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Paper Title Other Keywords Page
MOPA003 Testing of the LHC Magnets in Cryogenic Conditions: Operation Challenges, Status, and Outlook dipole, cryogenics, superconducting-magnet, collider 250
  • V. Chohan
    CERN, Geneva
  For the Large Hadron Collider under construction at CERN and the testing of its 1706 lattice magnets in cryogenic conditions, considerable challenges had to be overcome since 2002 to arrive at the situation of today, with semi-routine operation of the purpose built tests facility. With the setting up of an Operation Team comprising of non-expert CERN Accelerator operation staff, few in number and a large external collaboration, it was essential to develop the methodology of working in light of external collaboration limits and base it on CERN-known techniques and experience in accelerator running-in, commissioning and routine operation. A flavour of the operation tools that were necessary or developed will be given, i.e., web-based tests follow-up management & information systems, development of precisely defined ‘to do list’ of tests sequences, associated methods, procedures and strict check-lists, electronic logbooks and so forth. The presentation will briefly outline the test programme and its context & constraints, give a summary of the accomplishments so far, together with the outlook for the successful completion of the whole programme within the project goals.  
MOPA009 Global Decoupling on the RHIC Ramp coupling, betatron, injection, optics 659
  • Y. Luo, P. Cameron, A. Della Penna, W. Fischer, J.S. Laster, A. Marusic, F.C. Pilat, T. Roser, D. Trbojevic
    BNL, Upton, Long Island, New York
  Funding: Work supported by U.S. DOE under contract No. DE-AC02-98CH10886.

The global betatron decoupling on the ramp is an important issue for the operation of the Relativistic Heavy Ion Collider (RHIC). In the polarized proton run, the betatron tunes are required to keep almost constant on the ramp to avoid spin resonance line crossing and the beam polarization loss. Some possible correction schemes on the ramp, like three-ramp correction, the coupling amplitude modulation and the coupling phase modulaxtion, have been found. The principles of these schemes are shortly reviewed and compared. Operational results of their applications on the RHIC ramps are given.

MPPE002 Beam Propagation in Misaligned Magnetic Elements: A MatLab Based Code simulation, electron 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.

MPPE005 Dynamic Aperture and Resonance Correction for JPARC-RCS resonance, sextupole, injection, dynamic-aperture 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 octupole, focusing, target, lattice 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.  
MPPE008 Synthesis of Beam Lines with Necessary Properties focusing, target, simulation, octupole 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 optics, dipole, simulation, multipole 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.  
MPPE021 Non-Linear Beam Transport System for the LENS 7 MeV Proton Beam octupole, target, proton, beam-transport 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 lattice, sextupole, antiproton, injection 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.

MPPE025 Dynamical Effects Due to Fringe Field of the Magnets in Circular Accelerators resonance, dynamic-aperture, dipole, multipole 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.

MPPE039 A C++ Framework for Conducting High-speed, Long-term Particle Tracking Simulations lattice, insertion, multipole, factory 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 simulation, lattice, optics, beam-transport
  • 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 synchrotron, shielding, dipole, vacuum 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.  
MPPE047 Optics Flexibility and Matching at LHC Injection optics, injection, alignment, emittance 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.  
MPPE051 Phase Trombone Program Migration for the Recycler at Fermilab simulation, power-supply 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.  
MPPE055 Fitting the Fully Coupled ORM for the Fermilab Booster booster, lattice, focusing, simulation 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 lattice, sextupole, antiproton, simulation 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.

MPPE058 Virtual Accelerator for Accelerator Optics Improvement coupling, optics, lattice, luminosity 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.

MPPE060 Quadrupole Beam-Based Alignment at RHIC injection, alignment, optics, heavy-ion 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.

MPPE062 Measurement and Optimization of Local Coupling from RHIC BPM Data coupling, injection, dipole, betatron 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 linac, focusing, simulation, lattice 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.

MPPE065 Fully Coupled Analysis of Orbit Response Matrices at the FNAL Tevatron coupling, optics, storage-ring, luminosity 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.

MPPE067 Refined Calculation of Beam Dynamics During UMER Injection dipole, injection, simulation, electron 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 space-charge, emittance, gun, cathode 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.  
MPPE074 Commissioning of a Locally Isochronous Lattice at ALS lattice, sextupole, injection, coupling 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.

MPPE076 Design Study on a New Separator for PEEM3 electron, optics, focusing, dipole 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.

MPPE084 Multipole error Analysis Using Local 3-Bump Orbit Data in Fermilab Recycler coupling, multipole, dipole, closed-orbit 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.  
MPPP004 LHC Orbit Stablisation Tests at the SPS feedback, ground-motion, optics, collimation 886
  • R.J. Steinhagen, J. Andersson, L.K. Jensen, O.R. Jones, J. Wenninger
    CERN, Geneva
  The LHC presently build at CERN is the first proton collider that requires a continuous orbit control for safe and reliable machine operation. A realistic test of the orbit feedback system has been performed in 2004 using already present LHC instrumentation and infrastructure on a 270 GeV coasting beam in the SPS. It has been demonstrated that the chosen feedback architecture can stabilise the beam better than 10 micrometre and is essentially limited by the noise of the beam position monitor and the bandwidth of the corrector magnets. The achieved orbit stability is comparable to those found at modern light sources and gives enough operational margin with respect to the requirements of the LHC Cleaning System (70 micrometre). Estimates for the long term drifts and achievable stability will be presented based on the experimental results.  
MPPP013 Stabilizing Low Frequency Beam Motion in the Tevatron optics, damping, feedback, resonance 1353
  • V.H. Ranjbar
    Fermilab, Batavia, Illinois
  Funding: Operated by Universities Research Association Inc. under Contract No. DE-AC02-76CH03000 with the United States Department of Energy.

A feed back orbit stabilization system has been developed using a set of BPMS and existing Tevatron corrector magnets to stabilize beam motion up to 50 microns below 25 Hz. The construction of this system is described and the stability limits and magnitude of beam motion reduction is explored.

MPPT002 Design and Experiment of the BEPCII IR Conventional Dual Aperture Quadrupole multipole, septum, interaction-region, magnet-design
  • Z. Yin, Y. Wu, J.F. Zhang
    IHEP Beijing, Beijing
  The quadrupole magnet Q1a is one of the final horizontal focus quadrupoles for the Beijing Electron-Positron Collider Interaction Region (BEPCII IR). The BEPCII IR lattice design specification calls for a very high field quality for the quadrupole magnet. The Q1a is a conventional dual apertures quadrupole magnet. The required integral quadrupole strengths in two apertures are the same. This magnet is a septum quadrupole with high current density and solid core. 2D pole contour optimization and pole end chamfers are used to minimize harmonic error. The design methods, experiment results and magnet performances are described in this paper.  
MPPT004 End Chamfer Study and Field Measurements of the BEPCII Dipoles dipole, multipole, sextupole, factory 919
  • W. Chen, C. Cao, C. Shi, Z. Yin
    IHEP Beijing, Beijing
  The new BEPCII double ring will be added in the existing BEPC tunnel. There are more than 40 bending magnets named 67B in the new ring. The 67B is conventional ‘C’-type dipole magnet. The magnetic filed properties are dominated by the magnet end effect. The end effect have been studied and minimized by a proper end chamfer. Magnetic measurements of the prototype and productions were carried out using long coil. The developing process of the pole end chamfers and the measurement results of the 67B prototype and batch productions are described in the paper.  
MPPT009 HTS Power Leads for the BTeV Interaction Region interaction-region, magnet-design, power-supply, accumulation 1147
  • SF. Feher, R. H. Carcagno, D.F. Orris, Y.M.P. Pischalnikov, R. Rabehl, C. Sylvester, M. Tartaglia, J. Tompkins
    Fermilab, Batavia, Illinois
  Funding: DOE

A new Interaction Region for the BTEV experiment is planned to be built soon at Fermilab. This IR will require new superconducting quadrupole magnets and many additional power circuits for their operation. The new "low beta" quadupole magnet design is based upon the Fermilab LHC quadrupole design, and will operate at 9.56 kA in 4.5 K liquid helium. The use of conventional power leads for these circuits would require substantially more helium for cooling than is available from the cryogenic plant, which is already operating close to its limit. To decrease the heat load and helium cooling demands, the use of HTS power leads is necessary. Fermilab is in the process of procuring HTS leads for this new interaction region. Several 6 kA HTS leads produced by American Superconductor Corporation have been tested at over-current conditions. Based on the test results, design requirements are being developed for procuring the HTS current leads. This paper summarizes the test results and describes the design requirements for the 9.65 kA HTS power leads.

MPPT010 A New Correction Magnet Package for the Fermilab Booster Synchrotron sextupole, dipole, booster, multipole 1204
  • V.S. Kashikhin, D.J. Harding, J.A. John, J.R. Lackey, A. Makarov, W. Pellico, E. Prebys
    Fermilab, Batavia, Illinois
  Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-76CH03000.

Since its initial operation over 30 years ago, most correction magnets in the Fermilab Booster Synchrotron have only been able to fully correct the orbit, tunes, coupling, and chromaticity at injection (400MeV). We have designed a new correction package, including horizontal and vertical dipoles, normal and skew quadrupoles, and normal and skew sextupoles, to provide control up to the extraction energy (8GeV). In addition to tracking the 15Hz cycle of the main, combined function magnets, the quadrupoles and sextupoles must swing through their full range in 1ms during transition crossing. The magnet is made from 12 water-cooled racetrack coils and an iron core with 12 poles, dramatically reducing the effective magnet air gap and increasing the corrector efficiency. Magnetic field analyses of different combinations of multipoles are included.

MPPT013 New Pulsed Orbit Bump Magnets for the Fermilab Booster Synchrotron booster, injection, vacuum, linac 1341
  • J.R. Lackey, D.J. Harding, J.A. John, V.S. Kashikhin, A. Makarov, E. Prebys
    Fermilab, Batavia, Illinois
  Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-76CH03000.

The beam from the Fermilab Linac is injected onto a bump in the closed orbit of the Booster Synchrotron where a carbon foil strips the electrons from the Linac’s negative ion hydrogen beam. Although the Booster itself runs at 15Hz, heat dissipation in the orbit bump magnets has been one limitation to the fraction of the cycles that can be used for beam. New, 0.28T pulsed window frame dipole magnets have been constructed that will fit into the same space as the old ones, run at the full repetition rate of the Booster, and provide a larger bump to allow a cleaner injection orbit. The new magnets use a high saturation flux density Ni-Zn ferrite in the yoke rather than laminated steel. The presented magnetic design includes two and three dimensional magnetic field calculations with eddy currents and ferrite nonlinear effects.

MPPT016 Beam Injection for the PF-AR with a Single Pulsed Quadrupole Magnet injection, kicker, dipole, emittance 1517
  • K. Harada, Y. Kobayashi, T. Mitsuhashi, T. Miyajima, S. Nagahashi, T. Obina, A. Ueda
    KEK, Ibaraki
  We develop the injection system for PF-AR (Photon Factory Advanced Ring for Pulsed X-ray) with single pulse quadrupole (PQ) magnet without pulse local bump of the stored beam with four dipole kickers. The pulse quadrupole magnet has the length of 30cm, the field gradient of 3T/m, half-sine-form pulse width of 2.4mSec, measured inductance of 1.8mH and the peak current of about 2000A. With this magnet, the amplitude of the injected beam can be reduced to about the half of that only with septum magnets and the reduced amplitude is almost the same as the case of the usual injection with the pulse bump of the stored beam. We installed PQ-magnet at the short straight section near the south symmetric point of PF-AR in this summer of 2004 and succeeded to inject beam to the storage ring during the machine study in autumn, 2004.  
MPPT019 Magnet Design for the ISIS Second Target Station Proton Beam Line dipole, target, proton, septum 1652
  • C.M. Thomas, D.C. Faircloth, S.J.S. Jago
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  The ISIS facility, based at the Rutherford Appleton Laboratory in the UK, is an intense source of neutrons and muons for condensed matter research. The accelerator facility delivers an 800 MeV proton beam of 2.5x1013 protons per pulse at 50 Hz to the present target station. As part of a facility upgrade, it is planned to share the source with a second, 10 Hz, target station. The beam line supplying this target will extract from the existing target station beam line. Electromagnetic Finite Element Modelling techniques have been used to design the magnets required to meet the specified beam line optics. Kicker, septum, dipole, quadrupole, and steering magnets are covered. The magnet design process, involving 2D and 3D modelling, the calculation of ideal shims and chamfers, choice of steel, design of conducting coils, handling of heating issues and eddy current effects, is discussed.  
MPPT024 Rotating Coil Magnetic Measurement System and Measurement Results of Quadrupole Prototype for BEPCII Storage Ring multipole, pick-up, dipole, storage-ring 1844
  • L. Li, W. Chen, G. Ni, X.J. Sun
    IHEP Beijing, Beijing
  A normal quadrupole prototype magnet with 266-mm long, 105-mm aperture has been designed and fabricated by IHEP. Total of 88 quadrupole magnets are under fabrication. The multipole components, magnetic field gradient and transfer function of the quadrupole magnets were measured in September 2004, using an updated measurement system, which includes a rotating coil measurement system and a Hall probe measurement system. This paper mainly describes the updated harmonic coil magnetic field measurement system and provides the measurement results for BEPC II quadrupole magnets.  
MPPT025 Field Quality and Magnetic Center Stability Achieved in a Variable Permanent Magnet Quadrupole for the ILC permanent-magnet, multipole, alignment, linear-collider 1913
  • Y. Iwashita, T. Mihara
    Kyoto ICR, Uji, Kyoto
  • M. Kumada
    NIRS, Chiba-shi
  • C.M. Spencer
    SLAC, Menlo Park, California
  Funding: Work supported in part by Department of Energy contract DE–AC03–76SF00515 and by the Ministry of Education, Science, Sports and Culture, Japan, Grant-in-Aid for Scientific Research (A) 14204023.

The precise tolerances on the last two quadrupoles before the interaction point of the proposed, superconducting e+e- collider (ILC) have not been determined yet. These quads will be aligned with a beam-based alignment (BBA) process during which their integrated strengths will be decreased by 20%. Their magnetic centers must move by less than a few microns during the BBA else a systematic error will be introduced, yielding an increase in the beam spot size. These strong quads must be small to fit in the tight space. A compact, variable, superstrong permanent magnet quad (PMQ) has been fabricated and tested. The PMQ has inner and outer rings of NEOMAX; the outer ring is subdivided along its length and each section can rotate. By rotating different lengths one can vary the integrated strength in small steps. Because of the fixed inner ring and tight mechanical tolerances, the sensitivities of the magnetic center and pole angles to the rotation of the outer rings are largely suppressed. Measurements of the PMQ will be presented, plus how observed small center and angle shifts were further reduced by adjustments to the stopping angles of the rotating rings and by shimming these rings.

