MPPE  —  Single-Particle Beam Dynamics and Optics   (16-May-05   13:50—17:10)

Paper Title Page
MPPE002 Beam Propagation in Misaligned Magnetic Elements: A MatLab Based Code 826
 
  • T.F. Silva, M.L. Lopes, M.N. Martins, P.B. Rios
    USP/LAL, Bairro Butantan
 
  Funding: Fundacao de Amparo a Pesquisa do Estado de Sao Paulo - FAPESP Conselho Nacional de Desenvolvimento Cientifico e Tecnologico - CNPq.

We present a method to calculate kinematical parameters of a beam subject to a misaligned magnetic element. The procedure consists in transforming the kinematical parameters of the beam to the reference frame in which the magnetic element is aligned, propagating the beam through the element, and transforming back to the original frame. This is done using rotation matrices around the X-, Y-, and Z-axes. These matrices are not Lorentz invariant, so the rotations must be performed in a reference frame where the beam is at rest. We describe the transformation matrices, present a MatLab based code that uses this method to propagate up to 100 particles trough a misaligned quadrupole, and show some graphical outputs of the code.

 
MPPE003 Monte Carlo Simulations of Thin Internal Target Scattering In CELSIUS
 
  • Y.-N. Rao
    TRIUMF, Vancouver
  • D. Reistad
    TSL, Uppsala
 
  In the practical operation of the storage ring CELSIUS with the hydrogen pellet target, we simetimes observe a cooling phenomenon in the longitudinal phase space, that is, the circulating beam's phase space gets shrunk instead of blown up. This phenomenon occurs independently on the electron cooling. In this paper, we aim to investigate and interpret this phenomenon as well as the beam lifetime in the presence of hydrogen pellet target with and without rf and with and without electron cooling in CELSIUS using Monte Carlo simulations.  
MPPE004 Evaluation of Nonlinear Effects in the 3GeV Rapid Cycling Synchrotron of J-PARC 916
 
  • H. Hotchi, F. Noda, N. Tani
    JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • J. Kishiro, S. Machida, A.Y. Molodojentsev
    KEK, Ibaraki
 
  In order to accelerate an ultra-high intense beam with small particle losses, the 3GeV Rapid Cycling Synchrotron (RCS) of J-PARC, which is being constructed at JAERI, has a large acceptance. In this case the nonlinearity associated with the motion of particles at large amplitude and large momentum deviation plays a significant role. The sources of nonlinear magnetic fields in RCS are mainly connected with the fringe of the main dipole and quadrupole magnets and with the sextupole magnets used for the linear chromaticity correction. In this paper, we will present simulation results including such nonlinear effects. In addition, the possible correction scheme for the induced transverse resonances will be discussed.  
MPPE005 Dynamic Aperture and Resonance Correction for JPARC-RCS 979
 
  • A.Y. Molodojentsev, E. Forest, S. Machida
    KEK, Ibaraki
  • H. Hotchi, F. Noda, M.J. Shirakata, Y. Shobuda, H. Suzuki, K. Yamamoto
    JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • Y. Ishi
    Mitsubishi Electric Corp, Energy & Public Infrastructure Systems Center, Kobe
 
  Main intrinsic field nonlinearities, which are common for synchrotrons with large aperture, are the nonlinear field of the bending magnets, the fringing field of the magnets and the sextupole field nonlinearity, used for the chromaticity correction. The particle motion in the ring bending magnets has been analyzed by two methods: (1) by direct integration of the particle motion equations in the 3D magnetic field (Tosca output), based on the 4th order Runge-Kutta integrator and (2) by determination the transfer 8th order map of the bending magnet by using the Gaussian wavelet in the 3D space. The second technique allows us to use powerful tools such as the normal form analysis, to define the resonance driving terms, which can be used for the resonance correction. As the result of this study it was shown that the main limitation of the RCS dynamic aperture can be caused by the structure normal sextupole-order resonance and the normal octupole-order resonance. Other high-order resonances have smaller effects on the particles motion than the resonances mentioned above. The correction scheme to improve the dynamic aperture near the normal sextupole-order resonance has been analyzed.  
MPPE006 Particle Distribution Function Forming in Nonlinear Systems 985
 
  • S.N. Andrianov, S. Edamenko
    St. Petersburg State University, Applied Mathematics & Control Processes Faculty, St. Petersburg
 
  Modern ion-optical systems are used in different fields of beam physics both independent facilities as consisting of largemachines. One of these destination is to create beams with a desired distribution of beams particles. Often there is a need to ensure a homogeneous distribution for a terminal beam phase portrait in a transverse configuration space. This is one of problems of nonlinear aberrations management. It is known that nonlinearity properties inhere to any beam lines. Such these nonlinearities have unremovable character, and their influence can be remove using only special nonlinear lattice elements, which are introduced artificially into the beam line. In this paper we suggest a procedure to find necessary nonlinear correcting control elements for purposive forming of beam particle distribution functions.  
MPPE007 Problems of Conservative Integration in Beam Physics 1087
 
  • S.N. Andrianov, S. Abramova
    St. Petersburg State University, Applied Mathematics & Control Processes Faculty, St. Petersburg
 
  In this paper an approach to conservative integration methods development is discussed. This problem is very important for beam physics: from beam line synthesis up to long time evolution simulation. This approach is based on a Lie algebra technique. On the first step we find a special form of decomposition for a Lie map, describing the system under study. On the second step a researcher finds exact solutions for some classes of hamiltonians in symbolic forms. These steps allows forming an integration scheme, which have a desired symplectic property. The additional invariant and symmetry properties can be included using dynamical invariants conception.  
MPPE008 Synthesis of Beam Lines with Necessary Properties 1096
 
  • S.N. Andrianov
    St. Petersburg State University, Applied Mathematics & Control Processes Faculty, St. Petersburg
 
  In this paper a new approach to the problem of synthesis of beam lines is discussed. Usually this problem can be overcome by the use of numerical simulation and optimal control theory methods. But this results in sufficiently great number of variable parameters and functions. Obviously, that this degrades quality of a modeling procedure. The suggested approach is demonstrated on a problem of a microprobe design problem. Essence of the problem is that necessary to design a high precision focusing system which satisfies some additional conditions. For solution of this problem we use an algebraic treatment based on Lie algebraic methods and computer algebra techniques. Using the symmetry ideology this approach allows rewriting beam properties to enough simple conditions for control parameters and functions. This leads a set of desired solutions and show results in some most suitable form. Moreover, this approach decreases the number of variable parameters.  
MPPE009 2003-2004 Nonlinear Optics Measurements and Modeling for the CERN SPS 1171
 
  • A. Faus-Golfe
    IFIC, Valencia
  • G. Arduini, F. Zimmermann
    CERN, Geneva
  • R. Tomas
    CELLS, Bellaterra (Cerdanyola del Vallès)
 
  In 2003 and 2004 nonlinear chromaticity, amplitude detuning, chromatic phase advance, resonance driving terms and off-energy orbits were measured in the CERN SPS at 14 GeV/c and 26 GeV/c, respectively. From the nonlinear chromaticity, the SPS optics model has been updated, by adjusting the strength of nonlinear field errors in dipoles and quadrupoles. Furthermore, we have added to the model the effect of the displacement of all main bends and the voluntary misalignments of all the other elements of the machine. We compare the field errors with those founded in 2002, 2001 and 2000. The tune shifts with transverse amplitude, driving terms, etc., predicted by this nonlinear optics model are compared with direct measurements.  
MPPE011 Expected Emittance Growth and Beam Tail Repopulation from Errors at Injection into the LHC 1266
 
