| Paper |
Title |
Page |
| TUZBC02 |
SciDAC Frameworks and Solvers for Multi-physics Beam Dynamics Simulations
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894 |
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- J. F. Amundson, P. Spentzouris
Fermilab, Batavia, Illinois
- D. R. Dechow
Tech-X, Boulder, Colorado
- J. Qiang, R. D. Ryne
LBNL, Berkeley, California
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The need for realistic accelerator simulations is greater than ever before due to the needs of design projects such as the ILC and optimization for existing machines. Sophisticated codes utilizing large-scale parallel computing have been developed to study collective beam effects such as space charge, electron cloud, beam-beam, etc. We will describe recent advances in the solvers for these effects and plans for enhancing them in the future. To date the codes have typically applied to a single collective effect and included just enough of the single-particle dynamics to support the collective effect at hand. We describe how we are developing a framework for realistic multi-physics simulations, i.e., simulations including the state-of-the-art calculations of all relevant physical processes.
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Slides
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| TUODC02 |
Development of 3D Beam-Beam Simulation for the Tevatron
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905 |
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- E. G. Stern, J. F. Amundson, P. Spentzouris, A. Valishev
Fermilab, Batavia, Illinois
- J. Qiang, R. D. Ryne
LBNL, Berkeley, California
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We present status of development of a 3D Beam-Beam simulation code. The essential features of the code are 3D particle-in-cell Poisson solver, multi-bunch beam transport and interaction, chromaticity and machine impedance. The simulations match synchro-betatron oscillations measured at the VEPP-2M collider. The impedance model is compared to analytic expressions for instability growth.
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Slides
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| TUPMN114 |
Simulation of the Microbunching Instability in Beam Delivery Systems for Free Electron Lasers
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1179 |
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- I. V. Pogorelov, J. Qiang, R. D. Ryne, M. Venturini, A. Zholents
LBNL, Berkeley, California
- R. L. Warnock
SLAC, Menlo Park, California
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In this paper, we examine the growth of the microbunching instability in the chain of linac sections and bunch compressor chicanes used in the electron beam delivery system of a free electron laser. We compare the results of two sets of simulations, one conducted using a direct Vlasov solver, the other using a particle-in-cell code Impact-Z with the number of simulation macroparticles ranging up to 100 million. The comparison is focused on the values of uncorrelated (slice) energy spread at different points in the lattice. In particular, we discuss the interplay between physical and numerical noise in particle-based simulations, and assess the agreement between the simulation results and theoretical predictions.
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| THPAS007 |
Parallel Beam Dynamics Simulation Tools for Future Light Source Linac Modeling
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3522 |
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- R. D. Ryne, I. V. Pogorelov, J. Qiang
LBNL, Berkeley, California
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Large-scale modeling on parallel computers is playing an increasingly important role in the design of future light sources. Such modeling provides a means to accurately and efficiently explore issues such as limits to beam brightness, emittance preservation, the growth of instabilities, etc. Recently the IMPACT codes suite was enhanced to be applicable to future light source design. Early simulations with IMPACT-Z were performed using up to 100M simulation particles for the main linac of a future light source. Combined with the time domain code IMPACT-T, it is now possible to perform large-scale start-to-end linac simulations for future sources, including the injector, main linac, chicanes, and transfer lines. In this paper we provide an overview of the IMPACT code suite, its key capabilities, and recent enhancements pertinent to accelerator modeling for future linac-based light sources.
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| THPAS015 |
Three-Dimensional Integrated Green Functions for the Poisson Equation
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3546 |
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- D. T. Abell, P. J. Mullowney, K. Paul, V. H. Ranjbar
Tech-X, Boulder, Colorado
- J. Qiang, R. D. Ryne
LBNL, Berkeley, California
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Funding: Supported by US DOE Office of Science: Offices of Nuclear Physics, grant DE-FG02-03ER83796; High Energy Physics; and Advanced Scientific Computing Research, SciDAC Accelerator Science and Technology.
The standard implementation of using FFTs to solve the Poisson equation with open boundary conditions on a Cartesian grid loses accuracy when the change in G rho (the product of the Green function and the charge density) over a mesh cell becomes nonlinear; this is commonly encountered in high aspect ratio situations and results in poor efficiency due to the need for a very large number of grid points. A modification which solves this problem, the integrated Green function (IGF), has been implemented in two dimensions using linear basis functions and in three dimensions using constant basis functions. But, until recently, it has proved to be very difficult to implement IGF in three dimensions using linear basis functions. Recently significant progress has been made. We present both the implementation and test results for the three-dimensional extension.
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| FRPMS032 |
High-Order Modeling of an ERL for Electron Cooling in the RHIC Luminosity Upgrade using MaryLie/IMPACT
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4000 |
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- V. H. Ranjbar, D. T. Abell, K. Paul
Tech-X, Boulder, Colorado
- I. Ben-Zvi, J. Kewisch
BNL, Upton, Long Island, New York
- J. Qiang, R. D. Ryne
LBNL, Berkeley, California
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Funding: Work supported by the U. S. DOE Office of Science, Office of Nuclear Physics under grant DE-FG02-03ER83796.
Plans for the RHIC luminosity upgrade call for an electron cooling system that will place substantial demands on the energy, current, brightness, and beam quality of the electron beam. In particular, the requirements demand a new level of fidelity in beam dynamics simulations. New developments in MaryLie/IMPACT have improved the space-charge computations for beams with large aspect ratios and the beam dynamic computations for rf cavities. We present the results of beam dynamics simulations that include the effects of space charge and nonlinearities, and aim to assess the tolerance for errors and nonlinearities on current designs for a super-conducting ERL.
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| THPAS051 |
The RIAPMTQ/IMPACT Beam-Dynamics Simulation Package
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3606 |
| |
- T. P. Wangler, J. H. Billen, R. W. Garnett
LANL, Los Alamos, New Mexico
- V. N. Aseev, B. Mustapha, P. N. Ostroumov
ANL, Argonne, Illinois
- K. R. Crandall
TechSource, Santa Fe, New Mexico
- M. Doleans, D. Gorelov, X. Wu, R. C. York, Q. Zhao
NSCL, East Lansing, Michigan
- J. Qiang, R. D. Ryne
LBNL, Berkeley, California
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Funding: This work is supported by the U. S. Department of Energy, DOE contract number:W-7405-ENG-36
RIAPMTQ/IMPACT is a pair of linked beam-dynamics simulation codes that have been developed for end-to-end computer simulations of multiple-charge state heavy-ion linacs for future exotic-beam facilities. The simulations can extend from the low-energy beam transport after the ECR source to the end of the linac. The work has been performed by a collaboration including LANL, LBNL, ANL, MSU, and TechSource. The code RIAPMTQ simulates the linac front end including the LEBT, RFQ, and MEBT, and the code IMPACT simulates the main superconducting linac. The codes have been benchmarked for rms beam properties against previously existing codes at ANL and MSU. The codes allow high-statistics runs on parallel supercomputing platforms, such as NERSC at LBNL, as well as runs on desktop PC computers for low-statistics design work. We will show results from 10-million-particle simulations of RIA designs by ANL and MSU, carried out at the NERSC facility. These simulation codes will allow evaluations of candidate designs with respect to beam-dynamics performance including beam losses.
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