MPPT028 An Air Bearing Rotating Coil Magnetic Measurement System resonance, multipole, dipole, permanent-magnet 2038
  • S.C. Gottschalk, K.W. Kangas, D.J. Taylor, W.J. Thayer
    STI, Washington
  This paper describes a rotating coil magnetic measurement system supported on air bearings. The design is optimized for measurements of 0.1micron magnetic centerline changes on long, small aperture quadrupoles. Graphite impregnated epoxy resin is used for the coil holder and coil winding forms. Coil holder diameter is 11 mm with a length between supports of 750mm. A pair of coils is used to permit quadrupole bucking during centerline measurements. Coil length is 616mm, inner radius 1.82mm, outer radius 4.74mm. The key features of the mechanical system are simplicity; air bearings for accurate, repeatable measurements without needing warm up time and a vibration isolated stand that uses a steel-topped Newport optical table with air suspension. Coil rotation is achieved by a low noise servo motor controlled by a standalone Ethernet servo board running custom servo software. Coil calibration procedures that correct wire placement errors, tests for mechanical resonances, and other system checks will also be discussed.  
MPPT029 Performance of an Adjustable Strength Permanent Magnet Quadrupole permanent-magnet, linear-collider, collider, alignment 2071
  • S.C. Gottschalk, T.E. DeHart, K.W. Kangas
    STI, Washington
  • C.M. Spencer
    SLAC, Menlo Park, California
  • J.T. Volk
    Fermilab, Batavia, Illinois
  Funding: Department of Energy Grant DE-FG03-01ER83305.

An adjustable strength permanent magnet quadrupole suitable for use in Next Linear Collider has been built and tested. The pole length is 42cm, aperture diameter 13mm, peak pole tip strength 1.03Tesla and peak integrated gradient * length (GL) is 68.7 Tesla. This paper describes measurements of strength, magnetic centerline and field quality made using an air bearing rotating coil system. The magnetic centerline stability during -20% strength adjustment proposed for beam based alignment was < 0.2 microns. Strength hysteresis was negligible. Thermal expansion of quadrupole and measurement parts caused a repeatable and easily compensated change in the vertical magnetic centerline. Calibration procedures as well as centerline measurements made over a wider tuning range of 100% to 20% in strength useful for a wide range of applications will be described. The impact of eddy currents in the steel poles on the magnetic field during strength adjustments will be reported.

MPPT030 Magnetic and Engineering Analysis of an Adjustable Strength Permanent Magnet Quadrupole permanent-magnet 2122
  • S.C. Gottschalk, D.J. Taylor
    STI, Washington
  Funding: Department of Energy grant DE-FG03-01ER83305.

Magnetic and engineering analyses used in the design of an adjustable strength permanent magnet quadrupole will be reported. The quadrupole designed has a pole length of 42cm, aperture diameter 13mm, peak pole tip strength 1.03Tesla and peak integrated gradient * length (GL) of 68.7Tesla. Analyses of magnetic strength, field quality, magnetic centerline, temperature compensation and dynamic eddy currents induced during field adjustments will be presented. Magnet sorting strategies, pole positioning sensitivity, component forces, and other sensitivity analyses will be presented. Engineering analyses of stress, deflection and thermal effects as well as compensation strategies will also be shown.

MPPT031 Radiation Resistant Magnets for the RIA Fragment Separator radiation, target, dipole, sextupole 2200
  • A. Zeller, V. Blideanu, R.M. Ronningen, B. Sherrill
    NSCL, East Lansing, Michigan
  • R.C. Gupta
    BNL, Upton, Long Island, New York
  Funding: Supported in part by Michigan State University and the U.S. DOE.

The high radiation fields around the production target and the beam dump in the fragment separator at the Rare Isotope Accelerator requires that radiation resistant magnets be used. Because large apertures and high gradients are required for the quadrupoles and similar demanding requirements for the dipole and sextupoles, resistive coils are difficult to justify. The radiation heating of any materials at liquid helium temperatures also requires that superconducting versions of the magnets have low cold-masses. The final optical design has taken the practical magnets limits into account and sizes and fields adjusted to what is believed to be achievable with technology that is possible with sufficient R&D. Designs with higher obtainable current densities and having good radiation tolerances that use superconducting coils are presented, as well as the radiation transport calculations that drive the material parameters.

MPPT034 Field Modelling for the CESR-c Superconducting Wiggler Magnets wiggler, damping, emittance, linear-collider 2336
  • J.A. Crittenden, A.A. Mikhailichenko, A. Temnykh
    Cornell University, Department of Physics, Ithaca, New York
  • E.N. Smith, K.W. Smolenski
    Cornell University, Ithaca, New York
  Funding: National Science Foundation.

Superconducting wiggler magnets for operation of the CESR electron-storage ring at energies as low as 1.5 \gev have been designed, built and installed in the years 2000 to 2004. Finite-element models of field quality have been developed, various sources of field errors investigated and compared to field measurements. Minimization algorithms providing accurate analytic representations of the wiggler fields have been established. We present quantitative descriptions of field modelling, of measured field quality and of the accuracy achieved in the analytic functions of the field.

MPPT037 Design Study of Superconducting Magnets for the Super-KEKB Interaction Region superconducting-magnet, interaction-region, multipole, luminosity 2470
  • N. Ohuchi, Y. Funakoshi, H. Koiso, K. Oide, K. Tsuchiya
    KEK, Ibaraki
  The KEKB accelerator has achieved the highest luminosity of 1.39E1034cm-2s-1 at June-03-2004. For getting the higher luminosity over 1E1035cm-2s-1, the KEKB accelerator group continues to study the upgraded machine of the KEKB, that is the Super-KEKB. The designed machine parameters for this Super-KEKB are the vertical beta of 3 mm at the interaction point (IP), the LER and HER currents of 9.4 A and 4.1 A, and the half crossing angle of 15 mrad for the target luminosity of 1-5E1035cm-2s-1. For achieving these beam parameters, the superconducting magnets (final focus quadrupoles and compensation solenoids) are newly required to design. The magnet-cryostats have very tight spatial constraints against the Belle particle detector and the beam pipe so that the beam and the synchrotron light do not have any interference with the beam pipe. In this design, the final focus quadrupoles generate the field gradient of 42.3 T/m and their effective magnetic lengths are 0.30m and 0.36m in each side with respect to the IP, respectively. The compensation solenoids are overlaid with the quadrupoles. We will report the design of these magnets in detail and show the difficulties for the Super-KEKB-IR.  
MPPT042 Field Quality and Alignment of the Series Produced Superconducting Matching Quadrupoles for the LHC Insertions multipole, insertion, alignment, dipole 2738
  • N. Catalan-Lasheras, G. Kirby, R. Ostojic, J.C. Perez, H. Prin, W.  Venturini Delsolaro
    CERN, Geneva
  The production of the superconducting quadrupoles for the LHC insertions is advancing well and about half of the magnets have been produced. The coil size and field measurements performed on individual magnets both in warm and cold conditions are yielding significant results. In this paper we present the procedures and results of steering the series production at the magnet manufacturers and the assembly of cold masses at CERN. In particular, we present the analysis of warm-cold correlations and hysteresis of the main field multipoles, the correlation between coil sizes and geometrical field errors and the effect of permeability of magnet collars. The results are compared with the target errors for field multipoles and alignment.  
MPPT043 Low-Beta Quadrupole Designs for the LHC Luminosity Upgrade luminosity, insertion, dipole, multipole 2795
  • R. Ostojic, N. Catalan-Lasheras, G. Kirby
    CERN, Geneva
  Several candidate scenarios are considered for the upgrade of the LHC insertions in view of increasing the luminosity in excess of 1034 cm-2s-1. In all cases, superconducting low-beta quadrupoles with apertures in the range of 90-110 mm are required in view of increased heat loads and beam crossing angles. We present possible low-beta quadrupole designs based on Nb3Sn and NbTi superconducting cables, including existing LHC-class superconductors, present scaling laws for the magnet parameters and discuss relative advantages of the underlying triplet layouts.  
MPPT044 The Construction of the Low-Beta Triplets for the LHC multipole, insertion, vacuum, dipole 2798
  • R. Ostojic, M. Karppinen, T.M. Taylor, W.  Venturini Delsolaro
    CERN, Geneva
  • R. Bossert, J. DiMarco, SF. Feher, J.S. Kerby, M.J. Lamm, T.H. Nicol, A. Nobrega, T.M. Page, T. Peterson, R. Rabehl, P. Schlabach, J. Strait, C. Sylvester, M. Tartaglia, G. Velev
    Fermilab, Batavia, Illinois
  • N. Kimura, T. Nakamoto, T. Ogitsu, N. Ohuchi, t.s. Shintomi, K. Tsuchiya, A. Yamamoto
    KEK, Ibaraki
  The performance of the LHC depends critically on the low-beta triplets, located on either side of the four interaction points. Each triplet consists of four superconducting quadrupole magnets, which must operate reliably at up to 215 T/m, sustain extremely high heat loads and have an excellent field quality. A collaboration of CERN, Fermilab and KEK was set up in 1996 to design and build the triplet systems, and after nine years of joint effort the production will be completed in 2005. We retrace the main events of the project and present the design features and performance of the low-beta quadrupoles, built by KEK and Fermilab, as well as of other vital elements of the triplet. The experience in assembly of the first triplet at CERN and plans for tunnel installation and commissioning in the LHC are also presented. Apart from the excellent technical results, the construction of the LHC low-beta triplets has been a highly enriching experience combining harmoniously the different competences and approaches to engineering in a style reminiscent of physics experiment collaborations, and rarely before achieved in accelerator building.  
MPPT045 The Assembly of the LHC Short Straight Sections (SSS) at CERN: Project Status and Lessons Learned vacuum, collider, background, instrumentation 2890
  • V. Parma, N. Bourcey, P.M. Dos Santos de Campos, R.C. Feitor, mg. Gandel, R. Lopez, M. Schmidlkofer, I. Slits
    CERN, Geneva
  The series production of the LHC SSS has started in the beginning of 2004 and is foreseen to last until end 2006. The production consists in the assembly of 474 cold masses housing superconducting quadrupoles and corrector magnets within their cryostats. 87 cold mass variants, resulting from various combinations of main quadrupole and corrector magnets, have to be assembled in 55 cryostat types, depending on the specific cryogenic and electrical powering schemes required by the collider topology. The assembly activity features the execution of more than 5 km of leak-tight welding on 20-bar design pressure cryogenic lines in stainless steel and aluminium, according to high qualification standards and undergoing severe QA inspections. Some 2500 leak detection tests, using He mass spectrometry, are required to check the tightness of the cryogenic circuits. Extensive electrical control work, to check the integrity of the magnet instrumentation and electrical circuits throughout the assembly of the SSS, is also carried out. This paper presents the current status of production, the assembly facilities at CERN, work organisation and Quality Assurance issues, and the acquired assembly experience after one and a half years of production.  
MPPT048 Test Results of HTS Coil and Magnet R&D for RIA dipole, radiation, superconductivity, superconducting-magnet 3016
  • R.C. Gupta, M. Anerella, M. Harrison, W. Sampson, J. Schmalzle
    BNL, Upton, Long Island, New York
  • A. Zeller
    NSCL, East Lansing, Michigan
  Funding: Work supported by the U.S. Department of Energy and by the National Science Foundation.

Brookhaven National Laboratory is developing quadrupole magnets for the proposed Rare Isotope Accelerator (RIA) based on commercially available High Temperature Superconductors (HTS). These quadrupoles will be used in the Fragment Separator region and are one of the more challenging elements in the RIA proposal. They will be subjected to several orders of magnitude more energy and radiation deposition than typical beam line and accelerator magnets receive during their entire lifetime. The proposed quadrupoles will operate in the 20-40 K temperature range for efficient heat removal. HTS coils that have been tested so far indicate that the coils meet the magnetic field requirements of the design. We will report the test results of about 10 HTS coils and of a magnetic mirror configuration that simulates the magnetic field and Lorentz force in the proposed quadrupole. In addition, the preliminary design of an HTS dipole magnet for the Fragment Separator region will also be presented.

MPPT049 Optimization of Open Midplane Dipole Design for LHC IR Upgrade dipole, luminosity, optics, radiation 3055
  • R.C. Gupta, M. Anerella, A. Ghosh, M. Harrison, J. Schmalzle, P. Wanderer
    BNL, Upton, Long Island, New York
  • N.V. Mokhov
    Fermilab, Batavia, Illinois
  Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-98CH10886.

The proposed ten-fold increase in Large Hadron Collider (LHC) luminosity requires high field (~15 T) magnets that are subjected to the high radiation power of ~9 kW/per beam directed towards each interaction region. This has a major impact in the design of first dipole in the "Dipole First" optics. The proposed design allows sufficient clear space between coils so that most of the particle showers from the interaction points (concentrated at the midplane due to strong magnetic field) can be transported outside the coil region to a warm absorber thus drastically reducing the peak power density in the coils and removing heat at a higher (nitrogen) temperature. The concept, however, presents several new technical challenges: (a) obtaining good field quality despite a large midplane gap, (b) minimizing peak fields on coil, (c) dealing with large vertical forces with no structure between the coils, (d) minimizing heat deposition in the cold region, (e) designing a support structure. Designs with different horizontal and vertical coil spacing are presented that offer significant savings in the operating and infrastructure cost of the cryo-system, providing reliable quench-stable operation with a lifetime of the critical components of at least ten years.

MPPT050 Test Results for LHC Insertion Region Dipole Magnets dipole, sextupole, insertion, octupole 3106
  • J.F. Muratore, M. Anerella, J.P. Cozzolino, G. Ganetis, A. Ghosh, R.C. Gupta, M. Harrison, A.K. Jain, A. Marone, S.R. Plate, J. Schmalzle, R.A. Thomas, P. Wanderer, E. Willen, K.-C. Wu
    BNL, Upton, Long Island, New York
  Funding: U.S. Department of Energy.

The Superconducting Magnet Division at Brookhaven National Laboratory (BNL) has made 20 insertion region dipoles for the Large Hadron Collider (LHC) at CERN. These 9.45 m-long, 8 cm aperture magnets have the same coil design as the arc dipoles now operating in the Relativistic Heavy Ion Collider (RHIC) at BNL and are of single aperture, twin aperture, and double cold mass configurations. They produce fields up to 3.8 T for operation at 7.56 TeV. Eighteen of these magnets have been tested at 4.5 K using either forced flow supercritical helium or liquid helium. The testing was especially important for the twin aperture models, which have the most challenging design. In these, the dipole fields in both apertures point in the same direction, unlike LHC arc dipoles. This paper reports on the results of these tests, including spontaneous quench performance, verification of quench protection heater operation, and magnetic field quality. Magnetic field measurements were done at 4.5K and at room temperature, and warm-cold correlations have been determined. Some dynamic measurements to study the effect of time decay and snapback at injection were also done, using a fast rotating coil.