  • B. Goddard, H. Burkhardt, V. Kain, T. Risselada
    CERN, Geneva
 
  The preservation of the transverse emittance of the proton beam at injection into the LHC is crucial for luminosity performance. The population of the beam tails is also important for beam losses and collimation. The transfer and injection process is particularly critical in this respect, and several effects can contribute to the expected emittance increase and tail repopulation, like optical and geometrical mismatch, injection offsets and coupling, etc. The various effects are described, together with the tolerance limits on the parameters, and the expected contributions evaluated analytically where possible. The emittance growth and tail distributions are also simulated numerically using realistic errors. The implications for the tolerances on the matching of the transfer lines are discussed.  
MPPE012 MAD-X PTC Integration 1272
 
  • F. Schmidt
    CERN, Geneva
 
  MAD-X is CERN's successor for MAD8, a program for accelerator design with a long history. MAD-X is a modular, better maintainable re-write of MAD8 with data structures written in C. Early on in the design of MAD-X we relied on the fact that older or doubtful modules could be replaced by new modules using the PTC code by E. Forest. Both codes remain independent entities but are linked via a converter to the MAD-X data structures. PTC is used for symplectic tracking of smaller machines and transfer line using better defined physical models of the elements and taking into account of how the elements are placed in the tunnel. The matching of the LHC will profit form the fact that the high order nonlinear parameters are provided by a PTC Normal Form analysis.  
MPPE013 High Precision Measurement of Muon Beam Emittance Reduction in MICE 1330
 
  • C.T. Rogers, M. Ellis
    Imperial College of Science and Technology, Department of Physics, London
 
  Muon ionization cooling, an essential ingredient of a neutrino factory, will be demonstrated for the first time by the MICE experiment. The central part of MICE consists of a short section of a neutrino factory cooling channel and the emittance reduction achieved in this experiment is quite modest, 10% to 15%. In order to extrapolate the performance of a full cooling channel from these values, it is crucial for MICE to achieve an emittance measurement accuracy of 10-3 absolute. So far, beam emittance has never been measured with such a high level of precision and normailzed emittance in its present definition is not even conserved to 10-3 in the absence of dissipative forces. We present an improved definition of beam emittance and the requirements and constraints on MICE beam optics and spectrometers that are necessary to achieve the 10-3 level of accuracy.  
MPPE014 Non-Linear Beam Dynamics Studies of the Diamond Storage Ring 1410
 
  • R. Bartolini, A.I. Baldwin, M. Belgroune, I.P.S. Martin, J.H. Rowland, B. Singh
    Diamond, Oxfordshire
  • J.K. Jones
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
 
  The non-linear beam dynamics have been investigated for the non-zero dispersion lattice of the Diamond storage ring. Effects in realistic lattice configurations such as the introduction of coupling errors, beta beating, closed orbit correction, quadrupole fringe field and in-vacuum and helical insertion devices have been studied in the presence of realistic physical aperture limitations. Frequency map analysis together with 6D tracking allows identification of the limiting resonances as well as the loss locations and calculation of the influence of non-linear longitudinal motion on the Touschek lifetime. The sensitivity of the lattice to some of these effects leads to the identification of a better working point for the machine.  
MPPE015 Non-Linear Ring Model Calibration with Frequency Analysis of Betatron Oscillations 1452
 
  • R. Bartolini
    Diamond, Oxfordshire
  • F. Schmidt
    CERN, Geneva
 
  A precise model of an accelerator ring is crucial to achieve ultimate performance both in synchrotron light sources and high energy synchrotrons. Algorithms have been developed to calibrate the linear model of the ring. They have been successfully applied experimentally to determine and correct the linear optics of the machine. More recently the Frequency Map Analysis has been used to model also the non-linear optics. We propose here a technique based on the fit of non-linear spectral lines to recover the non-linear driving terms and to compensate the non-linear field errors around the ring.  
MPPE016 Hamiltonian Analysis of Transverse Dynamics in Axisymmetric RF Photoinjector 1476
 
  • C.-X. Wang
    ANL, Argonne, Illinois
 
  A general Hamiltonian that governs the beam dynamics in an rf photoinjector is derived from first principles. With proper choice of coordinates, the resulting Hamiltonian has a simple and familiar form, while taking into account the rapid acceleration, rf focusing, magnetic focusing, and space-charge forces. From the linear Hamiltonian, beam-envelope evolution is readily obtained, which better illuminates the theory of emittance compensation. Preliminary results on the third-order nonlinear Hamiltonian will be given as well.  
MPPE017 Longitudinal Acceptance in Linear Non-Scaling FFAGs 1532
 
  • J.S. Berg
    BNL, Upton, Long Island, New York
 
  Funding: Work supported by U.S. Department of Energy contract DE-AC02-98CH10886.

Linear Non-Scaling FFAGs have, particularly for muon acceleration, a unique type of longitudinal motion. This longitudinal motion can be approximated by a parabolic dependence time-of-flight on energy. This motion can be described in dimensionless variables with two parameters. I describe the relationship between the parameters and the distortion of ellipses in longitudinal space. I discuss the relationship between the longitudinal acceptance and the time spent in the FFAG, the latter being especially relevant for decays in muon accelerators. I discuss what improvement one can expect to achieve by adding higher-harmonic RF systems to the accelerator.

 
MPPE020 Control of Dynamic Aperture for Synchrotron Light Sources 1670
 
  • J. Bengtsson
    BNL, Upton, Long Island, New York
 
  Funding: Under Contract with the U.S. Department of Energy Contract Number DE-AC02-98CH10886.

Given the following frameworks: "A Hamiltonian-Free Description of Single Particle Dynamics for Hopelessly Complex Periodic Systems" (Forest, 1990), "Normal Form Methods for Complicated Periodic Systems" (Forest, Berz, Irwin, 1989), "The Correct Local Description for Tracking in Rings" (Forest, 1994), "The C++ Programming Language" (Stroustrup, 1985), we have designed a compact object oriented beam dynamics class by re-using existing FORTRAN libraries for: Truncated Power Series Algebra (Berz, SSC, 1988), and Map Normal Rorm (Forest, CBP, LBNL, 1990). In other words, implemented a numerical- and analytical model for: 6-dim phase space tracking, with classical radiation, and evaluation of equilibrium emittance, driving terms, amplitude dependent tune shifts, chromaticity, momentum compaction, etc., to arbitrary order, with self-consistent treatment of magnet errors. The tool was developed for the lattice design of NSLS-II.

 
MPPE021 Non-Linear Beam Transport System for the LENS 7 MeV Proton Beam 1704
 
  • W.P. Jones, D.V. Baxter, V.P. Derenchuk, T. Rinckel, K. A. Solberg
    IUCF, Bloomington, Indiana
 
  Funding: This work has been supported by the National Science Foundation under grants DMR-0220560 and DMR–0320627, by the Indiana 21st Century Science and Technology Fund, and by the Department of Defense.

