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Title |
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| TUOBAB01 |
Beam Dynamics of the 250 MeV Injector Test Facility
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785 |
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- A. Adelmann, R. J. Bakker, C. Kraus, K. L. Li, B. S.C. Oswald, M. Pedrozzi, J.-Y. Raguin, T. Schietinger, F. Stulle, A. F. Wrulich
PSI, Villigen
- J. Qiang
LBNL, Berkeley, California
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The PSI-FEL/LEG project aims for the development of a pulsed high-brightness, high-current electron source which is one of the cornerstones for a cost-efficient high-power laser-like X-ray light-source. Creating an ultra low emittance beam is a great challenge, transporting i.e. accelerating and compressing is equally difficult. We present a 3D start-to-end simulation of our planned 250 MeV injector test facility. The injector consists of a 2 cell standing wave l-band cavity followed by a ballistic bunching section. The following L-band and S-band structures accelerate the electron beam up to the final energy of 250 MeV. An X-band RF structure prepares the beam for the following bunch compressor in which the target current of 350 ampere is reached. The target value of the slice emittance is 0.10 [mm mrad] therefore precise beam dynamics simulations are needed. For the 3D simulations we use IMPACT-T, a time domain parallel particle tracking code in which the self fields are treated using electrostatic approximation . We discuss various issues such as projected and slice emittance preservation and shade light on some of the differences between an envelope and the 3D model.
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Slides
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| TUPMN116 |
Numerical Study of Coulomb Scattering Effects on Electron Beam from a Nano-tip
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1185 |
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- J. Qiang, J. N. Corlett, S. M. Lidia, H. A. Padmore, W. Wan, A. Zholents, M. S. Zolotorev
LBNL, Berkeley, California
- A. Adelmann
PSI, Villigen
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Funding: This work was supported by the U. S. Department of Energy under Contract no. DE-AC02-05CH11231.
Nano-tips with high acceleration gradient around the emission surface have been proposed to generate high brightness beams. However, due to the small size of the tip, the charge density near the tip is very high even for a small number of electrons. The Coulomb scattering near the tip can significantly degrade the beam quality and cause extra emittance growth and energy spread. In the paper, we present a numerical study of these effects using a direct relativistic N-body model. We found that emittance growth and energy spread, due to Coulomb scattering, can be significantly enhanced with respect to mean-field space-charge calculations in different parameter regimes.
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| THPAN076 |
Progress on H5Part: A Portable High Performance Parallel Data Interface for Electromagnetics Simulations
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3396 |
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- A. Adelmann, A. Gsell, B. S.C. Oswald, T. Schietinger
PSI, Villigen
- E. W. Bethel, J. M. Shalf, C. Siegerist, K. Stockinger
LBNL, Berkeley, California
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Significant problems facing all experimental and computational sciences arise from growing data size and complexity. Common to all these problems is the need to perform efficient data I/O on diverse computer architectures. In our scientific application, the largest parallel particle simulations generate vast quantities of six-dimensional data. Such a simulation run produces data for an aggregate data size up to several TB per run. Motived by the need to address data I/O and access challenges, we have implemented H5Part, an open source data I/O API that simplifies use of the Hierarchical Data Format v5 library (HDF5), which is an industry standard for high performance, cross-platform data storage and retrieval that runs on all contemporary architectures from large parallel supercomputers to laptops. H5part, which is oriented to the needs of the particle physics and cosmology communities, provides support for parallel storage and retrieval of particles, structured and in the future unstructured meshes. In this paper, we describe recent work focusing on I/O support for unstructure meshes and provide data showing performance on modern supercomputer architectures.
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