MPPT051 Reshimming of Tevatron Dipoles; A Process-Quality and Lessons-Learned Perspective dipole, controls, background, gun 3156
  • J.N. Blowers, R. Hanft, D.J. Harding, J.A. John, W.F. Robotham
    Fermilab, Batavia, Illinois
  Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-76CH03000.

Over the last two years corrections have been made for the skew quadrupole moment in 530 of the 774 installed dipoles in the Tevatron. This process of modifying the magnets in situ has inherent risk of degrading the performance of the superconducting accelerator. In order to manage the risk, as well as to ensure the corrections were done consistently, formal quality tools were used to plan and verify the work. The quality tools used to define the process and for quality control are discussed, along with highlights of lessons learned.

MPPT053 Restoring the Skew Quadrupole Moment in Tevatron Dipoles dipole, coupling, betatron 3244
  • D.J. Harding, P. Bauer, J.N. Blowers, J. DiMarco, H.D. Glass, R. Hanft, J.A. John, W.F. Robotham, M. Tartaglia, J. Tompkins, G. Velev
    Fermilab, Batavia, Illinois
  Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-76CH03000.

In early 2003 it was realized that mechanical changes in the Tevatron dipoles had led to a deterioration of the magnetic field quality that was hindering operation of the accelerator. After extensive study, a remediation program was started in late 2003 which will continue through 2005. The mechanical and magnetic effects are discussed. The readjustment process and experience are reported, along with other observations on aging magnets.

MPPT056 First Ideas Towards the Super-Conducting Magnet Design for the HESR at FAIR dipole, magnet-design, sextupole, antiproton 3354
  • R. Eichhorn, F.M. Esser, A. Gussen, S. Martin
    FZJ, Julich
  The Forschungszentrum Juelich has taken the leadership of a consortium being responsible for the design of the HESR going to be part of the FAIR project at GSI. The HESR is a 50 Tm storage ring for antiprotons, based on a super-conducting magnet technology. On basis of the RHIC Dipole D0 (3.6 T), the magnet design for the HESR has started recently. One key issue will be a very compact layout because of the rather short magnets (been 1.82 m for the dipoles and 0.5 m for the other magnets). This paper will present first ideas of the magnetic and cryogenic layout, give a status report on the achievements so far and discuss the need and possible solutions for a bent magnet with a radius of curvature of 13.2 m.  
MPPT061 Ideal Wiggler wiggler, emittance, focusing, dipole 3511
  • A.A. Mikhailichenko
    Cornell University, Department of Physics, Ithaca, New York
  Described is the wiggler with reduced nonlinear components for usage in damping ring of Linear Collider. Zigzag field dependence on longitudinal coordinate made by profiling of poles.  
MPPT064 Elements of Magneto-Optics Acting in One Direction octupole, wiggler, focusing, multipole 3618
  • A.A. Mikhailichenko
    Cornell University, Department of Physics, Ithaca, New York
  We describe here the way to use quadrupole, octupole lenses so they are acting in one direction only. The beam is running across the lens in contrast with usual axis running.  
MPPT068 A Compact High Gradient Pulsed Magnetic Quadrupole multipole, ion, heavy-ion, induction 3771
  • D. Shuman, A. Faltens, G. Ritchie, P.A. Seidl
    LBNL, Berkeley, California
  • M. Kireeff Covo
    LLNL, Livermore, California
  Funding: This work was supported by the Director, Office of Science, Office of Fusion Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC03-76SF00098.

A design for a high gradient, low inductance pulsed quadrupole magnet is presented. The magnet is a circular current dominated design with a circular iron return yoke. Features include a five turn eddy current compensated solid conductor coil design which theoretically eliminates the first four higher order multipole field components, a single layer "non-spiral bedstead" coil design which both minimizes utilization of radial space and maximizes utilization of axial space, and allows incorporation of steering and correction coils within existing radial space. The coils are wound and stretched straight in a special winder, then bent in simple fixtures to form the upturned ends, simplifying fabrication and assembly.

MPPT069 A Pulsed Solenoid for Intense Ion Beam Transport ion, heavy-ion, beam-transport, acceleration 3798
  • D. Shuman, E. Henestroza, G. Ritchie, D.L. Vanecek, W. Waldron, S. Yu
    LBNL, Berkeley, California
  Funding: This work was supported by the Director, Office of Science, Office of Fusion Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC03-76SF00098.

A design for a pulsed solenoid magnet is presented. Some simple design formulas are given that are useful for initial design scoping. Design features to simplify fabrication and improve reliability are presented. Fabrication, assembly, and test results are presented.

MPPT072 3D Simulation Studies of SNS Ring Doublet Magnets simulation, SNS, multipole, dipole 3865
  • J.-G. Wang
    ORNL, Oak Ridge, Tennessee
  • N. Tsoupas
    BNL, Upton, Long Island, New York
  • M. Venturini
    LBNL, Berkeley, California
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos, and Oak Ridge.

The accumulator ring of the Spallation Neutron Source (SNS) at ORNL employs in its straight sections closely packed quadrupole doublet magnets with large aperture of R=15.1 cm and relatively short iron-to-iron distance of 51.4 cm.* The magnetic interference among the magnets in the doublet assemblies is not avoidable due to the fringe fields. Though each magnet in the assemblies has been individually mapped to high accuracy of delta(B)/B~1x10-4, the experimental data including the magnet interference effect in the assemblies will not be available. We have performed 3D computer simulations on a quadrupole doublet model in order to assess the degree of the interference and to obtain relevant data which should be very useful for the SNS commissioning and operation. This paper reports our simulation results.

*N. Tsoupas et al. "A Large-aperture Narrow Quadrupole for the SNS Accumulator Ring," Proc. EPAC 2002, p.1106, Paris, June 3-7, 2002.

MPPT076 Conceptual Designs of Magnet Systems for the Taiwan Photon Source sextupole, storage-ring, dipole, vacuum 3979
  • C.-H. Chang, H.-H. Chen, T.-C. Fan, M.-H. Huang, C.-S. Hwang, J.C. Jan, W.P. Li, F.-Y. Lin, H.-C. Su
    NSRRC, Hsinchu
  The National Synchrotron Radiation Research Center (NSRRC) at Taiwan is designing a 3.0 GeV energy with ultra-low emittance storage ring for new Taiwan Photon Source (TPS) project. The storage has a circumference of 514 m with 24 periods of double-bend achromatic magnet system. The conceptual designs for each magnet family for the storage ring are optimize for operation of electron energy at 3.0- 3.3 GeV. This paper reviews the preliminary design and the key accelerator magnet issues.  
MPPT080 Design, Fabrication and Characterization of a Large-Aperture Quadrupole Magnet for CESR-c luminosity, photon, alignment, focusing 4063
  • M.A. Palmer, J.A. Crittenden, J. Kandaswamy, A. Temnykh
    Cornell University, Department of Physics, Ithaca, New York
  • T.I. O'Connell
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  Funding: National Science Foundation.

Installation of a radiative Bhabha luminosity monitor for CESR-c operation in 2004 required replacing a 40-mm aperture steel quadrupole magnet with one of aperture 75 mm, while maintaining field-quality tolerances at the level of a few parts in $104. We present the design methodology using 2D- and 3D-finite-element field calculations, compare the calculated 3D integrals to flip-coil measurements, and discuss related mechanical tolerances.

MPPT084 Dipole and Quadrupole Magnets for the Duke FEL Booster Injector dipole, booster, simulation, lattice 4147
  • S. Mikhailov
    DU/FEL, Durham, North Carolina
  • N. Gavrilov, D.G. Gurov, O.B. Kiselev, A.B. Ogurtsov, E.R. Rouvinsky, K.Zh. Zhiliaev
    BINP SB RAS, Novosibirsk
  Funding: This work is supported by U.S. DOE grant # DE-FG02-01ER41175 and by AFOSR MFEL grant # F49620-001-0370.

The full energy booster injector for the Duke FEL storage ring is presently under installation. The booster is designed to provide continuous injection into the Duke FEL storage ring in the top-off mode at the energy variable from 270 MeV to 1.2 GeV. The magnetic elements for the booster have been fabricated and magnetically measured in the Budker Institute of Nuclear Physics, Russia. The paper presents magnetic and mechanical design of the booster dipole and quadrupole magnets and results of their magnetic measurements. Results of simulation of the booster lattice taking into account residual field and non-linearity of the magnets are also presented.

MPPT086 Conventional Magnets Design for the Candle Storage Ring simulation, sextupole, storage-ring, dipole 4182
  • V.G. Khachatryan, A. Petrosyan
    CANDLE, Yerevan
  The lattice of 216m long CANDLE storage ring (16 Double Bend Achromat cells) will contain 32 gradient dipole magnets, 80 quadrupole magnets of three types and two types of 64 sextupole magnets. Magnetic as well as mechanical design of those magnets has been performed relying on extensive world experience. Computer simulations and large volume of computations have been carried out to design magnets that conform to strict requirements.  
TOAC004 Experimental Investigation of Beam Breakup in the Jefferson Laboratory 10 kW FEL Upgrade Driver damping, optics, simulation, recirculation 369
  • C. Tennant, D. Douglas, K. Jordan, L. Merminga, E.P. Pozdeyev, H. Wang
    Jefferson Lab, Newport News, Virginia
  • I.V. Bazarov
    Cornell University, Department of Physics, Ithaca, New York
  • G. Hoffstaetter
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  • S. Simrock
    DESY, Hamburg
  • T.I. Smith
    Stanford University, Stanford, Califormia
  Funding: This work supported by the Office of Naval Research, the Joint Technology Office, the Commonwealth of Virginia, the Air Force Research Laboratory, Cornell University and by DOE Contract DE-AC05-84ER40150.

In recirculating accelerators, and in particular energy recovery linacs (ERLs), the maximum current has been limited by multipass, multibunch beam breakup (BBU), which occurs when the electron beam interacts with the higher-order modes (HOMs) of an accelerating cavity on the accelerating pass and again on the energy recovered pass. This effect is of particular concern in the design of modern high average current energy recovery accelerators utilizing superconducting technology. Experimental observations of the instability at the Jefferson Laboratory 10 kW Free-Electron Laser (FEL) are presented. Measurements of the threshold current for the instability are presented and compared to the predictions of several BBU simulation codes. To further characterize the instability, beam based measurements were made to determine the orientation of the dangerous HOMs. With BBU posing a threat to high current beam operation in the FEL, several suppression schemes were developed. These include direct damping of the dangerous HOMs and appropriately modifying the electron beam optics. Preliminary results of their effectiveness in raising the threshold current for stability are presented.

TOAA002 U.S. Accelerator Contribution to the LHC alignment, dipole, luminosity, interaction-region 184
  • M.J. Lamm
    Fermilab, Batavia, Illinois
  In 1998, the United States entered into an agreement with CERN to help build the Large Hadron Collider (LHC), with contributions to the accelerator and to the large HEP detectors. To accomplish this, the US LHC Accelerator Project was formed, encompassing expertise from Brookhaven National Laboratory, Fermi National Accelerator Laboratory and the Lawrence Berkeley National Laboratory. Contributions from the US LHC Accelerator project included superconducting high gradient quadrupoles and beam separation dipoles for the four interaction regions and the RF section; feedboxes for cryogenic, power and instrumentation distribution; neutral and hadron beam absorbers in the high luminosity regions; design of the inner triplet cryogenic system; beam tracking studies utilizing the design IR magnet field quality and magnet alignment; particle heat deposition studies in the IR’s; and short sample characterization of superconducting cables used in the arc dipoles and quadrupoles. This report is a summary of these contributions including the progress towards project completion, as well as a discussion of future plans for US participation in the LHC accelerator.  
TOAA004 Field Quality Study in Nb3Sn Accelerator Magnets sextupole, dipole, alignment 366
  • V. Kashikhin, G. Ambrosio, N. Andreev, E. Barzi, R. Bossert, J. DiMarco, V.S. Kashikhin, M.J. Lamm, I. Novitski, P. Schlabach, G. Velev, R. Yamada, A.V. Zlobin
    Fermilab, Batavia, Illinois
  Funding: This work was supported by the U.S. Department of Energy.

High field accelerator magnets are being developed at Fermilab for present and next generation hadron colliders. These magnets are designed for a nominal field of 10-12 T in the magnet bore of 40-50 mm and an operating temperature of 4.5 K. To achieve these design parameters, a new, high-performance Nb3Sn superconducting strand is used. Four short Nb3Sn dipole models of the same design based on a single-bore cos-theta coil and a cold iron yoke have been fabricated and tested at Fermilab. Their field quality was measured at room temperature during magnet fabrication and at helium temperature. This paper reports the results of warm and cold magnetic measurements. The systematic geometrical harmonics and their RMS spread due to cross-section imperfections, the coil magnetization effects caused by persistent currents in superconductor and eddy current in the cable, the "snap-back" effect at injection and the iron saturation effect at high fields are presented and compared with theoretical predictions.

TOAA006 Development of Superconducting Combined Function Magnets for the Proton Transport Line for the J-PARC Neutrino Experiments dipole, proton, alignment, target 495
  • T. Nakamoto, Y. Ajima, Y. Fukui, N. Higashi, A. Ichikawa, N. Kimura, T. Kobayashi, Y. Makida, T. Ogitsu, H. Ohhata, T. Okamura, K. Sasaki, M. Takasaki, K. Tanaka, A. Terashima, T. Tomaru, A. Yamamoto
    KEK, Ibaraki
  • M. Anerella, J. Escallier, G. Ganetis, R.C. Gupta, M. Harrison, A.K. Jain, J.F. Muratore, B. Parker, P. Wanderer
    BNL, Upton, Long Island, New York
  • T. Fujii, E. Hashiguchi, T. Kanahara, T. Orikasa
    Toshiba, Yokohama
  • Y. Iwamoto
    JAERI, Ibaraki-ken
  • T. Obana
    GUAS/AS, Ibaraki
  A second generation of long-baseline neutrino oscillation experiments has been proposed as one of the main projects at J-PARC jointly built by JAERI and KEK. Superconducting combined function magnets, SCFMs, will be utilized for the 50 GeV, 750 kW proton beam line for the neutrino experiment and an R&D program is in underway at KEK. The magnet is designed to provide a combined function of a dipole field of 2.6 T with a quadrupole field of 19 T/m in a coil aperture of 173.4 mm. A series of 28 magnets in the beam line will be operated DC in supercritical helium cooling below 5 K. A design feature of the SCFM is the left-right asymmetry of the coil cross section: current distributions for superimposed dipole- and quadrupole- fields are combined in a single layer coil. Another design feature is the adoption of glass-fiber reinforced phenolic plastic spacers to replace the conventional metallic collars. To evaluate this unique design, fabrication of full-scale prototype magnets is in progress at KEK and the first prototype will be tested at cold soon. This paper will report the development of the SCFMs.  
TOAA008 Progress and Status in SNS Magnet Measurements at ORNL dipole, SNS, linac, permanent-magnet 609
  • T. Hunter, SH. Heimsoth, DL. Lebon, RM. McBrien, J.-G. Wang
    ORNL, Oak Ridge, Tennessee
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos, and Oak Ridge.

