. A subset of these distributions can be injection-painted into an accumulator ring, such as Spallation Neutron Source Ring, to produce periodic space charge conditions. The periodic condition guarantees zero space-charge-induced halo growth and beam loss during injection. Practical aspects of such schemes are discussed, and simulations of a few specific cases are presented.  
WEPLT172 Design & Handling of High Activity Collimators &Ring Components on the SNS 2230
 
  • G.R. Murdoch, D. Crisp, S. Henderson, M. Holding, K. Potter, T. Roseberry
    ORNL/SNS, Oak Ridge, Tennessee
 
  Design & Handling of High Activity Collimators on the SNS*G Murdoch,S Henderson, K Potter,T Roseberry,Oak Ridge National Laboratory, USA,H Ludewig, N Simos, Brookhaven National Laboratory, USAJ Hirst, Rutherford Appleton Laboratory,UK, The Spallation Neutron Source accelerator systems will provide a 1GeV, 1.44MW proton beam to a liquid mercury target for neutron production. The expected highest doses to components are in the collimator regions. This paper presents the mechanical engineering design of a typical collimator highlighting the design features incorporated to assist with removal once it is activated. These features include shielding and lifting fixtures but more importantly a double contained flexible water system incorporating remote water couplings.Also presented is a mechanism that allows axial removal of vacuum bellows and its associated vacuum clamps.*SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos and Oak Ridge.  
THPLT166 Development of Injection and Optics Control Applications for the SNS Accumulator Ring 2846
 
  • S.M. Cousineau, C. Chu, J. Galambos, S. Henderson, T. Pelaia, M. Plum
    ORNL/SNS, Oak Ridge, Tennessee
  • A.L. Leahman
    WSSU, Winston-Salem, North Carolina
 
  A large suite of physics software applications is being developed to facilitate beam measurement and control in the SNS accumulator ring. Two such applications are an injection control and measurement application, and a ring optics control application. The injection application will handle measurement and control of the linac beam position and angle at the stripper foil, and will be used to measure the twiss parameters of the linac beam at the foil. The optics control application will provide knobs for machine working point, chromaticity, arc phase advance, and harmonic correction. Both applications are written within the standard in-house XAL framework. Presented here are first versions of the applications, along with plans for future development and testing.  
THPLT167 SNS Laser Profile Monitor Progress 2849
 
  • W. Blokland, A.V. Aleksandrov, S. Assadi, C. Deibele, W. Grice, S. Henderson, T. Hunter, P. Ladd, G.R. Murdoch, J. Pogge, K. Potter, T.J. Shea, D. Stout
    ORNL/SNS, Oak Ridge, Tennessee
  • V. Alexandrov
    BINP SB RAS, Protvino, Moscow Region
 
  SNS will use a Nd:YAG laser to measure transverse profiles in the 186-1000 MeV super-conducting LINAC (SCL) and Ti:Sapphire modelock laser to measure longitudinal profiles in the 2.5 MeV Medium Energy Beam Transport (MEBT). The laser beam is scanned across the H- beam to photo-neutralize narrow slices. The liberated electrons are collected to provide a direct measurement of the transverse or longitudinal beam profile. We have successfully measured the transverse profile with a prototype system on the MEBT beam. The final SCL system uses an optical transport line that is installed alongside the 300 meter super-conducting LINAC to deliver laser light at 8 locations. Possible vibrations in the optical transport system can lead to inaccuracies in the profile measurement. We will use an active feedback system on a mirror to correct any vibration up to 2 KHz. In this paper we describe our vibration studies and vibration cancellation system as well as the progress in the design, installation and testing of various subsystems for both the transverse and the longitudinal profiles.