A beam transport system has been designed to carry a high-intensity low-emittance proton beam from the exit of the RFQ-DTL acceleration system of the Indiana University Low Energy Neutron System (LENS)* to the neutron production target. The goal of the design was to provide a beam of uniform density over a 3cm by 3cm area at the target. Two octupole magnets** are employed in the beam line to provide the necessary beam phase space manipulations to achieve this goal. First order calculations were done using TRANSPORT and second order calculations have been performed using TURTLE. Second order simulations have been done using both a Gaussian beam distribution and a particle set generated by calculations of beam transport through the RFQ-DTL using PARMILA. Comparison of the design characteristics with initial measurements from the LENS commissioning process will be made.

*V.P. Derenchuk et al., "The LENS 7 MeV, 10mA proton Linac," these proceedings. **E. Kashy & B. Sherrill, Nuclear Instruments and Methods in Physics Research, B26 (1987) p. 610.

 
MPPE022 Modification to the Lattice of the Fermilab Debuncher Ring To Improve the Performance of the Stochastic Cooling Systems 1799
 
  • G. Dugan
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  • B. Ashmanskas
    Fermilab, Batavia, Illinois
 
  Funding: Supported by the Department of Energy and the National Science Foundation.

The Fermilab Debuncher is used to collect antiprotons from the production target, reduce the momentum spread of the beam by an RF bunch rotation, and stochastically cool the transverse and longitudinal emittances of the beam prior to transfer to the Accumulator. A large value of the slip factor of the ring lattice is favored to provide a larger momentum acceptance for the bunch rotation process, while a small value of the slip factor is desirable for stochastic cooling. A dynamic change in the lattice from a large slip factor at injection to a smaller slip factor at extraction would optimize both processes and could lead to an improvement in antiproton stacking rate. This paper discusses the details of lattice modifications to the Debuncher, achievable with the existing hardware, which would result in a 60% increase in the slip factor, while maintaining the tunes and chromaticities fixed, and keeping the betatron functions within an acceptable range.

 
MPPE023 Improvement of the Longitudinal Beam Dynamics Tuning Procedure for the MSU RIA Driver Linac 1826
 
  • M. Doleans
    MSU, East Lansing, Michigan
  • D. Gorelov, T.L. Grimm, F. Marti, X. Wu, R.C. York
    NSCL, East Lansing, Michigan
 
  The Rare Isotope Accelerator (RIA) driver linac will use a superconducting, cw linac with independently phased superconducting radio frequency cavities for acceleration and, for the heavier ions, utilize beams of multiple-charge-states (multi-q). Given the acceleration of multi-q beams and a stringent beam loss requirement in the RIA driver linac, a new beam envelope code capable of simulating nonlinearities of the multi-q beam envelopes in the longitudinal phase space was developed. Using optimization routines, the code is able to maximize the linearity of the longitudinal phase space motion and thereby minimizing beam loss by finding values for the amplitude and phase of the cavities for a given accelerating lattice. Relative motion of the multi-q beams is also taken into account so that superposition of the beam centroids and matching of their Twiss parameters are automatically controlled. As a result, the linac tuning procedure has been simplified and the longitudinal lattice performance has been improved. In this paper, the general architecture of the code and the results of using it to determine tuning parameters for the RIA driver linac are presented.  
MPPE024 Failure Modes Analysis for the MSU-RIA Driver Linac 1868
 
  • X. Wu, M. Doleans, D. Gorelov, T.L. Grimm, F. Marti, R.C. York
    NSCL, East Lansing, Michigan
 
  Previous end-to-end beam dynamics simulation studies* using experimentally-based input beams including alignment and rf errors and variation in charge-stripping foil thickness have indicated that the Rare Isotope Accelerator (RIA) driver linac proposed by MSU has adequate transverse and longitudinal acceptances to accelerate light and heavy ions to final energies of at least 400 MeV/u with beam powers of 100 to 400 kW. During linac operation, equipment loss due to, for example, cavity contamination, availability of cryogens, or failure of rf or power supply systems, will lead to at least a temporary loss of some of the cavities and focusing elements. To achieve high facility availability, each segment of the linac should be capable of adequate performance even with failed elements. Beam dynamics studies were performed to evaluate the linac performance under various scenarios of failed cavities and focusing elements with proper correction schemes, in order to prove the flexibility and robustness of the driver linac lattice design. The result of these beam dynamics studies will be presented.

*X. Wu, "End-to-End Beam Simulations for the MSU RIA Driver Linac," Proceedings of the XXII Linac Conference, Lubeck, Germany, August 2004.

 
MPPE025 Dynamical Effects Due to Fringe Field of the Magnets in Circular Accelerators 1907
 
  • Y. Cai, Y. Nosochkov
    SLAC, Menlo Park, California
 
  Funding: Work supported by the Department of Energy under Contract No. DE-AC02-76SF00515.

The leading Lie generators, including the chromatic effects, due to hard edge fringe field of single multipole and solenoid are derived from the vector potentials within a Halmitonian system. These nonlinear generators are applied to the interaction region of PEP-II to analyze the linear errors due to the feed-down from the off-centered quadrupoles and solenoid. The nonlinear effects of tune shifts at large amplitude, the synchro-betatron sidebands near half integer and their impacts on the dynamic aperture are studied in the paper.

 
MPPE027 Modeling of Non-linear Effects in RF Cavities
 
  • D.T. Abell, D.L. Bruhwiler
    Tech-X, Boulder, Colorado
  • I. Ben-Zvi
    BNL, Upton, Long Island, New York
 
  Funding: DOE: DE-FG02-03ER83796.

Emerging accelerator applications require beam radii comparable to RF cavity apertures, placing new demands on the modeling of particle motion in RF cavities using map-based techniques. A new method has been developed for computing nonlinear maps for arbitrary RF cavities.* We describe this new approach and present comparisons with more traditional approaches.

*D.T. Abell, in preparation.

 
MPPE028 Non Linear Error Analysis from Orbit Measurements in SPS and RHIC 2012
 
  • J.F. Cardona
    UNAL, Bogota D.C
  • R. Tomas
    BNL, Upton, Long Island, New York
 
  Funding: U.S. Department of Energy and Colciencias.

Recently, an "action and phase" analysis of SPS orbits measurements proved to be sensitive to sextupole components intentionally activated at specific locations in the ring. In this paper we attempt to determine the strenght of such sextupoles from the measured orbits and compare them with the set values. Action and phase analysis of orbit trayectories generated by RHIC models with non linearities will also be presented and compare with RHIC experiments.

 
MPPE030 Comparison of Off-Line IR Bump and Action-Angle Kick Minimization 2116
 
  • Y. Luo, F.C. Pilat, V. Ptitsyn, D. Trbojevic, J. Wei
    BNL, Upton, Long Island, New York
 
  Funding: Work supported by U.S. DOE under contract No. DE-AC02-98CH10886.

The interaction region bump (IR bump) nonlinear correction method has been used for the sextupole and octupole field error on-line corrections in the Relativistic Heavy Ion Collider (RHIC). Some differences were found for the sextupole and octupole corrector strengths between the on-line IR bump correction and the predictions from the action-angle kick minimization. In this report we compare the corrector strengths from these two methods based on the RHIC Blue ring lattice with the IR nonlinear modeling. The comparison confirms the differences between resulting corrector strengths. And the reason for the differences is found and discussed. It is followed by a further discussion of the operational IR bump applications to the octupole, and skew sextupole and skew quadrupole field error corrections.