The Spallation Neutron Source (SNS) contains more than 600 magnets. Among them, about 400 magnets for the Linac and transfer lines are being measured on site at Oak Ridge National Laboratory. These magnets include Permanent Magnet Quadrupoles, Electro-magnetic Quadrupoles, Dipoles and Correctors. The Permanent Magnet Quadrupoles are installed in the Drift Tube Linac (DTL) and are the only Permanent Magnets in the machine. These measurements are for magnets installed in the DTL, Coupled Cavity Linac (CCL), Superconducting Linac (SCL), High Energy Beam Transport (HEBT), and the Ring to Target Beam Transport (RTBT) line. All magnets have met specifications. Approximately three fourths of the magnets have so far been measured and installed. This presentation outlines the magnet measurements for SNS at ORNL and overviews the activities and accomplishments to date.

TOAA010 Serpentine Coil Topology for BNL Direct Wind Superconducting Magnets dipole, octupole, superconducting-magnet, multipole 737
  • B. Parker, J. Escallier
    BNL, Upton, Long Island, New York
  Funding: Work supported by the U.S. Department of Energy under contract DE-AC-02-98-CH10886.

BNL direct wind technology, with the conductor pattern laid out without need for extra tooling (no collars, coil presses etc.) began with RHIC corrector production. RHIC patterns were wound flat and then wrapped on cylindrical support tubes. Later for the HERA-II IR magnets we improved conductor placement precision by winding directly on a support tube. To meet HERA-II space and field quality goals took sophisticated coil patterns, (some wound on tapered tubes). We denote such patterns, topologically equivalent to RHIC flat windings, "planar patterns." Multi-layer planar patterns run into trouble because it is hard to wind across existing turns and magnet leads get trapped at poles. So we invented a new "Serpentine" winding style, which goes around 360 degrees while the conductor winds back and forth on the tube. To avoid making solenoidal fields, we wind Serpentine layers in opposite handed pairs. With a Serpentine pattern each turn can have the same projection on the coil axis and integral field harmonics then closely follow the 2D cross section. This and other special Serpentine coils properties are discussed in this paper and applied to a variety of direct wind magnet projects.

TPAE012 Rectangular Diamond-Lined Accelerator Structure acceleration, impedance, vacuum, linear-collider 1282
  • C. Wang, V.P. Yakovlev
    Omega-P, Inc., New Haven, Connecticut
  • J.L. Hirshfield
    Yale University, Physics Department, New Haven, CT
  Funding: Work supported by U.S. DOE.

For high frequency accelerators with normal-conducting structures studied by the NLC/GLC collaboration and the CLIC group, rf breakdown is the main gradient limitation. In this paper, a Ka-band rectangular dielectric-lined structure is described as an attempt to increase accelerating gradient beyond the limits suitable for metallic structures. The structure is based on amorphous dielectrics that are known to exhibit high breakdown limits (~ GV/m). An example is artificial diamond that has already been successfully used on an industrial basis for large-diameter output windows of high power gyrotrons, and is produced industrially in increasing quantities. Artificial diamond has low loss tangent, moderate dielectric constant and high breakdown limit of ~2 GV/m. In the proposed structure diamond-slabs are employed to support high-gradient acceleration fields. Interposition of vacuum gaps between the dielectric slabs and the side walls is shown to reduce Ohmic losses substantially, leading to an increase in shunt impedance and reduced susceptibility to rf breakdown and fatigue on metal surfaces.

TPAE048 The UCLA/FNPL Time Resolved Underdense Plasma Lens Experiment plasma, electron, focusing, space-charge 3013
  • M.C. Thompson, H. Badakov, J.B. Rosenzweig, G. Travish
    UCLA, Los Angeles, California
  • H. Edwards, R.P. Fliller, G.M. Kazakevich, P. Piot, J.K. Santucci
    Fermilab, Batavia, Illinois
  • J.L. Li, R. Tikhoplav
    Rochester University, Rochester, New York
  Funding: Work Supported by U.S. Dept. of Energy grant DE-FG03-92ER40693.

An underdense plasma lens experiment is planned as a collaboration between UCLA and the Fermilab NICADD Photoinjector Laboratory (FNPL). The experiment will focus on measuring the variation of the plasma focusing along the longitudinal beam axis and comparing these results with theory and simulation. The experiment will utilize a thin gaussian underdense plasma lens with peak density 6 x 1012 cm-3 and a FWHM length of 1.6 cm. This plasma lens will have a focusing strength equivalent to a quadrupole magnet with a 180 T/m field gradient. A 15 MeV, 8nC electron beam with nominal dimensions sr = 400 μm and sz = 2.1 mm will be focused by this plasma lens onto an OTR screen approximately 2 cm downstream of the lens. The light from the OTR screen will be imaged into a streak camera in order to directly measure the correlation between z and sr within the beam. Status and progress on the experiment are reported.

TPAP005 Calculation of Residual Dose Rates and Intervention Scenarios for the LHC Beam Cleaning Insertions–Constraints and Optimization insertion, simulation, radiation, radioactivity 940
  • M. Brugger, O. Aberle, R.W. Assmann, D. Forkel-Wirth, H.G. Menzel, S. Roesler, H. Vincke
    CERN, Geneva
  Radiation protection of the personnel who will perform interventions in the LHC Beam Cleaning Insertions is mandatory and includes the design of equipment and the establishment of work procedures. Residual dose rates due to activated equipment are expected to reach significant values such that any maintenance has to be planned and optimized in advance. Three-dimensional maps of dose equivalent rates at different cooling times after operation of the LHC have been calculated with FLUKA. The simulations are based on an explicit calculation of induced radioactivity and of the transport of the radiation from the radioactive decay. The paper summarizes the results for the Beam Cleaning Insertions and discusses the estimation of individual and collective doses received by personnel during critical interventions, such as the exchange of a collimator or the installation of Phase 2. The given examples outline the potential and the need to optimize, in an iterative way, the design of components as well as the layout of the beam cleaning insertions. Furthermore, results of measurements and simulations of residual dose rates for a collimator test recently performed at the SPS are presented.  
TPAP014 Energy Deposition Studies for the Betatron Cleaning Insertion (IR7) of LHC insertion, simulation, proton, collimation 1386
  • M. Santana-Leitner, R.W. Assmann, A. Ferrari, M. Magistris, E. Tsoulou, V. Vlachoudis
    CERN, Geneva
  Two insertions (IR3, IR7) of the Large Hadron Collider (LHC) are dedicated to beam cleaning with the design goals of absorbing part of the primary beam halo and of the secondary radiation. The tertiary halo which escapes the collimation system in IR7 may heat the cold magnets at unacceptable levels, if no additional absorber is used. In order to assess the energy deposition in sensitive components, extensive simulations were run with the Monte Carlo cascade code FLUKA. The straight section and the dispersion suppressors of IR7 were fully implemented. A modular approach in the geometry definition and an extensive use of user-written programs allowed the implementation of all magnets and collimators with high precision, including flanges, steel supports and magnetic field. This paper provides the number and location of additional absorbers needed to keep the energy deposition in the coils of the magnets below the quenching limit.  
TPAP016 Energy Calibration of the SPS with Proton and Lead Ion Beams proton, sextupole, ion, alignment 1470
  • J. Wenninger, G. Arduini, C. Arimatea, T. Bohl, P. Collier, K. Cornelis
    CERN, Geneva
  The momentum of the 450 GeV/c proton beam of the CERN Super Proton Synchrotron was determined by a high precision measurement of the revolution frequencies of proton and lead ion beams. To minimize systematic errors the magnetic cycle of the SPS had to be rigorously identical for both beams, and corrections due to Earth tides had to be taken into account. This paper presents how the beam momentum was determined from the RF frequency for which the beams are centred in the machine sextupoles. The measured beam momentum is 449.16 ± 0.14 GeV/c for a nominal momentum of 450 GeV/c, and the accuracy is limited by systematic errors.  
TPAP018 Optics Studies of the LHC Beam Transfer Line TI8 optics, coupling, extraction, emittance 1578
  • J. Wenninger, G. Arduini, B. Goddard, D. Jacquet, V. Kain, M. Lamont, V. Mertens, J.A. Uythoven
    CERN, Geneva
  • Y.-C. Chao
    Jefferson Lab, Newport News, Virginia
  The optics of the newly commissioned LHC beam transfer line TI 8 was studied with beam trajectories, dispersion and profile measurements. Steering magnet response measurements were used to analyze the quality of the steering magnets and of the beam position monitors. A simultaneous fit of the quadrupole strengths was used to search for setting or calibration errors. Residual coupling between the planes was evaluated using high statistics samples of trajectories. Initial conditions for the optics at the entrance of the transfer line were reconstructed from beam profile measurements with Optical Transition Radiation monitors. The paper presents the various analysis methods and their errors. The expected emittance growth arising from optical mismatch into the LHC is evaluated.  
TPAP024 Decoupling Schemes for the Tevatron in the Presence of Skew Quadrupole Fields lattice, dipole, sextupole, optics 1850
  • C. Johnstone, P. Snopok
    Fermilab, Batavia, Illinois
  • M. Berz
    MSU, East Lansing, Michigan
  Funding: Work is supported by the U.S. Department of Energy under contract no DE-AC02-76CH03000.

With increasing demands for luminosity, optimal performance must be extracted from the existing Tevatron optics. We have, therefore, initiated a high-order dynamical study of the Tevatron to assess the performance, functionality and potential of the baseline lattice. This work describes the nonlinear or high-order performance of the Tevatron lattice with emphasis on the coupled and increased nonlinear behavior introduced by the significant skew quadrupole error in combination with conventional sextupole correction, a behavior still clearly evident after optimal tuning of available skew quadrupole circuits. An optimization study is then performed using different skew quadrupole families, and, importantly, local and global correction of the linear skew terms in maps generated by the code, COSY. A correction scheme, with two families locally correcting each arc and eight independent correctors outside the arc for global correction is shown to be optimal and dramatically improve the linear performance of the baseline Tevatron lattice.

TPAP027 Deterioration of the Skew Quadrupole Moment in Tevatron Dipoles Over Time coupling, dipole, alignment, monitoring 1967
  • M.J. Syphers, D.J. Harding
    Fermilab, Batavia, Illinois
  Funding: United States Department of Energy under Contract No. DE-AC02-76CH03000.

During the 20 years since it was first commissioned, the Fermilab Tevatron has developed strong coupling between the two transverse degrees of freedom. A circuit of skew quadrupole magnets is used to correct for coupling and, though capable, its required strength has increased since 1983 by more than an order of magnitude. In more recent years changes to the Tevatron for colliding beams operation have altered the skew quadrupole corrector distribution and strong local coupling become evident, often encumbering routine operation during the present physics run. Detailed magnet measurements were performed on each individual magnet during construction, and in early 2003 it was realized that measurements could be performed on the magnets in situ which could determine coil movements within the iron yoke since the early 1980's. It was discovered that the superconducting coils had become vertically displaced relative to their yokes since their construction. The ensuing systematic skew quadrupole field introduced by this displacement accounts for the required corrector settings and observed beam behavior. An historical account of the events leading to this discovery and progress toward its remedy are presented.

TPAP028 Observations of Strong Transverse Coupling in the Tevatron coupling, dipole, betatron, collider 2029
  • M.J. Syphers, G. Annala, D.A. Edwards, N.M. Gelfand, J.A. Johnstone, M.A. Martens, T. Sen
    Fermilab, Batavia, Illinois
  Funding: United States Department of Energy under Contract No. DE-AC02-76CH03000.

During the beginning of Run II of the Tevatron Collider it became apparent that a large skew quadrupole source, or sources, had developed in the superconducting synchrotron. Efforts to locate the current source of coupling were undertaken, with the eventual discovery that the main magnets had developed a systematic skew quadrupole moment over their lifetime. Over the past year, the magnets have been altered in place in an attempt to restore the systematic skew quadrupole moment to zero. Beam observations and their interpretations are presented, and remedial measures are discussed.

TPAP029 Measurements of Field Decay and Snapback Effect on Tevatron Dipole and Quadrupole Magnets injection, sextupole, dipole, octupole 2098
  • G. Velev, G. Ambrosio, G. Annala, P. Bauer, R. H. Carcagno, J. DiMarco, H.D. Glass, R. Hanft, R.D. Kephart, M.J. Lamm, M.A. Martens, P. Schlabach, C. Sylvester, M. Tartaglia, J. Tompkins
    Fermilab, Batavia, Illinois
  Since the beginning of 2002 an intensive measurement program has been performed at the Fermilab Magnet Test Facility to understand dynamic effects in the Tevatron magnets. Based on the results of this program a new correction algorithm was proposed to compensate for the decay of the sextupole field during the dwell at injection and for the subsequent field "snapback" during the first few seconds of the energy ramp. Beam studies showed that the new correction algorithm works better than the original one, and improves the Tevatron efficiency by at least 3%. The beam studies also indicated insufficient correction during the first 20 s of the injection plateau where an unexpected discrepancy of 0.15 sextupole units of extra drift was observed. This paper reports on the most recent measurements of the Tevatron dipoles field at the beginning of the injection plateau. Results on the field decay and snapback in the Tevatron quadrupoles are also presented.  
TPAP030 Tevatron Alignment Issues 2003-2004 dipole, alignment, closed-orbit, laser 2146
  • J.T. Volk, J. Annala, L. Elementi, N.M. Gelfand, K. Gollwitzer, J.A. Greenwood, M.A. Martens, C.D. Moore, A. Nobrega, A.D. Russell, T. Sager, V.D. Shiltsev, R. Stefanski, M.J. Syphers, G. Wojcik
    Fermilab, Batavia, Illinois
  Funding: U.S. Department of Energy under contract No. DE-AC02-76CH03000.

It was observed during the early part of Run II that dipole corrector currents in the Tevatron were changing over time. Measurement of the roll for dipoles and quadrupoles confirmed that there was a slow and systematic movement of the magnets from their ideal position. A simple system using a digital protractor and laptop computer was developed to allow roll measurements of all dipoles and quadrupoles. These measurements showed that many magnets in the Tevatron had rolled more than 1 milli-radian. To aid in magnet alignment a new survey network was built in the Tevatron tunnel. This network is based on the use of free centering laser tracker. During the measurement of the network coordinates for all dipole, quadrupole and corrector magnets were obtained. This paper discusses roll measurement techniques and data, the old and new Tevatron alignment network.

