High precision modeling of space-charge effects is essential for designing future accelerators as well as optimizing the performance of existing machines. Synergia is a high-fidelity parallel beam dynamics simulation package with fully three dimensional space-charge capabilities and a higher-order optics implementation. We describe the Synergia framework and model benchmarks we obtained by comparing to semi-analytic results and other codes. We also present Synergia simulations of the Fermilab Booster accelerator and comparisons with experiment.

This book presents the most important and main concepts of the molecular and microsimulation techniques. It enables readers to improve their skills in developing simulation programs by providing physical problems and sample simulation programs for them to use. - Provides tools to develop skills in developing simulations programs - Includes sample simulation programs for the reader to use - Appendix explains Fortran and C languages in simple terms to allow the non-expert to use them

Computational methods for the modeling and simulation of the dynamic response and behavior of particles, materials and structural systems have had a profound influence on science, engineering and technology. Complex science and engineering applications dealing with complicated structural geometries and materials that would be very difficult to treat using analytical methods have been successfully simulated using computational tools. With the incorporation of quantum, molecular and biological mechanics into new models, these methods are poised to play an even bigger role in the future. Advances in Computational Dynamics of Particles, Materials and Structures not only presents emerging trends and cutting edge state-of-the-art tools in a contemporary setting, but also provides a unique blend of classical and new and innovative theoretical and computational aspects covering both particle dynamics, and flexible continuum structural dynamics applications. It provides a unified viewpoint and encompasses the classical Newtonian, Lagrangian, and Hamiltonian mechanics frameworks as well as new and alternative contemporary approaches and their equivalences in [start italics]vector and scalar formalisms[end italics] to address the various problems in engineering sciences and physics. Highlights and key features Provides practical applications, from a unified perspective, to both particle and continuum mechanics of flexible structures and materials Presents new and traditional developments, as well as alternate perspectives, for space and time discretization Describes a unified viewpoint under the umbrella of Algorithms by Design for the class of linear multi-step methods Includes fundamentals underlying the theoretical aspects and numerical developments, illustrative applications and practice exercises The completeness and breadth and depth of coverage makes Advances in Computational Dynamics of Particles, Materials and Structures a valuable textbook and reference for graduate students, researchers and engineers/scientists working in the field of computational mechanics; and in the general areas of computational sciences and engineering.

Cd-ROM contains: electronic version of AIP Conference Proceedings found in text.

The Fermilab Booster is a nearly 40-year-old proton synchrotron, designed to accelerate injected protons from a kinetic energy of 400 MeV to 8 GeV for extraction into the Main Injector and ultimately the Tevatron. Currently the Booster is operated with a typical intensity of 4.5 x 1012 particles per beam, roughly twice the value of its design, because of the requirement for high particle flux in various experiments. Its relatively low injection energy provides certain challenges in maintaining beam quality and stability under these increasing intensity demands. An understanding of the effects limiting this intensity could provide enhanced beam stability and reduced downtime due to particle losses and subsequent damage to the accelerator elements. Design of future accelerators can also benefit from a better understanding of intensity effects limiting injection dynamics. Chapter 1 provides a summary of accelerator research during the 20th century leading to the development of the modern synchrotron. Chapter 2 puts forth a working knowledge of the terminology and basic theory used in accelerator physics, and provides a brief description of the Fermilab Booster synchrotron. Synergia, a 3d space-charge modeling framework, is presented, along with some simulation benchmarks relevant to topics herein. Emittance, a commonly used quantity characterizing beam size and quality in a particular plane, is discussed in Chapter 3. Space-charge fields tend to couple the motion among the planes, leading to emittance exchange, and necessitating a simultaneous measurement to obtain a complete emittance description at higher intensities. A measurement is described and results are given. RMS beam emittances are shown to be in keeping with known Booster values at nominal intensities and emittance exchange is observed and accounted for. Unmeasurable correlation terms between the planes are quantified using Synergia, and shown to be at most an 8% effect. Results of studies on the coherent and incoherent shifts of transverse (betatron) frequencies with beam intensity at injection energies are presented. In Chapter 4 the coherent frequency shifts are shown to be due to dipole- and quadrupole-wakefield effects. The asymmetry of the Booster beam chamber through the magnets, as well as the presence of magnet laminations, are responsible for the magnitudes and for the opposing signs of the horizontal and vertical tune shifts caused by these wakefields. Chapter 5 details the procedures for obtaining a linear coherent-tune-shift intensity dependence, yielding -0.009/1012 in the vertical plane and +0.001/1012 in the horizontal plane. Data demonstrate a requirement of several hundred turns to accumulate to its maximal value. Two independent studies are compared, corroborating these results. In Chapter 6, a measure of the incoherent tune shift with intensity puts an upper limit on the magnitude of the direct space-charge effect in the Fermilab Booster. A prediction is made for the representative incoherent particle tune shift using a realistic Gaussian distribution, allowing for growth of the beam envelope with intensity, and found to be 0.004/1012. The tune-spread dependence obtained by quantification of the resonant stopband width from beam-extinction measurements was measured at 0.005/1012, similar to the predicted value. These will be shown to be one order of magnitude smaller than the space-charge term from the Laslett tune shift for a fixed-size, uniform beam.

