Author: Mustapha, B.
Paper Title Page
MOODS5 3D Electromagnetic Design and Beam Dynamics Simulations of a Radio-Frequency Quadrupole 97
 
  • B. Mustapha, A. Kolomiets, P.N. Ostroumov
    ANL, Argonne, USA
  
  Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.
During the design of the 60.635 MHz RFQ for the ATLAS efficiency and intensity upgrade*, we have established a new full 3D approach for the electromagnetic and beam dynamics simulations of a RFQ. A Detailed full 3D model (four meter long) including vane modulation was built and simulated using CST Microwave Studio, which is made possible by the ever advancing computing capabilities. The approach was validated using experimental measurements on a prototype 57.5 MHz RFQ**. The effects of the radial matchers, vane modulation and tuners on the resonant frequency and field flatness have been carefully studied. The full 3D field distribution was used for beam dynamics simulations using both CST Particle Studio and the beam dynamics code TRACK***. In the final design we have used trapezoidal modulation instead of the standard sinusoidal in the accelerating section of the RFQ to achieve more energy gain for the same length, following the leading work of the Protvino group****. In our case, the output energy increased from 260 keV/u to 295 keV/u with minimal change in the beam dynamics.
* P.N. Ostroumov et al, Proceedings of LINAC-2010
** P.N. Ostroumov et al, Proceedings of LINAC-2006
*** TRACK @ http://www.phy.anl.gov/atlas/TRACK
**** O.K. Belyaev et al, Proceedings of LINAC-2000
 		 
slides icon Slides MOODS5 [2.531 MB]  
 
TUP044 A Comparison of Superconducting RF Structures Optimized for β = 0.285 889
 
  • Z.A. Conway, R.L. Fischer, M.P. Kelly, A. Kolomiets, B. Mustapha, P.N. Ostroumov
    ANL, Argonne, USA
  
  Recent advances in low-beta superconducting RF technology have enabled the proposal and construction of ever-increasing-intensity ion accelerators, e.g. The Facility for Rare Isotope Beams (FRIB) at Michigan State University and Project-X at Fermilab. Superconducting TEM-class structures are required for these accelerators and beam quality preservation and cost efficiency are of the highest importance. This paper presents a comparison of the superconducting TEM-class cavities available for the acceleration of ions in the energy range of 16 to 55 MeV/u in order to guide their selection in future ion accelerator projects.  
 
WEP091 Implementation of H− Intrabeam Stripping into TRACK 1642
 
  • J.-P. Carneiro
    Fermilab, Batavia, USA
  • B. Mustapha, P.N. Ostroumov
    ANL, Argonne, USA
  
  H− intrabeam stripping has been presented* as potentially harmful to MW scale H− linacs. If not taken properly into account, intrabeam stripping of the H− beam could lead to losses in excess of the 1 W/m limit and result in non-tolerable beamline elements activation. This paper describes the implementation of the H− intrabeam stripping effect into the beam dynamics code TRACK**. Simulations results and numerical applications will be presented for the SNS linac and the FNAL ProjectX.
* V. Lebedev, "Intrabeam Stripping in H− Linacs", LINAC2010
** P. Ostroumov, "TRACK, The Beam Dynamics Code", PAC2005 		 
 
WEP138 Developing Software Packages for Electromagnetic Simulations 1740
 
  • J. Xu, M. Min, B. Mustapha
    ANL, Argonne, USA
  
  Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.
In addition to previous developments on parallel beam dynamics software packages, our efforts have been extended to electromagnetic simulations. These efforts include developing new software packages solving the Maxwell equations in 2D and 3D. Scalable algorithms have been used for use of ALCF supercomputers. These new solvers are based on high order numerical methods. Comparative studies of structured and unstructured grids, continuous and discontinuous Galerkin methods will be discussed. The effects of bases will also be presented. Efficiency and challenges of new software packages will be presented. Some benchmarking and simulation results will be shown. 		 
 
THOCN5 ATLAS Upgrade 2110
 
  • P.N. Ostroumov, A. Barcikowski, Z.A. Conway, S.M. Gerbick, M. Kedzie, M.P. Kelly, S.W.T. MacDonald, B. Mustapha, R.C. Pardo, S.I. Sharamentov
    ANL, Argonne, USA
  
  Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.
ATLAS (Argonne Tandem Linac Accelerator System) upgrade requires several substantial developments in accelerator technologies, such as CW heavy ion RFQ and high-performance cryomodule with low-beta cavities. The upgrade project is well advanced. The physics and engineering design of the RFQ are complete and fabrication of OFE copper parts is in progress. The 3.9-meter length RFQ is composed from 5 strongly coupled segments. High-temperature furnace brazing of the segments is planned for the summer of 2011. The RFQ design includes several innovative features such as trapezoidal vane tip modulation, compact output radial matcher to form an axially symmetric beam. The upgrade project also includes development and construction of a cryomodule containing seven 72.75 MHz SC quarter wave cavities designed for the geometrical β= 0.077 and four SC solenoids. The cavity is designed to obtain an accelerating voltage higher than 2.5 MV. The prototype cavity together with high-power capacitive coupler and piezoelectric tuner has been developed, fabricated and is being tested. This paper reports innovative design features of both RFQ and SRF linac and current status of the project. 		 
slides icon Slides THOCN5 [3.070 MB]