TPAP035 Energy Deposition Issues at 8 GeV H- Beam Collimation and Injection to the Fermilab Main Injector injection, kicker, proton, collimation 2372
  • A.I. Drozhdin, M.A. Kostin, N.V. Mokhov
    Fermilab, Batavia, Illinois
  The energy deposition and radiation issues at 8 GeV H- beam collimation in the beam transfer line and at stripping injection to the Fermilab Main Injector are analyzed. Detailed calculations with the STRUCT and MARS15 codes are performed on heating of collimators, stripping foils and other critical components, as well as on beam line and accelerator element radioactivation both at normal operation and accidental beam loss. Extraction of the unstripped part of the beam to the external beam dump and loss of the excited-state Ho atoms in the Main Injector are also studied.  
TPAP046 Towards an Optimization of the LHC Intersection Region using New Magnet Technology dipole, insertion, radiation, lattice 2920
  • P.M. McIntyre, A. Sattarov
    Texas A&M University, College Station, Texas
  • J.-P. Koutchouk
    CERN, Geneva
  An optimized design of the intersection region of LHC is presented. The starting point of the design is to move the quadrupole triplet to a minimum distance from the intersect – 12 m. The innermost quadrupole must accommodate substantial heat load from particles, and is designed using a structured cable that incorporates internal refrigeration with supercritical helium. Using the reduced aperture required by this closer spacing, Nb3Sn quadrupoles have been designed with gradients of 350-400 T/m for the triplet. The separation dipole utilizes a levitated-pole design that mitigates the extreme heat and radiation challenges for that application. The above technical elements have been incorporated into an optimized insertion design that minimizes ?* while significantly reducing sensitivities to errors in multipoles and alignment. The additional space that is opened in the lattice can be used to fully localize the optical design of the insertion so that it does not require corrections through the neighboring arcs.  
TPAP048 Optimization of the Phase Advance Between RHIC Interaction Points resonance, lattice, proton, luminosity 3031
  • R. Tomas
    CELLS, Bellaterra (Cerdanyola del Vallès)
  • W. Fischer
    BNL, Upton, Long Island, New York
  Funding: U.S. department of Energy.

We consider the scenario of having two identical Interaction Points (IPs) in the Relativistic Heavy Ion Collider (RHIC). The strengths of beam-beam resonances strongly depend on the phase advance between these two IPs and therefore certain phase advances could improve beam lifetime and luminosity. We compute the dynamic aperture as function of the phase advance between these IPs to find the optimum settings. The beam-beam interaction is treated in the weak-strong approximation and a complete non-linear model of the lattice is used. For the current RHIC proton working point (0.69,0.685) the design lattice is found to have the optimum phase advance. However this is not the case for other working points.

TPAP051 Principle of Global Decoupling with Coupling Angle Modulation coupling, simulation, injection, betatron 3132
  • Y. Luo, S. Peggs, F.C. Pilat, T. Roser, D. Trbojevic
    BNL, Upton, Long Island, New York
  Funding: Work supported by U.S. DOE under contract No. DE-AC02-98CH10886.

The global betatron decoupling on the ramp is an important issue for the operation of the Relativistic Heavy Ion Collider (RHIC). A new scheme coupling phase modulation is found. It introduces a rotating extra coupling into the coupled machine to detect the residual coupling. The eigentune responses are measured with a high resolution phase lock loop (PLL) system. From the minimum and maximum tune splits, the correction strengths are given. The time period occupied by one coupling phase modulation is less than 10 seconds. So it is a very promising solution for the global decoupling on the ramp. In this article the principle of the coupling phase modulation is given. The simulation with the smooth accelerator model is also done. The practical issues concerning its applications are discussed.

TPAP052 Possible Phase Loop for the Global Decoupling coupling, feedback, simulation, collider 3182
  • Y. Luo, P. Cameron, A. Della Penna, A. Marusic, S. Peggs, T. Roser, D. Trbojevic
    BNL, Upton, Long Island, New York
  • O.R. Jones
    CERN, Geneva
  Funding: Work supported by U.S. DOE under contract No. DE-AC02-98CH10886.

Besides two eigentunes Q1 and Q2 , two amplitude ratios r1 and r2 and two phase differences ∆ φ1 and ∆ φ2 are introduced for the global coupling observation. Simulations are carried out to check their behaviors in the process of the skew quadrupole strength scans. Some attractive features of the phase differences ∆ φ1,2 have been found, which are possibly useful for the global decoupling phase loop, or future global decoupling feedback. Analytical descriptions to these 6 quantities are described in the Twiss parameters through the linear coupling's action-angle parameterization, or in coupling coefficient through the linear coupling's Hamiltonian perturbation theory. Dedicated beam experiments are carried out at the Relativistic Heavy Ion Collider (RHIC) to check the global coupling observables from the phase lock loop (PLL) system. The six observables are measured under PLL driving oscillations during the 1-D and 2-D skew quadrupole scans. The experimental results are reported and discussions are given.

TPAP054 Helium Flow Induced Orbit Jitter at RHIC monitoring, heavy-ion, injection, emittance 3262
  • C. Montag, P. He, L. Jia, T. Nicoletti, T. Satogata, J. Schmalzle, T. Tallerico
    BNL, Upton, Long Island, New York
  Funding: Work performed under the auspices of the US Department of Energy.

Horizontal beam orbit jitter at frequencies around 10 Hz has been observed at RHIC for several years. The distinct frequencies of this jitter have been found at superconducting low-beta qudrupole triplets around the ring, where they coincide with mechanical modes of the cold masses. Recently, we have identified liquid helium flow as the driving force of these oscillations.

TPAT004 Strongly Asymmetric Beams at the University of Maryland Electron Ring (UMER) focusing, electron, diagnostics, emittance 892
  • S. Bernal, R.A. Kishek, P.G. O'Shea, B. Quinn, 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 standard operation of the University of Maryland electron ring employs symmetric strong focusing with magnetic quadrupoles, i.e., a FODO scheme whereby the zero-current betatron phase advances per period in the two transverse planes are equal or nearly so. Asymmetric focusing, on the other hand, employs quadrupoles with different strengths in a FODO cell. Typically, a small focusing asymmetry is implemented in most accelerators to set the operating point (horizontal and vertical zero-current tunes) in order to avoid resonances and/or compensate for edge focusing of bend magnets. Extreme asymmetry, however, is rarely, if at all, used. We review the motivation and theory of beam transport with general focusing asymmetry. We also present results of preliminary experiments and simulations with highly asymmetric focusing of a space-charge dominated electron beam in UMER.

TPAT005 Start to End Error Study for the SPIRAL2 Linac linac, emittance, diagnostics, beam-losses 934
  • R. Duperrier, D. Uriot
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  Funding: CEA

The possibility of a high intensity accelerator at GANIL, producing secondary beams of unprecedented intensity, is considered. The proposed driver for the SPIRAL2 project aims to accelerate a 5 mA deuteron beam up to 20 A.MeV and a 1 mA ion beam for q/A = 1/3 up to 14.5 A.MeV. It is a continuous wave regime linac, designed for a maximum efficiency in the transmission of intense beams and a tunable energy. This paper presents the error sensitivity study which has been performed for this linac in order to define the tolerances for the construction. The correction scheme and the expected losses are described.

TPAT007 RF Defocusing in Super-Conducting Structure with Constant Geometry focusing, space-charge 1042
  • Y. Senichev, R. Maier, N.E. Vasyukhin
    FZJ, Jülich
  Due to higher accelerating gradient in the super-conducting linac the RF defocusing factor plays significant role in the beam dynamics. Together with the space charge it is a main reason for the stability loss. Usually it is estimated in frame of the travelling wave formalism with synchronous motion. However, the super-conducting cavity is desirable to have the constant geometry, when synchronous motion is absent. In this case the quasi-synchronous phase velocity is adjusted by RF phasing. In this paper we investigate RF defocusing factor in absent of synchronism between the beam and the accelerating structure.  
TPAT018 Stability of Barrier Buckets with Short or Zero Barrier Separations resonance, synchrotron, dipole, beam-losses 1589
  • K.Y. Ng
    Fermilab, Batavia, Illinois
  A barrier bucket with small separation between the rf barriers (relative to the barrier widths) or even zero separation has its synchrotron tune decreasing rather slowly towards the boundary of the bucket. As a result, large area at the bucket edges can become unstable under the modulation of rf voltage and rf phase. Application is made to those barrier buckets used in the process of momentum mining on the issues of bunch-distribution distortion and particle loss.  
TPAT022 Future Plans for the Small Isochronous Ring space-charge, focusing, betatron, dipole 1778
  • E.P. Pozdeyev
    Jefferson Lab, Newport News, Virginia
  • F. Marti, R.C. York
    NSCL, East Lansing, Michigan
  • J.A. Rodriguez
    CERN, Geneva
  Funding: Work supported by NSF Grant #PHY-0110253 and DOE Contract DE-AC05-84ER40150.

The Small Isochronous Ring has been operational at Michigan State University since December 2003. It is used for experimental studies of the beam dynamics in high-intensity isochronous cyclotrons and synchrotrons at the transition energy. The operational experience with SIR has proven that the ring can be successfully used to study space charge effects in accelerators. The low velocity of beam particles in the ring allowed us to achieve a high accuracy of longitudinal profile measurements that is difficult to achieve in full-size accelerators. The experimental data obtained in the ring was used for validation of multi-particle, space-charge codes CYCO and WARP3D. Inspired by the solid performance of SIR in the isochronous regime, we consider options for expanding the scope of the beam physics studied in the ring. In this paper, we outline possible future experiments and discuss required modifications of the ring optics and hardware.

TPAT027 Measurement of Transverse Echoes in RHIC dipole, lattice, scattering, octupole 1955
  • W. Fischer, T. Satogata
    BNL, Upton, Long Island, New York
  • R. Tomas
    CELLS, Bellaterra (Cerdanyola del Vallès)
  Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886.

Beam echoes are a very sensitive method to measure diffusion, and longitudinal echo measurements were performed in a number of machines. In RHIC, for the first time, a transverse beam echo was observed after applying a dipole kick followed by a quadrupole kick. After application of the dipole kick, the dipole moment decohered completely due to lattice nonlinearities. When a quadrupole kick is applied at time T after the dipole kick, the beam re-cohered at time 2T thus showing an echo response. We describe the experimental setup and measurement results. In the measurements the dipole and quadrupole kick amplitudes, amplitude dependent tune shift, and the time between dipole and quadrupole kick were varied. In addition, measurements were taken with gold bunches of different intensities. These should exhibit different transverse diffusion rates due to intra-beam scattering.

TPAT030 Transverse Beam Matching Application for SNS emittance, SNS, linac, optics 2143
  • C. Chu, V.V. Danilov, D.-O. Jeon, M.A. Plum
    ORNL, Oak Ridge, Tennessee
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos, and Oak Ridge.

An automated transverse beam matching application has been developed for the Spallation Neutron Source (SNS) beam transport lines. The application is written within the XAL Java framework and the matching algorithm is based on the simplex optimization method. Other functionalities, such as emittance calculated from profile monitor measurements (adopted from a LANL Fortran code), profile monitor display, and XAL on-line model calculation, are also provided by the application. Test results obtained during the SNS warm linac commissioning will be reported. A comparison between the emittances obtained from this application and an independent Trace-3D routine will also be shown.

TPAT031 Painting Self-Consistent Beam Distributions in Rings SNS, space-charge, injection, lattice 2194
  • J.A. Holmes, S.M. Cousineau, V.V. Danilov
    ORNL, Oak Ridge, Tennessee
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos, and Oak Ridge.

We define self-consistent beam distributions to have the following properties: 1) time-independence or periodicity, 2) linear space charge forces, and 3) maintainance of their defining shape and density under all linear transformations. The periodic condition guarantees zero space-charge-induced halo growth and beam loss during injection. Some self-consistent distributions can be manipulated into flat, or even point-like, beams, which makes them interesting to colliders and to heavy-ion fusion. This paper presents methods for painting 2D and 3D self-consistent distributions and for their manipulation to produce flat and point-like beams.

TPAT048 The Transverse Nonlinear Tune Shift as Stabilising Factor in Halo Creation in Space Charge Dominated Beam resonance, space-charge, focusing, linac 3004
  • N.E. Vasyukhin, Y. Senichev, R. Tölle
    FZJ, Jülich
  Funding: We acknowledge the support of the European Community-Research Infrastructure Activity under the FP6 "Structuring the European Research Area" program (CARE, contract number RII3-CT-2003-506395).

One of the most important problems for space charge dominated beam in the low energy part of superconducting linac is halo creation. Many authors show one of the key effects in halo creatiation is parametric resonance due to the mismatched beta-function oscillation (between core and particle). To estimate parametric resonance conditions the nonlinear tune shift for binomial distributed beam is described theoretically in this article. Simultaneously the beam dynamics simulation 3D PIC code was developed. The transverse oscillation frequencies compared with parametric resonance criteria. As a result the recommendation for space charge shift is concluded to minimize halo creation.

TPAT049 Comparison of Beam Dynamic in Different Superconducting Options of Low Energy High Intense Linac focusing, linac, simulation, space-charge 3058
  • N.E. Vasyukhin, Y. Senichev, R. Tölle
    FZJ, Jülich
  Funding: We acknowledge the support of the European Community-Research Infrastructure Activity under the FP6 "Structuring the European Research Area" program (CARE, contract number RII3-CT-2003-506395).

At present the superconducting proton linacs have obvious applications in energy range ~100-1000 MeV. For the lower energy the comprehensive investigations are required. In this article the various variants of superconducting options from 3MeV up to 100MeV are discussed. The considered variants include both the conventional combination of half-wave and spoke cavity with quadrupoles and new schemes. In conclusion the table of major parameters for different structures is given.

TPAT057 Observations of UHF Oscillations in the IPNS RCS Proton Bunch acceleration, synchrotron, proton, extraction 3375
  • J.C. Dooling, F.R. Brumwell, G.E. McMichael, S. Wang
    ANL, Argonne, Illinois
  Funding: This work is supported by the U.S. Department of Energy under contract no. W-31-109-ENG-38.