 
MPPE031 Simulation of Resonance Streaming at the eRHIC Electron Storage Ring 2215
 
  • C. Montag
    BNL, Upton, Long Island, New York
 
  Funding: Work performed under the auspices of the U.S. Department of Energy.

To estimate electron beam lifetime and detector background at the future electron-ion collider eRHIC, knowledge of the electron beam halo region is essential. Simulations have been performed to determine the deviation of the transverse beam profile from a Gaussian distribution.

 
MPPE034 Symmetries and Invariants of the Time-dependent Oscillator Equation and the Envelope Equation 2315
 
  • H. Qin, R.C. Davidson
    PPPL, Princeton, New Jersey
 
  Funding: Research supported by the U.S. Department of Energy.

Single-particle dynamics in a time-dependent focusing field is examined. The existence of the Courant-Snyder invariant* is fundamentally the result of the corresponding symmetry admitted by the oscillator equation with time-dependent frequency.** A careful analysis of the admitted symmetries reveals a deeper connection between the nonlinear envelope equation and the oscillator equation. A general theorem regarding the symmetries and invariants of the envelope equation, which includes the existence of the Courant-Snyder invariant as a special case, is demonstrated. The symmetries of the envelope equation enable a fast algorithm for finding matched solutions without using the conventional iterative shooting method.

*E.D. Courant and H.S. Snyder, Ann. Phys. 3, 1 (1958). **R.C. Davidson and H. Qin, Physics of Intense Charged Particle Beams in High Energy Accelerators (World Scientific, 2001).

 
MPPE035 Transfers from High Power Hadron Linacs to Synchrotrons 2375
 
  • G.P. Jackson
    Hbar Technologies, LLC, West Chicago, Illinois
 
  The Fermilab Proton Driver is an example of a high power H- linear accelerator proposed as a new source of high brightness protons for the Main Injector synchrotron. Because of the elevated radioactive activation of accelerator components associated with beam losses during injection and acceleration, extra attention must be paid to RF manipulations wherein small losses were once deemed acceptable. Especially when injecting into existing synchrotrons from upgraded injectors, instabilities and beam loading make loss free manipulations especially problematic. This paper discusses some options for reducing the losses associated with common longitudinal beam manipulations.  
MPPE036 Characterization of the Chaotic or Regular Nature of Dynamical Orbits: A New, Fast Method 2449
 
  • I.V. Sideris
    Northern Illinois University, DeKalb, Illinois
 
  A new method of characterization of the regular or chaotic nature of dynamical orbits is introduced. It takes advantage of both morphological and dynamical properties of orbits, and can be applied to systems of all degrees of freedom. The new technique has been designed to analyze time-independent, time-dependent and N-body systems. It can provide straightforward information about the transition of orbits from regular to chaotic and vice versa, which can be found in time-dependent regimes. Equally important is the distinction it can make in time-independent regimes between sticky and wildly chaotic epochs during the evolution of chaotic orbits. Its most important advantage over the existing methods is, that it characterizes an orbit using information from a very small number of orbital periods. For these reasons the new method is extremely promising to be useful and effective in a broad spectrum of disciplines.  
MPPE038 Synchrotron Sidebands of a Linear Differential Coupling Resonance 2538
 
  • M. Takao, M. Masaki, J. Schimizu, K. Soutome, S. Takano, H. Tanaka
    JASRI/SPring-8, Hyogo
 
  Sidebands of a linear differential coupling resonance are observed in the tune survey of the SPring-8 storage ring. The vertical beam size and the Touschek beam lifetime blow up at a distance by synchrotron tune from the linear differential resonance. The synchrotron sidebands of a linear betatron coupling resonance are excited by the vertical dispersion at sextupole magnets. Although the vertical dispersion of the SPring-8 storage ring is well reduced to be small, order of 1 mm, the linear betatron coupling resonance is further suppressed. In addition, the sextupole magnets are relatively strong as well as other third generation light source facilities. Hence at the SPring-8 storage ring we can observe the synchrotron sidebands of the coupling resonance. By means of the tracking simulation based on the ring model obtained by the response matrix measurement we confirm the existence of the synchrotron sidebands of a linear differential coupling resonance. In order to incorporate synchrotron motion in the simulation, the 6-dimensional tracking code developed at SPring-8 is used.  
MPPE039 A C++ Framework for Conducting High-speed, Long-term Particle Tracking Simulations 2565
 
  • A.C. Kabel
    SLAC, Menlo Park, California
 
  High-resolution tracking studies such as the ones presented in*,** require unprecented amounts of CPU power. Usually, flexibility of a simulation code compromises performance; we have developed a C++ framework for parallel simulation of circular accelerators which provides a high degree of flexibility and programmability (parsing of MAD beamline descriptions, manipulation of beamlines and interfaces, optimization and matching of beamlines, tracking of particles or differential-algebraic objects) while achieving raw tracking speeds comparable to and surpassing hand-coded Fortran code. We describe some of the techniques used, such as compile-time polymorphism, meta-programming, and present benchmarking results.

*A. Kabel, Y. Cai, this conference. **A. Kabel, Y. Cai, T. Sen, V. Shiltsev, this conference.

 
MPPE040 Efficient Modeling of Nonlinear Beam Optics Using Parametric Model Independent Analysis
 
  • B. Sayyar-Rodsari, E. Hartman, C. Schweiger
    Pavilion Technologies, Inc, Austin, Texas
  • M.J. Lee, Y.T. Yan
    SLAC, Menlo Park, California
 
  Funding: Research supported by DOE grant number: DE-FG02-04ER86225.

Based on precision beam orbit measurements, Model Independent Analysis(MIA) has been used successfully to build a computer model that matches the linear optics of the real accelerator. We report a parametric extension of MIA that will allow efficient modeling of the nonlinear beam optics to account for energy dispersions. A simulation study is presented where the nonlinear dependency of lattice parameters on beam energy is captured by constrained training of a universal nonlinear approximator. These parametric nonlinear models of beam optics are easy to construct, diagnose, and modify. They can be very useful for more accurate model predicted beam operation and control.

 
MPPE041 Orbit Stability at the Brazilian Synchrotron Light Source 2687
 
  • L. Liu, P.F. Tavares
    LNLS, Campinas
 
  A task force has been implemented at the Brazilian Synchrotron Light Laboratory to improve the beam orbit stability in the 1.37 GeV electron storage ring. The main problems faced during this year (2004) were due to the installation of a second RF cavity in the machine. We describe the main problems and the solutions that were implemented.  
MPPE042 6-D BEAM DYNAMICS IN AN ISOCHRONOUS FFAG RING 2693
 
  • F. Meot
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  • F. Lemuet
    CERN, Geneva
  • G. Rees
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
 
  Funding: CEA/DAPNIA and CERN.

Numerical ray-tracing tools for 6-D tracking in FFAG accelerators have been developed. They are applied to the simulation of muon acceleration in the newly introduced isochronous type of FFAG ring designed for 16-turn, 8 to 20~GeV muon acceleration in the Neutrino Factory.