This book provides a comprehensive treatment of intensity dependent particle beam instabilities in accelerating rings. Written for researchers, the material is also suitable for use as a textbook in an advanced graduate course for students studying accelerator physics. The presentation starts with a brief review of the basic concept of wake potentials and coupling impedances in the vacuum chamber followed by a discussion on static and dynamic solutions of their effects on the particle beams. Special emphasis is placed separately on proton and electron machines. Other special topics of interest covered include Landau damping, BalakinOCoNovokhatskyOCoSmirnov damping, Sacherer''s integral equations, Landau cavity, saw-tooth instability, Robinson stability criteria, beam loading, transition crossing, two-stream instabilities, and collective instability issues of isochronous rings. After the formulation of an instability, readers are provided a thorough description of one or more experimental observations together with a discussion of the cures for the instability. Although the book is theory oriented, the use of mathematics has been minimized. The presentation is intended to be rigorous and self-contained with nearly all the formulas and equations derived."

The Fermilab Booster is a nearly 40-year-old proton synchrotron, designed to accelerate injected protons from a kinetic energy of 400 MeV to 8 GeV for extraction into the Main Injector and ultimately the Tevatron. Currently the Booster is operated with a typical intensity of 4.5 x 10¹² particles per beam, roughly twice the value of its design, because of the requirement for high particle flux in various experiments. Its relatively low injection energy provides certain challenges in maintaining beam quality and stability under these increasing intensity demands. An understanding of the effects limiting this intensity could provide enhanced beam stability and reduced downtime due to particle losses and subsequent damage to the accelerator elements. Design of future accelerators can also benefit from a better understanding of intensity effects limiting injection dynamics. Chapter 1 provides a summary of accelerator research during the 20th century leading to the development of the modern synchrotron. Chapter 2 puts forth a working knowledge of the terminology and basic theory used in accelerator physics, and provides a brief description of the Fermilab Booster synchrotron. Synergia, a 3d space-charge modeling framework, is presented, along with some simulation benchmarks relevant to topics herein. Emittance, a commonly used quantity characterizing beam size and quality in a particular plane, is discussed in Chapter 3. Space-charge fields tend to couple the motion among the planes, leading to emittance exchange, and necessitating a simultaneous measurement to obtain a complete emittance description at higher intensities. A measurement is described and results are given. RMS beam emittances are shown to be in keeping with known Booster values at nominal intensities and emittance exchange is observed and accounted for. Unmeasurable correlation terms between the planes are quantified using Synergia, and shown to be at most an 8% effect. Results of studies on the coherent and incoherent shifts of transverse (betatron) frequencies with beam intensity at injection energies are presented. In Chapter 4 the coherent frequency shifts are shown to be due to dipole- and quadrupole-wakefield effects. The asymmetry of the Booster beam chamber through the magnets, as well as the presence of magnet laminations, are responsible for the magnitudes and for the opposing signs of the horizontal and vertical tune shifts caused by these wakefields. Chapter 5 details the procedures for obtaining a linear coherent-tune-shift intensity dependence, yielding -0.009/10¹² in the vertical plane and +0.001/10¹² in the horizontal plane. Data demonstrate a requirement of several hundred turns to accumulate to its maximal value. Two independent studies are compared, corroborating these results. In Chapter 6, a measure of the incoherent tune shift with intensity puts an upper limit on the magnitude of the direct space-charge effect in the Fermilab Booster. A prediction is made for the representative incoherent particle tune shift using a realistic Gaussian distribution, allowing for growth of the beam envelope with intensity, and found to be 0.004/10¹². The tune-spread dependence obtained by quantification of the resonant stopband width from beam-extinction measurements was measured at 0.005/10¹², similar to the predicted value. These will be shown to be one order of magnitude smaller than the space-charge term from the Laslett tune shift for a fixed-size, uniform beam.