The Intense Pulsed Neutron Source (IPNS) Rapid Cycling Synchrotron (RCS) accelerates 3.2x 1012 protons from 50 MeV to 450 MeV in a single bunch (h=1) at 30 Hz. The rf frequency varies from 2.21 MHz to 5.14 MHz during the 14.2 ms acceleration interval. To maintain stability of the bunch, phase modulation is introduced to the rf at approximately twice the synchrotron frequency (synchrotron tune is 0.0014). This phase modulation causes a parametric quadrupole oscillation to develop in the bunch, and as this occurs, the bunch spectrum shows a significant increase in high frequency content. Without phase modulation, the beam experiences an instability which results in the loss of a large fraction of the charge 2-4 ms prior to extraction. It is unclear if the stability imparted to the beam by phase modulation comes from the quadrupole oscillation or from the high frequency excitation. A longitudinal tracking code is presently being modified to include amplitude and phase modulation of the bunch. The numerical analysis will be used to compare growth rates with those observed in the machine. The results of this analysis will be important as we introduce second harmonic rf with a new third cavity in the RCS later in 2005.

TPAT061 Accurate Iterative Analysis of the K-V Equations lattice, emittance, simulation, focusing 3535
  • O.A. Anderson
    LBNL, Berkeley, California
  Funding: Supported in part by the U.S. Department of Energy under Contract No. DE-AC03-76SF00098.

Previous solutions of the K-V equations have either yielded poor accuracy or have been complex and difficult to follow. We describe a new approach, simple in concept, easy to use, with accuracy substantially improved over previous treatments. The results are given in the same form as the smooth approximation but include a few correction terms obtained from the field gradient integrated along the axis of a quadrupole cell. The input quantities–quadrupole field, beam current, and emittance–yield the average beam radius, the maximum envelope excursion, and the depressed and undepressed tunes. For all values of the input parameters, the results are much closer to the exact values from simulations than are results from the smooth approximation. For example, with the parameters adjusted for an exact phase advance of 83.4 degrees and 50% tune depression, both tunes are in error by less than 0.5%–over 22 times better than the smooth approximation. The error in maximum radius is 0.04%, improved by a factor of 80. The new method and its application to a wide range of cases will be presented.

TPAT084 LIFETRAC Code for the Weak-Strong Simulation of the Beam-Beam Effect in Tevatron betatron, simulation, optics, antiproton 4138
  • A. Valishev, Y. Alexahin, V. Lebedev
    Fermilab, Batavia, Illinois
  • D.N. Shatilov
    BINP SB RAS, Novosibirsk
  Funding: Work supported by the Universities Research Assos., Inc., under contract DE-AC02-76CH03000 with the U.S. Dept. of Energy.

A package of programs for weak-strong simulation of beam-beam effects in hadron colliders is described. Accelerator optics parameters relevant to the simulation are derived from beam measurements and calculations are made using OptiM optics code. The key part of the package is the upgraded version of the LIFETRAC code which now includes 2D coupled optics, chromatic modulation of beta-functions, non-Gaussian shape of the strong bunches and non-linear elements for beam-beam compensation. Parallel computations are used and in the case of the Tevatron (2 main IPs + 70 parasitic IPs) the code has a productivity of ~1·1010 particles*turns/day on a 32-node cluster of Pentium IV 1.8 GHz processors.

TPPE013 Simulations of Solenoid and Electrostatic Quadrupole Focusing of High Intensity Beams from ECR Ion Source at NSCL focusing, space-charge, emittance, simulation 1336
  • Q. Zhao, A.I. Balabin, M. Doleans, F. Marti, J.W. Stetson, X. Wu
    NSCL, East Lansing, Michigan
  Solenoidal focusing has been widely used to focus beams at various injectors for its axisymmetric focusing with reasonable effectiveness. Experiments and simulations have shown that space charge effects can significantly deteriorate the beam quality when solenoidal focusing is used in a multi-component beam. This is due to the magnetic focusing strength dependence on the beam charge-to-mass ratio. Electrostatic quadrupole focusing has been explored as an alternate option at NSCL for the injection line of the superconducting cyclotron. We present in this paper the results of simulations for both systems. The electrostatic quadrupoles have been optimized to reduce the radial dependent aberrations and to increase the transmission efficiency.  
TPPE033 A Comparison of Electrostatic and Magnetic Focusing of Mixed Species Heavy Ion Beams at NSCL/MSU sextupole, focusing, cyclotron, ion 2281
  • J.W. Stetson, G. Machicoane, F. Marti, P. Miller, M. Steiner, P.A. Zavodszky
    NSCL, East Lansing, Michigan
  • Yu. Kazarinov
    JINR, Dubna, Moscow Region
  Funding: This work has been supported by National Science Foundation under grant PHY-0110253.

Experience at the National Superconducting Cyclotron Laboratory has shown the first focusing element after the electron cyclotron resonance ion source (ECRIS), before the beam is analyzed by a magnetic dipole, to be critical to subsequent beam transport and matching. Until 2004, both ion sources at the NSCL used a solenoid as this first focusing element. Observation of hollow beam formation led to further analysis and the decision to replace the solenoid with an electrostatic quadrupole triplet on a test basis [1]. Substantial increases in net cyclotron output were achieved, leading us to adopt electrostatic quadrupole focusing as the permanent configuration. In addition, a sextupole magnet was installed in this beam line. Motivations for these changes and results of operating experience are discussed.

TPPE044 Upgrade of the Fermilab/NICADD Photoinjector Laboratory laser, emittance, linac, electron 2848
  • P. Piot, H. Edwards
    Fermilab, Batavia, Illinois
  • M. Huening
    DESY, Hamburg
  • T. W. Koeth
    Rutgers University, The State University of New Jersey, Piscataway, New Jersey
  • J.L. Li, R. Tikhoplav
    Rochester University, Rochester, New York
  Funding: This work was supported by Universities Research Association Inc. under contract DE-AC02-76CH00300 with the U.S. DOE, and by NICADD.

The Femilab/NICADD photoinjector laboratory (FNPL) is a 16 MeV electron accelerator dedicated to beam dynamics and advanced accelerator studies. FNPL will soon be capable of operating at 50 MeV, after the installation of a high gradient TESLA cavity. In this paper we present the foreseen design for the upgraded facility along with its performance. We discuss the possible application of 50 MeV beam including the possible use of FNPL as an injector for the superconducting module and test facility (SM&TF).

TPPE050 Beam Injection in Recirculator SALO injection, electron, gun, focusing 3109
  • I.S. Guk, A. Dovbnya, S.G. Kononenko, F.A. Peev, A.S. Tarasenko
    NSC/KIPT, Kharkov
  • J.I.M. Botman, M.J. Van der Wiel
    TUE, Eindhoven
  Possible antetypes of injectors for electron recirculator SALO,* intended for nuclear-physical research, are analyzed. The plan injection of beams in recirculator is offered. Expected parameters of beams are designed.

*I.S. Guk, A.N. Dovbnya, S.G. Kononenko, A.S. Tarasenko, M. van der Wiel, J.I.M. Botman, NSC KIPT accelerator on nuclear and high energy physics, Proceedings of EPAC 2004, Lucerne, Switzerland, p. 761-764.

TPPE054 Status of the Injection System for the Australian Synchrotron Project booster, synchrotron, injection, sextupole 3271
  • S.P. Møller, H. Bach, F. Bødker, T.G. Christiansen, A. Elkjaer, S. Friis-Nielsen, N. Hauge, J. Kristensen, L.K. Kruse, S.P. Møller, B.R. Nielsen
    Danfysik A/S, Jyllinge
  DANFYSIK A/S designs and builds the complete injection system for the Australian Synchrotron Project. The full-energy booster will accelerate the beam from the injection energy of 100 MeV. to a maximum of 3.0 GeV. The booster is using combined function magnets. The status of the project is presented.  
TPPE056 Emittance Measurement with Upgraded RF Gun System at SPring-8 emittance, laser, gun, simulation 3348
  • A. Mizuno, H. Dewa, H. Hanaki, T. Taniuchi, H. Tomizawa
    JASRI/SPring-8, Hyogo
  • M. Uesaka
    UTNL, Ibaraki
  A single cell S-band RFgun has been developed at the SPring-8 since 1996. The minimum normalized beam emittance, measured with double slits' scanning method in 2002, was 2.3 pi mm mrad at the exit of the gun cavity with charge of 0.1 nC/bunch. In 2004, we installed a following accelerator structure to investigate beam behavior of the whole injector system. In this paper, we report emittance measurement results of upgraded system, using variable quadrupole magnet method. The minimum emittance of 2.0 pi mm mrad with a net charge of 0.14 nC/bunch were able to be measured.  
TPPE058 Dual Feed RF Gun Design for the LCLS gun, coupling, laser, dipole 3432
  • L. Xiao, R.F. Boyce, D. Dowell, Z. Li, C. Limborg-Deprey, J.F. Schmerge
    SLAC, Menlo Park, California
  Funding: Work supported by the U.S. DOE under contract DE-AC03-76SF00515.

In order to remove the dipole field introduced by the coupler in existing S-band BNL/SLAC/UCLA 1.6 cell rf gun, a dual feed design for the LCLS RF gun is proposed together with several significant changes. The improvements include adopting Z-coupling instead of ?-coupling for easier machining and reducing heating, increasing the 0-and ?-mode separation from 3.4 to 15 MHz to reduce the amplitude of the 0 mode, incorporating race-track cavity shape to minimize the quadruple fields, increased cooling for operation at 120Hz and other small changes to improve performance and diagnostic capabilities. The new design has been modeled with the parallel finite element eigenmode solver Omega3P to provide the desired RF parameters and to generate the gun cavity dimensions needed for fabrication.

TPPP002 Global-Beta Measurement and Correction at the KEKB Rings optics, betatron, sextupole, closed-orbit 802
  • A. Morita, H. Koiso, Y. Ohnishi, K. Oide
    KEK, Ibaraki
  The global-beta correction is a part of the optics corrections which are performed to regularize the ring optics for the luminosity tunings. The global-beta measurement is performed by the reconstruction of the beta function from the set of the single kick orbits generated by the 6 kinds of the steering magnets. The distortion of the beta fucntion and the phase advance are corrected by the global beta correction using the fudge factors of power supplies of quadrupole magnets. These correction scheme are successfully working. In the typical case, the r.m.s. of the beta function beat and the betatron tune difference are corrected within 5% and 0.0005, respectively. In the luminosity run, we can operate the low energy ring(LER) with the horizontal betatron tune very close to half-integer(45.5050). In this paper, we will report in detail the global-beta measurement and correction techniques and its performance in the KEKB operation.  
TPPP003 Lattice Upgrade Plan for Crab Crossing at the KEKB Rings lattice, luminosity, optics, coupling 865
  • A. Morita, K. Egawa, K. Hosoyama, H. Koiso, T. Kubo, M. Masuzawa, K. Ohmi, K. Oide, R. Sugahara, M. Yoshida
    KEK, Ibaraki
  We plan to install two superconducting crab cavities into the rings at Janyary, 2006. In our plan, we will install one crab cavity per one ring into the NIKKO straight section where the cryogenic infrastructure is already operated for the superconducting accelerating cavities. In order to obtain the correct crabbing angle at the interaction point(IP), we have to enlarge the horizontal beta function(200m for HER) and have to adjust the horizontal phase advance between the IP and the cavity installation point. In this paper, we will report the lattice modified for the crab crossing and the study results about the single beam dynamics.  
TPPP012 A Study of the Effect of Beam-Beam Interactions on CESR Optics electron, positron, lattice, betatron 1275
  • J.A. Crittenden, M.G. Billing
    Cornell University, Department of Physics, Ithaca, New York
  • D. L. Rubin
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  Funding: National Science Foundation.

The CESR storage ring facility has begun operation in an energy region which allows high-statistics investigation of charm-quark bound states. Experience during the first year has shown that the effects of parasitic crossings in the pretzel orbits present an important factor in injection efficiency, in the beam lifetime and stored current limits. We compare the results of beam dynamics and tracking calculations which quantify the effects of these parasitic crossings on optics and dynamic aperture for the injected and stored trajectories to observations of beam behavior.

TPPP024 Experimental Study of Crossing-Angle and Parasitic-Crossing Effects at the PEP-II e+e- Collider luminosity, simulation, electron, optics 1874
  • W. Kozanecki
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  • Y. Cai, J. Seeman, M.K. Sullivan
    SLAC, Menlo Park, California
  • I.V. Narsky
    CALTECH, Pasadena, California
  In a series of dedicated accelerator experiments, we have measured the dependence of the PEP-II luminosity performance on small horizontal crossing angles and on the horizontal separation at the first parasitic crossing. The experiment was carried out by varying the IP angle of one of the beams in two different bunch patterns, one with and one without parasitic crossings. The experimental measurements show satisfactory agreement with three-dimensional beam-beam simulations.  
TPPP031 A Proposal for a New HOM Absorber in a Straight Section of the PEP-II Low Energy Ring impedance, dipole, damping, scattering 2173
  • S.P. Weathersby, M. Kosovsky, N. Kurita, A. Novokhatski, J. Seeman
    SLAC, Menlo Park, California
  Funding: Work supported by the U.S. Department of Energy under contract number DE-AC03-76SF00515.

Attainment of high luminosity in storage ring colliders necessitates increasing stored currents and reducing bunch lengths. Consequently, intense beam fields will scatter more power into higher order modes from beam line sources such as collimators, masks and tapers. This power penetrates into sensitive components such as a bellows, causing undesirable heating and limits machine performance. To overcome this limitation we propose incorporating ceramic absorbers in the vicinity of the bellows to damp beam induced modes while preserving a matched impedance to the beam. This is accomplished with an absorber configuration which damps TE dipole and quadrupole traveling waves while preserving TM monopole propagation. A scattering parameter analysis is presented utilizing properties of commercial grade ceramics and indicates a feasible solution.

TPPP032 Proposal for a Multi-Use Test Beam Area in the SLAC B-Line linac, optics, target, emittance 2221
  • P. Emma, L.D. Bentson, R.A. Erickson, H. Fieguth, J. Seeman, A. Seryi
    SLAC, Menlo Park, California
  Funding: Work supported by U.S. Department of Energy contract DE-AC02-76SF00515.

With the impending construction of the Linac Coherent Light Source (LCLS) at SLAC, displacing the well-used Final Focus Test Beam (FFTB) area, there is growing interest in developing a new test beam facility, available during LCLS operations and located in the old B-Line tunnel at the end of the linac. The success of the Sub-Picosecond Pulse Source (SPPS) and the desire to preserve this capacity suggests a new beamline with similar or improved electron beam quality, including bunch length compression to 10 microns. Beam availability during LCLS operations requires a new 1.2-km bypass line connecting the 2/3-point of the linac with the B-Line. A second operating mode, with LCLS not in use, involves a trajectory directly from the end of the linac to the B-line. This feature provides the highest beam quality at 30 GeV, and also allows a possible third operational mode by deflecting a few of the very high-brightness 120-Hz, 14-GeV LCLS bunches at low rate (1-10 Hz) into the B-line. Finally, linear collider research can be carried out in a short final focus system at the end of the B-Line, capable of producing a 70-nm rms beam size. We describe a possible design for these systems.