 
MPPE043 The Status of Optics Design and Beam Dynamics Study in J-PARC RCS 2759
 
  • F. Noda, N. Hayashi, H. Hotchi, J. Kishiro, P.K. Saha, Y. Shobuda, K. Yamamoto
    JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • S. Machida, A.Y. Molodojentsev
    KEK, Ibaraki
 
  The 3GeV RCS at J-PARC is designed to provide proton beam of 3GeV and a goal of output beam power is 1MW. The beam commissioning starts on May 2007. At present, more qualitative studies concerning beam dynamics are in progress: core beam handlings, halo beam handlings, instabilities and so on. In this paper, the RCS optics design and the present status of beam dynamics studies are summarized.  
MPPE044 Damping Wiggler Study at KEK-ATF 2809
 
  • T. Naito, H. Hayano, Y. Honda, K. Kubo, M. Kuriki, S. Kuroda, T. Muto, N. Terunuma, J.U. Urakawa
    KEK, Ibaraki
  • M. Korostelev, F. Zimmermann
    CERN, Geneva
  • N. Nakamura, H. Sakai
    ISSP/SRL, Chiba
  • M.C. Ross
    SLAC, Menlo Park, California
 
  The effects by damping wiggler magnets have been studied at KEK-ATF. The damping ring of the KEK-ATF is a 1.3 GeV storage ring capable of producing ultra-low emittance electron beams. It is significant issue to realize fast damping in the damping ring. The tuning method with 4 sets of wiggler was investigated for the ultra-low emittance beam. The performance on the beam quality, which is related to the transverse (x and y) and the longitudinal (z and dp/p), has been measured by the SR monitor, the laser wire, the streak camera and the energy spread monitor at the extraction line. We report on the operation condition and the measurement results.  
MPPE045 Accelerator Physics Issues at the 2.5 GeV PLS Storage Ring 2854
 
  • E.-S. Kim
    PAL, Pohang, Kyungbuk
 
  Over the past decade, PLS has served the synchrotron light source with the 2.0 GeV to 2.5 GeV electron beam. Accelerator physics issues at the present 2.5 GeV storage ring have been investigated in order to improve the performance of the light source. We present the issues of the low-beta lattice, low-emittance lattice, effects of six insertion devices on the lattice and low-alpha lattice, and show their effects on the beam dynamics in the storage ring.  
MPPE047 Optics Flexibility and Matching at LHC Injection 2983
 
  • H. Burkhardt, O.S. Brüning, B. Goddard, V. Kain, V. Mertens, T. Risselada, A. Verdier
    CERN, Geneva
 
  An excellent match between the SPS, the several kilometers long transfer lines and the LHC will be required to minimise emittance blow-up at injection. Several optics changes in the SPS and the LHC injection insertions had to be accommodated in the design phase. The new 3-phase collimation system in the transfer lines results in additional phase advance constraints. It will be important to maintain some tuning range for the LHC commissioning phase and to accommodate possible further optics changes. We analyse the requirements, the constraints, the current status and options to enhance the optics flexibility.  
MPPE048 Beam Based Alignment of the LHC Transfer Line Collimators 3034
 
  • V. Kain, H. Burkhardt, B. Goddard, S. Redaelli
    CERN, Geneva
 
  At LHC injection energy the aperture available in the transfer lines and in the LHC is small and the intensities of the injected beams are an order of magnitude above the damage level. The setting of protection elements such as the transfer line collimators is therefore very critical; mechanical and optical tolerances must be taken into account to define the nominal setting. Being able to measure and control the collinearity of the collimator jaws with the beam relaxes the requirement on the settings considerably. A method to measure angular misalignment of the collimator jaws in the transfer line based on a transmission measurement is discussed. Simulations have been made and are compared with the results of an alignment test performed with beam during the 2004 commissioning of the transfer line TI 8.  
MPPE049 Sensitivity Study for Evaluating the Extracted Beam Parameters of the LLUMC Proton Therapy Synchrotron 3046
 
  • G.H. Gillespie, W. Hill
    G.H. Gillespie Associates, Inc., Del Mar, California
  • G. Coutrakon, J. Hubbard, E. Sanders
    LLU/MC, Loma Linda, California
 
  The MINOS nonlinear constrained optimization program, working in concert with the beam optics code TRANSPORT, has been shown in recent work to provide a fast, efficient and reliable procedure for determining the parameters of the beam extracted from the LLUMC proton therapy synchrotron. MINOS and TRANSPORT work together as Modules of the Particle Beam Optics Laboratory (PBO Lab) software. The software was used to determine the parameters of the beam extracted from the synchrotron accelerator that best fit the extensive wire scanner profile data used to monitor the LLUMC proton therapy beamlines. In this paper additional constraints and optimizer variables are utilized with the procedure, in order to evaluate the sensitivity of the best fit extracted beam parameters to various assumptions. The methods used will be described and selected results from the study presented.  
MPPE051 Phase Trombone Program Migration for the Recycler at Fermilab 3135
 
  • M. Xiao
    Fermilab, Batavia, Illinois
 
  In the Recycler Ring, a phase trombone is used to control tunes. 9 pairs of independently power supplied adjustable quadruples are located in RR-60 straight section. They are segmented into 5 families currently to maintain a symmetrical structure. By adjusting these circuits, a tune variation of up to ±0.5 units is attainable. These adjustments are coordinated in such a way that the Twiss parameters at the ends of the straight section keep unchanged. A new phase trombone program is written in C and is integrated into the data acquisition program in CNS. This program now gets rid of network communication, and does not need to run code MAD. In this report, a test program written in Mathematic is described, and several matching conditions for the Twiss parameters are compared. Test results for the setting and measured tune values using running program on console are presented.  
MPPE052 Study on Coupling Issues in the Recycler at Fermilab 3209
 
  • M. Xiao, Y. Alexahin, D.E. Johnson, M.-J. Yang
    Fermilab, Batavia, Illinois
 
  We have been working and trying to answer the following questions: where are the coupling sources in the Recycler and is the existing correcting system working fine? In this paper, we report the analysis on the sources from both modeling by code MAD based on nonlinear lattice and real machine. From the first turn flesh orbit, we fit the off-plane orbits by third order polynomial, then separate 1st, 2nd and 3rd order coefficients to see different effects. On the other hand, we present the analysis from turn by turn data, which is to verify the phase of two skew quads families are more or less orthogonal, and to make sure the minimum tune split is small enough, and is consistent with the measurement.  
MPPE055 Fitting the Fully Coupled ORM for the Fermilab Booster 3322
 
  • X. Huang, S.-Y. Lee
    IUCF, Bloomington, Indiana
  • C.M. Ankenbrandt, E. Prebys
    Fermilab, Batavia, Illinois
 
  Funding: This work is supported in part by grants from DE-AC02-76CH03000, DOE DE-FG02-92ER40747 and NSF PHY-0244793.

The orbit response matrix (ORM) method* is applied to model the Fermilab Booster with parameters such as the BPM gains and rolls, and parameters in the lattice model, including the gradient errors and magnets rolls. We found that the gradients and rolls of the adjacent combined-function magnets were deeply correlated, preventing full determination of the model parameters. Suitable constraints of the parameters were introduced to guarantee an unique, equivalent solution. Simulations show that such solution preserves proper combinations of the adjacent parameters. The result shows that the gradient errors of combined-function magnets are within design limits.

*J. Safranek, Nucl. Instr and Meth. A, {\bf 388}, 27 (1997).

