Modern scientific datasets present numerous data management and analysis challenges. State-of-the-art index and query technologies are critical for facilitating interactive exploration of large datasets, but numerous challenges remain in terms of designing a system for processing general scientific datasets. The system needs to be able to run on distributed multi-core platforms, efficiently utilize underlying I/O infrastructure, and scale to massive datasets.

Particle accelerators are among the most complex and versatile instruments of scientific exploration. They have enabled remarkable scientific discoveries and important technological advances that span all programs within the DOE Office of Science (DOE/SC). The importance of accelerators to the DOE/SC mission is evident from an examination of the DOE document, "Facilities for the Future of Science: A Twenty-Year Outlook." Of the 28 facilities listed, 13 involve accelerators. In this talk I will discuss the tools and techniques of accelerator modeling from the historical perspective of my own career. First I will discuss several key developments relevant to 20th century accelerator simulation, including transfer map methods, Lie methods, and symplectic integration techniques. Next I will focus on 21st century accelerator modeling and the methods for large-scale accelerator simulation on parallel computers. Lastly I will describe the new generation of accelerator codes developed under SciDAC and future opportunities in the petascale era.

In this paper we present a self-consistent simulation model of colliding beams in high energy accelerators. The model, which is based on a particle-in-cell method, uses a new developed shifted-Green function algorithm for the efficient calculation of the beam-beam interaction. The model uses transfer maps to treat the external focusing elements and a stochastic map to treat radiation damping and quantum excitation of the beams. In the parallel implementation we studied various strategies to deal with the particular nature of the colliding beam system - a system in which there can be significant particle movement between beam-beam collisions. We chose a particle-field decomposition approach instead of the conventional domain decomposition or particle decomposition approach. The particle-field approach leads to good load balance, reduced communication cost, and shows the best scalability on an IBM SP3 among the three parallel implementations we studied. A performance test of the beam-beam model on a Cray T3E, IBM SP3, and a PC cluster is presented. As an application, we studied the effect of long-range collisions on antiproton lifetime in the Fermilab Tevatron.

This paper presents two new hardware-assisted rendering techniques developed for interactive visualization of the terascale data generated from numerical modeling of next-generation accelerator designs. The first technique, based on a hybrid rendering approach, makes possible interactive exploration of large-scale particle data from particle beam dynamics modeling. The second technique, based on a compact texture-enhanced representation, exploits the advanced features of commodity graphics cards to achieve perceptually effective visualization of the very dense and complex electromagnetic fields produced from the modeling of reflection and transmission properties of open structures in an accelerator design. Because of the collaborative nature of the overall accelerator modeling project, the visualization technology developed is for both desktop and remote visualization settings. We have tested the techniques using both time-varying particle data sets containing up to one billion particles per time step and electromagnetic field data sets with millions of mesh elements.

In many plasma physics and changed-particle beam dynamics problems, Coulomb collisions are modeled by a Fokker-Planck equation. In order to incorporate these collisions, we present a three-dimensional parallel Langevin simulation method using a Particle-In-Cell (PIC) approach implemented on high-performance parallel computers. We perform, for the first time, a fully self-consistent simulation, in which the friction and diffusion coefficients are computed from first principles. We employ a two-dimensional domain decomposition approach within a message passing programming paradigm along with dynamic load balancing. Object oriented programming is used to encapsulate details of the communication syntax as well as to enhance reusability and extensibility. Performance tests on the SGI Origin 2000, IBM SP RS/6000 and the Cray T3E-900 have demonstrated good scalability. As a test example, we demonstrate the collisional relaxation to a final thermal equilibrium of a beam with an initially anisotropic velocity distribution.

Article An object-oriented parallel particle-in-cell code for beam dynamics simulation in linear accelerators Share on Authors: J. Qiang LANL, Los Alamos, NM LANL, Los Alamos, NMView Profile , R. D. Ryne LANL, Los Alamos, NM LANL, Los Alamos, NMView Profile , S. Habib LANL, Los Alamos, NM LANL, Los Alamos, NMView Profile , V. Decyk UCLA, Los Angeles, CA UCLA, Los Angeles, CAView Profile Authors Info & Claims SC '99: Proceedings of the 1999 ACM/IEEE conference on SupercomputingJanuary 1999 Pages 55–eshttps://doi.org/10.1145/331532.331587Online:01 January 1999Publication History 4citation551DownloadsMetricsTotal Citations4Total Downloads551Last 12 Months3Last 6 weeks0 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access