TPPP044 Interaction Region Design for the Electron-Light Ion Collider ELIC electron, synchrotron, synchrotron-radiation, radiation 2824
  • C. Montag
    BNL, Upton, Long Island, New York
  • S.A. Bogacz, Y.S. Derbenev, L. Merminga
    Jefferson Lab, Newport News, Virginia
  Funding: Work performed under the auspices of the US Department of Energy.

The Electron-Light Ion Collider ELIC proposed by Jefferson Lab aims at very high luminosities for collisions of 150 GeV protons on 7 GeV electrons. To achieve these high luminosities, very strong low-beta focusing of low-emittance beams is required. Taking advantage of the unequal design proton beam emittances in the two transverse planes, an interaction region design based on superconducting quadrupole doublets has been deveoped. Compared with the original design, this scheme provides larger beam apertures at lower magnetic fields, while potentially doubling the luminosity.

TPPP050 Novel Muon Cooling Channels Using Hydrogen Refrigeration and High Temperature Superconductor beam-cooling, simulation, superconducting-magnet, dipole 3126
  • L. DelFrate, E. Barzi, D. Turrioni
    Fermilab, Batavia, Illinois
  • M. Alsharo'a, R.P. Johnson, M. Kuchnir
    Muons, Inc, Batavia
  Funding: This work was supported in part by DOE STTR grant DE-FG02-04ER86191.

Ionization cooling, a method for shrinking the size of a muon beam, requires a low Z energy absorber, high-field magnets, and high gradient RF. It is proposed to use one gaseous hydrogen system to provide ionization energy loss for muon beam cooling, breakdown suppression for pressurized high-gradient RF cavities, and refrigeration for superconducting magnets and cold RF cavities. We report progress on the design of a cryostat and refrigeration system that circulates hydrogen through magnetic coils, RF cavities, and the absorber volume to achieve a safe, robust means to enable exceptionally bright muon beams. We find that the design can be greatly simplified if a high temperature superconductor can be used that has the capability to carry adequate current in fields above 10 T at a temperature above 33 K, the critical temperature of hydrogen.

TPPP052 Simulations of a Gas-Filled Helical Muon Beam Cooling Channel simulation, emittance, focusing, beam-cooling 3215
  • K. Yonehara, D.M. Kaplan
    Illinois Institute of Technology, Chicago, Illinois
  • K. Beard, S.A. Bogacz, Y.S. Derbenev
    Jefferson Lab, Newport News, Virginia
  • R.P. Johnson, K. Paul, T.J. Roberts
    Muons, Inc, Batavia
  Funding: This work was supported in part by DOE STTR/SBIR grants DE-FG02-02ER86145 and 03ER83722.

A helical cooling channel (HCC) has been proposed to quickly reduce the six-dimensional phase space of muon beams for muon colliders, neutrino factories, and intense muon sources. The HCC is composed of a series of RF cavities filled with dense hydrogen gas that acts as the energy absorber for ionization cooling and suppresses RF breakdown in the cavities. Magnetic solenoidal, helical dipole, and helical quadrupole coils outside of the RF cavities provide the focusing and dispersion needed for the emittance exchange for the beam as it follows a helical equilibrium orbit down the HCC. In the work presented here, two Monte Carlo programs have been developed to simulate a HCC to compare with the analytic predictions and to begin the process of optimizing practical designs that could be built in the near future. We discuss the programs, the comparisons with the analytical theory, and the prospects for a HCC design with the capability to reduce the six-dimensional phase space emittance of a muon beam by a factor of over five orders of magnitude in a linear channel less than 100 meters long.

TPPP056 MANX, A 6-D Muon Cooling Demonstration Experiment emittance, dipole, collider, factory 3331
  • T.J. Roberts, M. Alsharo'a, P.M. Hanlet, R.P. Johnson, M. Kuchnir, K. Paul
    Muons, Inc, Batavia
  • C.M. Ankenbrandt, A. Moretti, M. Popovic, V. Yarba
    Fermilab, Batavia, Illinois
  • D.M. Kaplan, K. Yonehara
    Illinois Institute of Technology, Chicago, Illinois
  Funding: This work was supported in part by DOE SBIR grant DE-FG02-04ER84015.

Most ionization cooling schemes now under consideration are based on using many large flasks of liquid hydrogen energy absorber. One important example is the proposed Muon Ionization Cooling Experiment (MICE), which has recently been approved to run at the Rutherford Appleton Laboratory (RAL). In the work reported here, a potential muon cooling demonstration experiment based on a continuous liquid energy absorber in a helical cooling channel (HCC) is discussed. The original HCC used a gaseous energy absorber for the engineering advantage of combining the energy absorption and RF energy regeneration in hydrogen-filled RF cavities. In the Muon And Neutrino eXperiment (MANX) that is proposed here, a liquid-filled HCC is used without RF energy regeneration to achieve the largest possible cooling rate in six dimensions. In this case, the magnetic fields of the HCC must diminish as the muons lose momentum as they pass through the liquid energy absorber. The length of the MANX device is determined by the maximum momentum of the muon test beam and the maximum practical field that can be sustained at the magnet coils. We have studied a 3 meter-long HCC example that could be inserted between the MICE spectrometers at RAL.

TPPT004 A 175 MHz RFQ Design for IFMIF Project rfq, insertion, linac, simulation 904
  • S. Maebara, S. Moriyama, M.S. Sugimoto
    JAERI, Ibaraki-ken
  • M.S. Saigusa, Y. Saitou
    Ibaraki University, Electrical and Electronic Eng., Ibaraki
  International Fusion Materials Irradiation Facility (IFMIF) is an accelerator-based neutron irradiation facility employing the D-Li stripping reaction, to produce the neutron field similar to the D-T Fusion reactor (2MW/m2,20 dpa/year for Fe). The required beam current of 250 mA is realized by two beam lines of 125mA, and the output energies at injector,RFQ and DTL were designed to be 0.1, 5 and 40 MeV,respectively. The operation frequency of 175MHz was selected to accelerate the large current of 125mA. After an intensive beam simulation, the RFQ with a total length of 12m was designed to keep the minimum emittance growth with the RF injection power of 2.3MW CW. For such a 175MHz RFQ, a design for RF input coupler with loop antenna and co-axial window, supplying RF power shared by 3 x 4 ports, was conducted by using the 3-D electromagnetic code of MW-Studio. In order to withstand the voltage exceeding 200kW CW per one loop antenna, the co-axial line of 4 1/16” diameter is necessary, and it is found that the electric field distortion factor less than 1% can be achieved in beam bore only by employing the 4-loop antenna configuration providing the same power for each quadrants.  
TPPT019 Numerical Study of Coupling Slot Effects on Beam Dynamics in Industrial Accelerator Prototype coupling, simulation, electron, injection 1622
  • V.V. Tarnetsky, V. Auslender, I. Makarov, M.A. Tiunov
    BINP SB RAS, Novosibirsk
  Funding: The work is supported by ISTC grant #2550.

At Budker INP, the work is in progress on development of high-efficiency, high-power electron accelerator named ILU-12. The accelerator has a modular structure and consists of a chain of accelerating cavities connected by on-axis coupling cavities with coupling slots in the common walls (the coupling constant is about 0.08). Main parameters of the accelerator are: operating frequency of 176 MHz, electron energy of up to 5 MeV, average beam power of 300 kW. The paper presents results of 3D electromagnetic field numerical simulations for ILU-12 accelerating structure with recovery of quadrupole filed disturbance because of large coupling holes. The results show that accelerating cell geometry chosen eliminates coupling slot influence on the beam dynamics.

TPPT022 The Structure of the High Frequency Focusing Cells in Linear Ion Accelerators focusing, ion, acceleration, proton 1796
  • V.A. Bomko, O.F. Dyachenko, A.P. Kobets, E.D. Marynina, Z.O. Ptukhina, S.S. Tishkin, B.V. Zajtsev
    NSC/KIPT, Kharkov
  The versions of the high frequency quadrupole doublets (RFQD) for proton and heavy ion linear accelerators are discussed. Advantages of focusing of this type over magnetic quadrupoles lie in the simplicity of the structure and high efficiency and reliability of focusing. In the multi-gap structures, focusing periods contain a sequence of focusing and accelerating cells. The elaborated technique of the local cell adjustment provides the high acceleration rate. Various RFQD versions for the specific peculiarities of accelerating structures are discussed. Application of the RF-quadrupole doublets in the spoke cavity, CCDTL and Crossbar structures will allow the application of superconductive cavities for proton acceleration in the range of intermediate energies of 5-100 MeV. In the interdigital H-structures, the application of RFQDs will allow to increase the efficiency of ion beam focusing and to expand the energy range of the ions being accelerated over 10 MeV/u.  
TPPT031 Coupler Design for the LCLS Injector S-Band Structures dipole, emittance, multipole, linac 2176
  • Z. Li, L.D. Bentson, J. Chan, D. Dowell, C. Limborg-Deprey, J.F. Schmerge, D.C. Schultz, L. Xiao
    SLAC, Menlo Park, California
  Funding: Work supported by the U.S. DOE Contract No. DE-AC03-76SF00515.

The LCLS injector is required to provide a 1-nC, 10-ps bunch with a normalized rms transverse projected emittance of less than 1.0-μm. The LCLS beam is generated and accelerated in a 1.6-cell S-band RF gun to 6-MeV followed by two SLAC 3-m S-band accelerator structures to further accelerate the beam to 135 MeV to move it out of the space-charge dominated regime. In the SLAC S-band structures, the RF power feed is through a single coupling-hole (single-feed coupler) which results in a field asymmetry. The time dependent multipole fields in the coupler induce a transverse kick along the bunch and cause the emittance to increase above the LCLS specification. To meet the stringent emittance requirements for the injector, the single-feed couplers will be replaced by a dual-feed racetrack design to minimize the multipole field effects. We will present detailed studies of the multipole fields in the S-band coupler and the improvements with the dual-feed racktrack design using the parallel finite element eigenmode solver Omega3P.

TPPT032 Modifications on RF Components in the LCLS Injector gun, emittance, cathode, linac 2233
  • C. Limborg-Deprey, D. Dowell, Z. Li, J.F. Schmerge, L. Xiao
    SLAC, Menlo Park, California
  Funding: This work was supported by U.S. Department of Energy, contract No. DE-AC03-76SF00515A06.

Design of the first generation LCLS injector has now been completed. Components are currently under fabrication and their installation is planned for 2006. We discuss the last modifications made on both the 1.6 cell S-Band RF gun and the SLAC S-Band accelerating structures to minimize the beam emittance. We present results from PARMELA computations which justify those modifications, in particular the suppression of the time dependent dipole and quadrupole kicks. Geometry changes to increase the mode separation between the 0 and PI modes are also presented. For the initial geometry with a mode separation of 3.5MHz, the emittance can increase if the appropriate injection time along the klystron pulse is not chosen. For a mode separation of 15MHz, this problem is minimized and the beam dynamics are improved leading to a substantial reduction of total projected emittance.

TPPT063 Higher-Order-Mode Damping of L-Band Superconducting Cavity using a Radial-Line HOM Damper damping, simulation, linac, dipole 3606
  • K. Umemori, M. Izawa, K. Saito, S. Sakanaka
    KEK, Ibaraki
  For the energy recovery linacs, strong damping of higher-order-modes (HOMs) is indispensable to avoid beam breakup instabilities. We studied a new HOM damping scheme using a radial-line HOM damper with a choke structure. Both models of the radial-line damper and the TESLA-type 9-cell cavity were prepared and the HOM characteristics of this scheme were experimentally investigated. Measurement results showed a promising performance of the radial-line HOM damper.  
TPPT096 Cryomodule Design for a Superconducting Linac with Quarter-Wave, Half-Wave, and Focusing Elements vacuum, alignment, linac, focusing 4317
  • M. J. Johnson, J. Bierwagen, S. Bricker, C. Compton, P. Glennon, T.L. Grimm, W. Hartung, D. Harvell, A. Moblo, J. Popielarski, L. Saxton, R.C. York, A. Zeller
    NSCL, East Lansing, Michigan
  The low-energy section of the driver linac for the proposed Rare Isotope Accelerator (RIA) incorporates the following superconducting elements: quarter-wave resonators, half-wave resonators, and 9 T solenoids. A prototype cryomodule has been designed to house all of these elements. A 31 T/m superferric quadrupole is also included as an alternative focusing element, since its stray magnetic field is more easily shielded. The cryomodule design is based on the RIA v/c=0.47 prototype cryomodule that was successfully tested in 2004.* The design uses a titanium rail structure to support the beam line elements. The beam line assembly is done in a class 100 clean room to maintain resonator cleanliness for optimal high-field performance. The cavities will be equipped with RF input couplers, tuners, and magnetic shields. High Tc current leads are used for both magnets. The cryomodule design takes into account static heat leak requirements and alignment tolerances for the beam line elements. A heat exchanger and J-T throttle valve will be used to provide a continuous supply of liquid helium for 2 K operation.

*T.L. Grimm et al., "Experimental Study of an 805 MHz Cryomodule for the Rare Isotope Accelerator", in Proceedings of the XXII International Linear Accelerator Conference, Lubeck, Germany (2004).