 
MPPE056 Studies to Increase the Anti-Proton Transmission from the Target to the Debuncher Ring 3357
 
  • I. Reichel, M.S. Zisman
    LBNL, Berkeley, California
  • K. Gollwitzer, S.J. Werkema
    Fermilab, Batavia, Illinois
 
  Funding: This work was supported by the Director, Office of Science, High Energy Physics, U.S. Department of Energy under Contracts No. DE-AC03-76SF00098 and DE-AC02-76CH03000.

The AP2 beamline at Fermilab transports anti-protons from the production target to the Debuncher ring. The measured admittance of the Debuncher ring and the theoretical aperture of the line are larger than the size of the transmitted beam. Extensive tracking studies were done using the Accelerator Toolbox (AT) to understand the sources of the difference. As simulations pointed to chromatic effects being a source of problems, measurements were done to study this. Several possible remedies were studied including adding sextupoles to the line to reduce the chromatic effects.

 
MPPE057 Measurement of the Vertical Emittance and Beta Function at the PEP-II Interaction Point Using the BaBar Detector 3387
 
  • J.M. Thompson, A. Roodman
    SLAC, Menlo Park, California
  • W. Kozanecki
    CEA/DSM/DAPNIA, Gif-sur-Yvette
 
  Funding: U.S. Department of Energy.

We present measurements of the effective vertical emittance and IP beta function in the PEP-II Asymmetric B Factory. These beam parameters are extracted from fits to the longitudinal dependence of the luminosity and of the vertical luminous size, measured using e+ e- –> mu+ mu- events recorded in the Babar detector. The results are compared, for different sets of machine conditions, to accelerator-based measurements of the optical functions of the two beams.

 
MPPE058 Virtual Accelerator for Accelerator Optics Improvement 3426
 
  • Y.T. Yan, Y. Cai, F.-J. Decker, S. Ecklund, J. Irwin, J. Seeman, M.K. Sullivan, J.L. Turner, U. Wienands
    SLAC, Menlo Park, California
 
  Funding: Work supported by Department of Energy contract DE-AC02-76SF00515.

Through determination of all quadrupole strengths and sextupole feed-downs by fitting quantities derivable from precision orbit measurement, one can establish a virtual accelerator that matches the real accelerator optics. These quantities (the phase advances, the Green's functions, and the coupling eigen-plane ellipses tilt angles and axis ratios) are obtained by analyzing turn-by-turn Beam Position Monitor (BPM) data with a model-independent analysis (MIA). Instead of trying to identify magnet errors, a limited number of quadrupoles are chosen for optimized strength adjustment to improve the virtual accelerator optics and then applied to the real accelerator accordingly. These processes have been successfully applied to PEP-II rings for beta beating fixes, phase and working tune adjustments, and linear coupling reduction to improve PEP-II luminosity.

 
MPPE059 Precision Measurement of Coupling Ellipses Parameters in a Storage Ring 3459
 
  • Y.T. Yan, Y. Cai
    SLAC, Menlo Park, California
 
  Funding: Work supported by Department of Energy contract DE-AC02-76SF00515.

Eigen-mode coupling ellipses' tilt angles and axis ratios can be precisely measured with a Model-Independent Analysis (MIA) of the turn-by-turn BPM data from resonance excitation of the betatron motion. For each BPM location one can measure 4 parameters from the two resonance excitation, which completely describe the linear coupling of the location. Results from application to PEP-II storage rings are presented.

 
MPPE060 Quadrupole Beam-Based Alignment at RHIC 3493
 
  • J. Niedziela, C. Montag, T. Satogata
    BNL, Upton, Long Island, New York
 
  Funding: Work performed under the auspices of the U.S. Department of Energy

Successful implementation of a beam-based alignment algorithm, tailored to different types of quadrupoles at RHIC, provides significant benefits to machine operations for heavy ions and polarized protons. This algorithm is used to calibrate BPM centers relative to interaction region (IR) quadrupoles to maximize aperture. It is also used to determine the optimal orbit through transition jump quadrupoles to minimize orbit changes during the transition jump for heavy ion acceleration. This paper provides background discussion and results from first application during the RHIC 2005 run.

 
MPPE061 Measurement and Correction of Nonlinear Chromaticity in RHIC 3523
 
  • S. Tepikian, P. Cameron, A. Della Penna, V. Ptitsyn
    BNL, Upton, Long Island, New York
 
  Funding: Work performed under Contract Number DE-AC02-98CH10886 with the auspices of the U.S. Department of Energy.

To improve luminosity in RHIC by using smaller Beta,* higher order chromatic effects may need to be corrected. Measuring of higher order chromaticities is discussed and compared to a model of RHIC, showing good agreement. Assuming round beams, four families of octupoles are used to correct the second order chromaticities while keeping under control the amplitude dependent betatron tune spread in the beams. We show that the octupoles can reduce the second order chromaticity in RHIC, but they have insufficient strength for complete correction.

 
MPPE062 Measurement and Optimization of Local Coupling from RHIC BPM Data 3553
 
  • R. Calaga, S. Abeytunge, M. Bai, W. Fischer
    BNL, Upton, Long Island, New York
  • F. Franchi
    GSI, Darmstadt
  • R. Tomas
    CELLS, Bellaterra (Cerdanyola del Vallès)
 
  Funding: U.S. Department of Energy.

Global coupling in RHIC is routinely corrected by using three skew quadrupole families to minimize the tune split. In this paper we aim to re-optimize the coupling at top energy by minimizing resonance driving terms and the C-matrix in two steps: 1. Find the best configuration of the three skew quadrupole families and 2. Identify locations with coupling sources by inspection of the driving terms and the C-matrix around the ring. The measurements of resonance terms and C-matrix are presented.

 
MPPE063 Optimization of Steering Elements in the RIA Driver Linac 3600
 
  • E.S. Lessner, V.S. Assev, P.N. Ostroumov
    ANL, Argonne, Illinois
 
  Funding: Work supported by the U.S. Department of Energy under contract W-31-109-ENG-38.

The driver linac of the projected RIA facility is a versatile accelerator, a 1.4-GV, CW superconducting linac designed to simultaneously accelerate several heavy-ion charge states, providing beams from protons at about 1 GeV to uranium at 400 MeV/u at power levels at a minimum of 100 kW and up to 400 kW for most beams. Acceleration of multiple-charge-state uranium beams places stringent requirements on the linac design. A steering algorithm was derived that fulfilled the driver’s real estate requirements, such as placement of steering dipole coils on SC solenoids and of beam position monitors outside cryostats, and beam-dynamics requirements, such as coupling effects induced by the focusing solenoids.* The algorithm has been fully integrated in the tracking code TRACK** and is used to study and optimize the number and position of steering elements that minimize the multiple-beam centroid oscillations and preserve the beam emittance under misalignments of accelerating and transverse focusing elements in the driver linac.

*E.S. Lessner and P.N. Ostroumov, Proceedings of the 9-th European Particle Accelerator Conference, July 2005, pp.1476-1478. **V.N. Aseev, P.N. Ostroumov, E.S. Lessner, and B. Mustapha, these proceedings.

 
MPPE064 Dynamic Aperture Study and Lifetime Improvement at the Advanced Photon Source 3632
 
  • V. Sajaev, L. Emery
    ANL, Argonne, Illinois
 
  Funding: Work supported by U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38.

Over past few years, the optics of the Advanced Photon Source storage ring was optimized to provide lower natural emittance. Presently, APS operates at 2.5 nm-rad emittance. The optimization was done at the expense of stronger sextupoles and shorter lifetime. Here we present our work on measurement and understanding the dynamic aperture of APS in low-emittance mode. We found good agreement between the dynamic aperture measurements and that of the model derived from the response matrix analysis. Based on the model, we were able to increase the lifetime significantly by optimizing sextupoles, correcting optics, moving working point, and adjusting rf voltage. The higher lifetime allowed us to decrease operating coupling from 2.5% to 1%.

 
MPPE065 Fully Coupled Analysis of Orbit Response Matrices at the FNAL Tevatron 3662
 
  • V. Sajaev
    ANL, Argonne, Illinois
  • V. Lebedev, V. Nagaslaev, A. Valishev
    Fermilab, Batavia, Illinois
 
  Funding: Work supported by U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38, and by the Universities Research Association, Inc., under contract DE-AC02-76CH03000 with the U.S. Dept. of Energy.

Optics measurements have played an important role in improving the performance of the FNAL Tevatron collider. Initial optics measurements were performed using a small number of differential orbits, which allowed us to carry out the first round of optics corrections. However, because of insufficient accuracy, it was decided to apply the response matrix analysis method for further optics improvements. The response matrix program developed at ANL has been expanded to include coupling – the essential feature required to describe the Tevatron optics. The results of the optics calibration are presented and compared to local beta function measurements.

 
MPPE066 Streak Camera Studies of Vertical Synchro-Betatron-Coupled Electron Beam Motion in the APS Storage Ring 3694
 
  • B.X. Yang, M. Borland, W. Guo, K.C. Harkay, V. Sajaev
    ANL, Argonne, Illinois
 
  Funding: Work supported by U.S. Department of Energy, Office of Basic Energy Sciences under Contract No. W-31-109-ENG-38.

We present experimental studies of synchro-betatron-coupled electron beam motion in the Advanced Photon Source storage ring. We used a vertical kicker to start the beam motion. When the vertical chromaticity is nonzero, electrons with different initial synchrotron phases have slightly different betatron frequencies from the synchronous particle, resulting in a dramatic progression of bunch-shape distortion. Depending on the chromaticity and the time following the kick, images ranging from a simple vertical tilt in the bunch to more complicated twists and bends are seen with a visible light streak camera. Turn-by-turn beam position monitor data were taken as well. We found that the experimental observations are well described by the synchro-betatron-coupled equations of motion. We are investigating the potential of using the tilted bunch to generate picosecond x-ray pulses. Also note that the fast increase in vertical beam size after the kick is dominated by the internal synchro-betatron-coupled motion of the electron bunch. Experimentally this increase could be easily confused with decoherence of vertical motion if the bunch is only imaged head-on.

 
MPPE067 Refined Calculation of Beam Dynamics During UMER Injection 3733
 
  • G. Bai, S. Bernal, T.F. Godlove, I. Haber, R.A. Kishek, P.G. O'Shea, B. Quinn, J.C. Tobin Thangaraj, M. Walter
    IREAP, College Park, Maryland
  • M. Reiser
    University Maryland, College Park, Maryland
 
  Funding: This work is funded by U.S. Dept. of Energy under grants DE-FG02-94ER40855 and DE-FG02-92ER54178.

The University of Maryland Electron Ring (UMER) is built as a low-cost testbed for intense beam physics for benefit of larger ion accelerators. The beam intensity is designed to be variable, spanning the entire range from low current operation to highly space-charge-dominated transport. The ring has recently been closed and multi-turn commissioning has begun. Although we have conducted many experiments at high space charge during UMER construction, lower-current beams have become quite useful in this commissioning stage for assisting us with beam steering, measurement of phase advance, etc. One of the biggest challenges of multi-turn operation of UMER is correctly operating the Y-shaped injection section, hence called the Y-section, which is specially designed for UMER multi-turn operation. It is a challenge because the system requires several quadrupoles and dipoles in a very stringent space, resulting in mechanical, electrical, and beam control complexities. This paper presents a simulation study of the beam centroid motion in the injection region.

 
MPPE068 Effects on Flat-Beam Generation from Space-Charge Force and Beamline Errors 3774
 
  • Y.-E. S. Sun
    University of Chicago, Chicago, Illinois
  • K.-J. Kim
    ANL, Argonne, Illinois
  • P. Piot
    Fermilab, Batavia, Illinois
 
  The transformation of a round, angular-momentum-dominated electron beam into a flat beam using a skew-quadrupole channel has been developed theoretically in several papers and demonstrated experimentally at the Fermilab/NICADD Photoinjector Laboratory. In this paper, we address the impacts of space-charge force and beamline errors on the round-to-flat beam transformation. We discuss the physical process of angular momentum cancellation during the beam passage through the skew-quadrupole channel, present analytical and numerical studies of the linear and nonlinear space-charge forces, and evaluate the corresponding limits on the ratio of vertical-to-horizontal emittances. We also investigate the sensitivities of flat-beam emittances on several systematic factors such as errors on quadrupole strengths and alignments.  
MPPE069 Optics for the ALBA Lattice 3777
 
  • M. Muñoz, D. Einfeld
    CELLS, Bellaterra (Cerdanyola del Vallès)
 
  ALBA will be a third generation synchrotron light source built in Spain near Barcelona. The lattice chosen for ALBA consists in an extended DBA-like structure with finite dispersion in the straight sections, providing low emittance (under 5nmrad), small beam cross sections at the source points (σ x ~ 150 micrometers and σ y ~ 10micrometers), and a large number of straight sections (4 times 8m, 12 times 4.2m and 8 times 2.6m). The small circumference (268 meters) and medium energy (3GeV) makes it challenging to provide the desired emittance while preserving a large enough dynamic aperture and energy acceptance. This paper reviews the main beam dynamics issues (dynamic aperture, energy acceptance, closed correction, lifetime, influence of insertion devices, and higher multipoles of magnets) and the solutions adopted.  
MPPE071 Einstein's General Relativity Effects on Beam Dynamics in a Storage Ring 3834
 
  • D. Dong, C.G. Huang, Z. Zusheng
    IHEP Beijing, Beijing
 
  Funding: The work is supported by National Science Foundation of China under Grant No. 10475094.

In this paper we will discuss Einstein's tide force predicted by Einstein's general relativity, how the new tide force would affect the beam orbits in a storage ring, and how to pick up and recognize it from the beam signals in a storage ring. The result shows this effect can be accumulated by the charged particle beam in a storage ring, it is a very interesting result.

 
MPPE073 Effects of the Passive Harmonic Cavity on the Beam Bunch 3904
 
  • L.-H. Chang, M.-C. Lin, C. Wang, M.-S. Yeh
    NSRRC, Hsinchu
 
  In this paper, we present a computer tracking code, which can investigate the bunch length, energy spread and the critical current of Robinson instability under the influence of the passive harmonic cavity. The effects of the radiation damping, quantum excitation and the beam loading of the harmonic cavity are included in the computation. The calculated result shows that the beam has a constant energy spread and blows up as the beam current increases from below to over the threshold current of the Robinson instability. It also indicates that the shunt impedance of the harmonic cavity is critical for whether the harmonic cavity can reach the designed goal, a stable and lengthening beam at the design beam current.  
MPPE074 Commissioning of a Locally Isochronous Lattice at ALS 3922
 
  • W. Wan, W.E. Byrne, H. Nishimura, G.J. Portmann, D. Robin, F. Sannibale, A. Zholents
    LBNL, Berkeley, California
 
  Funding: Work supported by the Director, Office of Energy Research, Office of Basic Energy Science, Material Sciences Division, U.S. Department of Energy, under Contract No. DE-AC03-76SF00098.

With the advance of ultrafast science, manipulating electron beam at the sub-micron and nanometer scale has been actively pursued. A special lattice of the ALS storage ring was conceived to studythe sub-micron longitudinal structure of the beam. It contains sections that are isochronous to the firstorder. Due to the practical constraints of the accelerator, sextupoles have to be off and the dispersion at the injection point is 60 cm, which make commissioning a highly nontrivial task. After a few months of tuning, we have been able to store at 30 mA of beam at the life time of 2 hours. After a brief introduction to the motivation of the experiment and the design of the lattice, the process and more detailed results of the commissioning will be presented. Future plan will also be discussed.

 
MPPE075 Simulation of the Effect of an In-Vacuum Undulator on the Beam Dynamics of the ALS 3949
 
  • W. Wan, C. Steier
    LBNL, Berkeley, California
 
  Funding: Work supported by the Director, Office of Energy Research, Office of Basic Energy Science, Material Sciences Division, U.S. Department of Energy, under Contract No. DE-AC03-76SF00098.

The femtosecond slicing project at the Advanced Light Source (ALS) requires that a short period (3 cm) and narrow gap (5.5 mm) in vacuum undulator to be installed. The combination of the short period and the narrow gap raised concern of the impact on the beam dynamics. A 3D field model was established based on numerical data using 8 longitudinal and 4 transverse harmonics. At first fourth-order symplectic integrator was used. It was to our surprise that the dynamic aperture decreased by a fact of 3. To understand the cause of the drastic change in the dynamic aperture, the field model was implemented in a differential algebraic code and the Taylor map of the undulator was obtained. Tracking result using the Taylor map showed little change in the dynamic aperture, which was latter corroborated by that using the symplectic integrator with 150 slices per period (as opposed to 10 before). Yet it is simply too time consuming to use the symplectic integrator with such thin slices. For this case, Taylor proves to be a much faster alternative.

 
MPPE076 Design Study on a New Separator for PEEM3 3985
 
  • W. Wan, J. Feng, H.A. Padmore
    LBNL, Berkeley, California
 
  Funding: Work supported by the Director, Office of Energy Research, Office of Basic Energy Science, Material Sciences Division, U.S. Department of Energy, under Contract No. DE-AC03-76SF00098.

A new aberration-corrected Photoemission Electron Microscope, called PEEM3, is under development at the Advanced Light Source. The resolution and transmission improvement is realized by correcting the lowest order spherical and chromatic aberrations using an electron mirror. A separator is required to separate the incoming uncorrected electron beam to the mirror from the corrected outgoing electron beam to the projector column. In this paper, we present a design study of a new separator for PEEM3. The layout, the Gaussian optics, the analysis of aberrations and the tolerance on power supply stability and alignment errors are reported.

 
MPPE080 Transversal Deflection of Electrons Moving in Parallel with Linearly Polarized Laser Beam and its Application 4054
 
  • D.A. Zakaryan, D.K. Kalantaryan
    YSU, Yerevan
  • E.D. Gazazyan, K.A. Ispirian, M.K. Ispirian
    YerPhI, Yerevan
 
  The motion of electrons in linearly polarized laser beams in a finite length interaction region and after in a field free drift length is investigated. It is shown that in the interaction region the trajectory of the electrons is almost straight lines with very small oscillation weakly depending on the laser intensity. In the drift region the electrons acquire significant transversal deflection that allows to carry out the measurement of the length and longitudinal particle distribution of femtosecond bunches. The dependence of this deflection upon the electron energy, interaction region length, etc is studied. The principles of the construction of femtosecond oscilloscopes are discussed.  
MPPE081 The Comparison of a New Beam-Tracking Code to the Acceleration Test 4072
 
  • K. Yamamoto, S. Yamada, K. Yamamoto
    NIRS, Chiba-shi
  • T. Hattori
    RLNR, Tokyo
  • M. Okamura
    RIKEN, Saitama
 
  A new beam-tracking code using a 3D electro-magnetic field map of a linac is being developed. In this code, beam dynamics including non-linear and dipole effects can be easily estimated based on simulated field maps provided by commercial 3D analysis software. To verify the code, we manufactured an IH-linac and acceleration test of the linac was carried out with proton beam. The simulated results were compared with the tested acceleration performances.  
MPPE082 Non-Linear Beam Dynamics in High Resolution Multi-Pass Time of Flight Mass Separator 4105
 
  • V.A. Shchepunov
    ORAU, Oak Ridge, Tennessee
  • H. Wollnik
    JIHIR, Oak Ridge, Tennessee
 
  Funding: This work was supported by the UNIRIB collaboration and Oak Ridge Associated Universities.

A multi-pass time-of-flight (MTOF) mass separator is under development by the UNIRIB collaboration. The MTOF consists of two coaxial electrostatic mirrors, focusing lenses and auxiliary injection, extraction and separation elements. The injected ions having almost the same energy but different masses undergo hundreds or thousands of reflections between the mirrors. In the course of this periodic motion, the ions of different masses and hence velocities are spatially separated in longitudinal direction. The periodic motion in the MTOF has been investigated with a recently developed ray tracing program utilizing the canonical integration technique. Results of the performed numerical simulations are discussed. The simulations displayed nonlinear character of the ion’s behavior both in transverse and longitudinal phase spaces. The ion’s transverse stability and longitudinal isochronicity were the matters of primary attention. It is shown in particular that at transverse tunes of around q=0.75 the system can be adjusted to be isochronous up to at least the 3rd order of the ToF optical aberrations.

 
MPPE083 Harmonic Decomposition of Orbit Data for Multipole Analysis 4120
 
  • M.-J. Yang
    Fermilab, Batavia, Illinois
 
  The unprecedented position resolution provided by the newly commissioned Recycer BPM system is opening up a new chapter of beam based multipole analysis at Fermilab. The closed orbit data, taken with circulating beam and averaged over many consecutive turns, has been shown to have the resolution of a few microns. The result of polynomial fit to BPM position data, as a function of dipole kick sizes, is used to separate orbit data into first, second, and third order. Combining both the in-plane and cross-plane orbit data it is possible to determine the multipole content within each half cell. This paper presents the algorithm behind the procedure, the data collected from the Fermilab Recycler Ring, and the final analysis result.  
MPPE084 Multipole error Analysis Using Local 3-Bump Orbit Data in Fermilab Recycler 4144
 
  • M.-J. Yang, M. Xiao
    Fermilab, Batavia, Illinois
 
  The magnetic harmonic errors of the Fermilab Recycler ring were examined using circulating beam data taken with closed local orbit bumps. Data was first parsed into harmonic orbits of first, second, and third order. Each of which was analyzed for sources of magnetic errors of corresponding order. This study was made possible only with the incredible resolution of a new BPM system that was commissioned after June of 2003.