TOPE001 Experience with the TTF-2 electron, linac, beam-transport, undulator 1
  • L. Lilje
    DESY, Hamburg
  The TESLA Test Facility in its second phase (TTF-2) serves two main purposes: It is a testbed for the superconducting RF technology for the International Linear Collider as well as a user facility providing a VUV-FEL beam for experiments using synchrotron light. The presentation will review the progress on the superconducting RF technology. This includes tests on individual cavities as well as full accelerating modules. First experiences with the setup of TTF-2 will be presented. Among others, the measurements of higher order modes in the superconducting cavities are presented. Measurements of the beam properties will be shown.  
TOPE003 Results from DR and Instrumentation Test Facilities damping, emittance, laser, coupling 305
  • J.U. Urakawa
    KEK, Ibaraki
  The KEK Accelerator Test Facility (ATF) is a 1.3GeV storage ring capable of producing ultra-low emittance electron beams and has a beam extraction line for ILC R&D. The ATF has proven to be an ideal place for researches with small, stable beams. 2x1010 single bunch and low current 20 bunch-train with 2.8nsec bunch spacing have been extracted to develop Nano-Cavity BPM’s, FONT, Nano Beam Orbit handling (FEATHER), Optical Diffraction Radiation (ODR) monitor, a precision multi-bunch laser-based beam profile monitor and polarized positron beam generation via backward-Compton scattering by the international collaboration. A set of three cavity BPM's is installed in the ATF extraction line on a set of extremely stiff supports. The KEK group installed another set of three BPM's, with their own support mechanism. The full set of 6 will prove extremely useful. In the DR (Damping Ring), we are researching the fast ion instability, micro-wave instability with four sets of damping wiggler and developing pulsed laser wire monitor, X-ray SR monitor, very fast kicker with about 1nsec rise/fall time to make ILC beam. I will report the recent results on above R&D’s.  
WPAE017 Installation of the LHC Long Straight Sections (LSS) insertion, shielding, injection, vacuum 1563
  • S. Bartolome-Jimenez, G. Trinquart
    CERN, Geneva
  The LHC long straight sections (LSS) serve as experimental or utility insertions. There are two high luminosity experimental insertions located at points 1 and 5 and two more experimental insertions at points 2 and 8 which also contain the injection systems. The beams only cross at these four locations and are focused by superconducting low-beta triplets. Insertions 3 and 7 each contain two collimation systems. Insertion 4 contains two RF systems. Insertion 6 contains the beam dumping system. The installation of the LSS is a challenge due to the compact layout that characterises these areas and the difficulties related to the underground work mainly in zones of restricted access. Specific devices are required for handling and installing various heavy and voluminous elements. This paper reviews the installation scenarios, describes the sequences presently planned and highlights the potential problem areas. The particular case of sector 7-8 where the LSS elements will be installed in parallel with the cryogenic distribution line (QRL) is used as an example of a ‘rapid’ installation scheme to illustrate how resources are used. The consequences of possible shortcuts are also mentioned.  
WPAE021 Short Straight Sections in the LHC Matching Sections (MS SSS): An Extension of the Arc Cryostats To Fulfill Specific Machine Functionalities vacuum, insertion, collider, lattice 1724
  • V. Parma, H. Prin
    CERN, Geneva
  • fl. Lutton
    IPN, Orsay
  Funding: IPN-CNRS, 15 rue Georges Clémenceau 91406 ORSAY, France.

The LHC insertions require 50 specific superconducting quadrupoles, operating in boiling helium at 4.5 K and housed in individual cryostats to form the MS Short Straight Sections (MS SSS). The quadrupoles and corrector magnets are assembled in 8 families of cold masses, with lengths ranging from 5 to 11 m and weights ranging from 60 to 140 kN. The MS SSS need to fulfil specific requirements related to the collider topology, its cryogenic layout and the powering scheme. Most MS SSS are standalone cryogenic and super-conducting units, i.e. they are not in the continuous arc cryostat, and therefore need dedicated cryogenic and electrical feeding. Specially designed cryostat end-caps are required to close the vacuum vessels at each end, which include low heat in-leak Cold-to-Warm transitions (CWT) for the beam tubes and 6 kA local electrical feedthrough for powering the quadrupoles. This paper presents the design of the MS SSS cryostats as an extension of the arc cryostat’s design to achieve a standard and consequently cost-effective solution, and the design solutions chosen to satisfy their specific functionalities.

WPAE027 Magnetic Shielding of an Electron Beamline in a Hadron Accelerator Enclosure electron, shielding, dipole, antiproton 1997
  • T.K. Kroc, C.W. Schmidt, A.V. Shemyakin
    Fermilab, Batavia, Illinois
  Funding: *Operated by Universities Research Association Inc. under Contract No. DE-AC02-76CH03000 with the United States Department of Energy.

The Fermilab Electron Cooling Project requires the operation of a 4.35 MeV electron beam in the same enclosure that houses the 120 – 150 GeV Main Injector. Effective shielding of the magnetic fields from the ramped electrical buses and local static fields is necessary to maintain the high beam quality and recirculation efficiency required by the electron cooling system. This paper discusses the operational tolerances and the design of the beamline shielding, bus design, and bus shielding as well as experimental results from the prototype and final installation.

WPAE082 Design of a Precision Positioning System for the Undulators of the Linac Coherent Light Source undulator, alignment, laser, vacuum 4099
  • E. Trakhtenberg, J.T. Collins, P.K. Den Hartog, M. White
    ANL, Argonne, Illinois
  A precision positioning system has been designed for the Linac Coherent Light Source (LCLS) and a prototype system is being fabricated. The LCLS will use a beam based alignment technique to precisely align all of the segments of the 130-m long undulator line. The requirement for overlap between the electron beam and the x-ray beam, in order to develop and maintain lasing, demands that each of the quadrupoles be aligned within a tolerance of ± 2 μm and that the undulator axis be positioned within ± 10 μm vertically and horizontally. Five cam movers, each with an eccentricity of 1.5 mm, will allow adjustment of a cradle supporting the undulator, its vacuum chamber, a quadrupole, and a beam position monitor. An additional motion transverse to the beam axis allows removal of individual undulators from the beam path. Positioning feedback will be provided by a wire position monitor system and a hydrostatic leveling system.  
WPAT081 Ceramic Power Extractor Design at 15.6 GHz dipole, linac, single-bunch, beam-transport 4078
  • A. Smirnov, Y. Luo, R. Yi, D. Yu
    DULY Research Inc., Rancho Palos Verdes, California
  Funding: Work supported by DOE SBIR Grant No. DE-FG03-01ER83232.

Power extractor and coupler designs developed for an experiment planned at the 12th beam harmonic of the upgraded Advanced Wakefield Accelerator (AWA) facility is described. New features are an upstream HOM dielectric damper with additional tapering, and a single-port coupler considered in two variants. Performance analysis includes coupler geometric tolerances, overvoltage, dipole mode wake and BBU; and wakefield losses induced in the damper.

WOAB004 Applying Frequency Map Analysis to the Australian Synchrotron Storage Ring sextupole, resonance, synchrotron, dynamic-aperture 407
  • Y.E. Tan, M.J. Boland, G. LeBlanc
    ASP, Clayton, Victoria
  The technique of frequency map analysis has been applied to study the transverse dynamic aperture of the Australian Synchrotron Storage Ring. The results have been used to set the strengths of sextupoles to optimise the dynamic aperture. The effects of the allowed harmonics in the quadrupoles and dipole edge effects are discussed.  
WOAC001 Aberration Correction in Electron Microscopy electron, sextupole, multipole, acceleration 44
  • H.H. Rose, W. Wan
    LBNL, Berkeley, California
  The resolution of conventional electron microscopes is limited by spherical and chromatic aberrations. Both defects are unavoidable in the case of static rotationally symmetric electromagnetic fields (Scherzer theorem). Multipole correctors and electron mirrros have been designed and built, which compensate for these aberrations. The principles of correction will be demonstrated for the tetrode mirror, the quadrupole-octopole corrector and the hexapole corrector. Electron mirrors require a magnetic beam separator free of second-order aberrations. The multipole correctors are highly symmetric telescopic systems compensating for the defects of the objective lens. The hexapole corrector has the most simple structure yet eliminates only the spherical aberration, whereas the mirror and the quadrupole-octopole corrector are able to correct for both aberrations. Chromatic correction is achieved in the latter corrector by cossed electric and magnetic quadrupoles acting as first-order Wien filters. Micrographs obtained with aberration-corrected electron microscopes will be shown demonstrating the improvement in resolution to better than 1 Angstroem.  
WOAC002 Chromatically Corrected Imaging Systems for Charged-Particle Radiography proton, dipole, sextupole, multipole 225
  • B. Blind, A.J. Jason
    LANL, Los Alamos, New Mexico
  In proton radiography, imaging with systems consisting of quadrupole magnets is an established technique for viewing the material distribution and composition of objects, either statically or during fast events such as explosions. With the most favorable magnet configuration, the –I lens, chromatic aberrations generally dominate the image blur. Image resolution can be improved, and largely decoupled from the input-beam parameters, by using a second-order achromatic bend with some additional higher-order aberration correction. The aberration-correction approach is discussed. For a given resolution, such a bend allows use of much lower-energy imaging particles than a –I lens. Each bend design represents a set of equivalent systems; an 800-MeV proton design and its equivalent 40-MeV electron system are presented. The electron system is useful for imaging small objects. Magnet errors in the achromatic bends must be tightly controlled to preserve image quality, but not beyond feasibility of present technology. System performance is verified by particle tracking. Configurations alternative to the canonical achromatic bend are also discussed.  
WOAC009 Techniques for Measurement and Correction of the SNS Accumulator Ring Optics betatron, SNS, optics, injection 674
  • S. Henderson, P. Chu, S.M. Cousineau, V.V. Danilov, J.A. Holmes, T.A. Pelaia, M.A. Plum
    ORNL, Oak Ridge, Tennessee
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos and Oak Ridge.

The Spallation Neutron Source (SNS) Accumulator Ring will reach peak intensities of 1.5x1014 protons/pulse through multi-turn charge-exchange injection. Accumulation of these unprecedented beam intensities must be accomplished while maintaining extremely low losses (less than 1 W/m). It is anticipated that the control of the ring optics will be important for achieving these low loss rates. We describe our plans for measuring and correcting the optical functions of the accumulator ring lattice.

WOAD005 BEPCII Interaction Region Design and Construction Status vacuum, interaction-region, superconducting-magnet, septum 478
  • Y. Wu, F.S. Chen, X.W. Dai, J.B. Pang, Q.L. Peng, Y. Yang, Z. Yin, C.H. Yu, J.F. Zhang
    IHEP Beijing, Beijing
  • M. Wang
    CAEP/IFP, Mainyang, Sichuan
  BEPC (Beijing Electron Positron Collider) is now upgrading to a double-ring collider with a new and compact interaction region. The multi-purpose superconducting magnets and conventional dual aperture quadrupole magnets are used as final focusing quadrupole in the interaction region .The two beams collide at the interaction point with a cross angle of ±11 mrad and further beams separation is enhanced with the help of a septum bending magnet which locates just beyond the vertically focusing quadrupole and acts on the outgoing beam lines only. This paper will describe the IR design and its construction status.  
RPAE002 Coupling Correction of a Circularly Polarizing Undulator at the Advanced Photon Source coupling, octupole, simulation, undulator 805
  • L. Emery
    ANL, Argonne, Illinois
  Funding: This work is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38.

The electromagnetic Circularly Polarizing Undulator (CPU) installed at the Advanced Photon Source (APS) storage ring produces skew quadrupole field errors, which were initially corrected by a small skew quadrupole magnet at one end of the device. Because the storage ring is operated at 1% coupling or less, a correction not located at the source inside the CPU is insufficient, as we have confirmed in simulation. Adding a skew coil at the other end of the CPU allows us to make a complete correction of the coupling source in the undulator. Correction setpoints are determined by APS's general optimizing software with the vertical beam size of a x-ray pinhole image as a readback.

RPAE003 Optimization and Modeling Studies for Obtaining High Injection Efficiency at the Advanced Photon Source injection, septum, optics, booster 871
  • L. Emery
    ANL, Argonne, Illinois
  Funding: This work is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38.

In recent years, the optics of the Advanced Photon Source storage ring has changed to lower equilibrium emittance (2.5 nm-rad) but at the cost of stronger sextupoles and stronger nonlinearities, which have reduced the injection efficiency from 100% in the high emittance mode. Over the years we have developed a series of optimization, measurement and modeling studies of the injection process, which allows us to obtain or maintain low injection losses. For example, the trajectory in the storage ring is optimized with trajectory knobs for maximum injection efficiency. This can be followed by collecting first-turn trajectory data, from which we can fit the initial phase-space coordinates. The model of the "optimized" trajectory would show whether the beam comes too close to a physical aperture in the injection magnets. Another modeling step is the fit and correction of the transfer line optics, which has a significant impact on phase-space matching.

RPAE006 Feasibility Study on Introducing a Superconducting Wiggler to Saga Light Source lattice, dynamic-aperture, multipole, wiggler 1021
  • S. Koda, Y. Iwasaki, T. Okajima, H. Setoyama, Y. Takabayashi, T. Tomimasu, K. Yoshida
    Saga Synchrotron Light Source, Industry Promotion Division, Saga City
  • H. Ohgaki
    Kyoto IAE, Kyoto
  • M. Torikoshi
    NIRS, Chiba-shi
  Saga light source (SAGA-LS) is the synchrotron radiation facility, which consists of 250 MeV electron linac and 1.4 GeV storage ring. We have a plan to introduce an existing superconducting wiggler, which has been developed for other project by National Institute of Radiological Sciences. The superconducting wiggler consists of a main pole of 7T and two side poles of 4T. Each pole is composed of a racetrack-shaped coil and an iron core. We have examined the effects of the wiggler on the beam optics when it is introduced into SAGA-LS. The distribution of multipole components in the planes perpendicular to the electron orbit, which is deformed by the wiggler fields, have been calculated using magnetic field calculation code RADIA. Then the lattice function and the dynamic aperture of the ring have been calculated by the lattice calculation code SAD. The results show that the tune shift due to the quadrupole component of the wiggler field is as large as to make horizontal beam orbit unstable. The dynamic aperture after the tune correction becomes small by about 20%. These effects due to multipole field are considered to be tolerable for the SAGA-LS.  
RPAE028 Lattice Upgrade Options for the ESRF Storage Ring emittance, dipole, lattice, optics 2047
  • Y. Papaphilippou, P. Elleaume, L. Farvacque, A. Ropert
    ESRF, Grenoble
  Several scenarios of lattice upgrade for the ESRF storage ring are under study. In order to minimise the cost, their design is based on the length constraints of the existing tunnel with the ID beamlines kept in place. The goal is to shrink the emittance in order to increase the undulator brilliance. The two main options are a double bend achromat structure with non-uniform field dipoles and a triple bend achromat lattice. The two scenarios are detailed and compared with respect to their linear optics solutions, correction of chromatic effects and non-linear dynamics. An attempt to reveal the horizontal effective emittance dependence on important design parameters, such as optics functions maxima, chromaticity and dynamic aperture, is also undertaken. Technological challenges concerning magnet design with small physical aperture in a reduced space are also addressed.  
RPAE030 Status of the SOLEIL Booster Synchrotron booster, power-supply, dipole, injection 2155
  • A. Loulergue
    SOLEIL, Gif-sur-Yvette
  Funding: SOLEIL.

SOLEIL is a 2.75 GeV third generation synchrotron radiation facility under construction near Paris. The injection system is composed of a 100 MeV electron Linac pre-accelerator followed by a full energy (2.75 GeV) booster synchrotron. The booster lattice is based on a FODO structure with missing magnet. With a circumference of 157 m and low field magnets (0.74 T), the emittance is of 150 nm.rad at 2.75 GeV. A flexible and economic ramping switched mode procedure for the main supply cycled up to 3 Hz and a 35 kW-352 MHz solid state amplifier powering the RF system are used. At present time, all the magnets, supports and vacuum have been received and tested. Half of the ring is already assembled and installation is the tunnel will begin in January 05. The pulsed elements and their pulser will be received and tested from January to April. The four main magnet power supplies will be received in February and tested in Marsh. We plan the booster commissioning with beam in May 2005.

RPAE031 Progress Report on the Construction of SOLEIL vacuum, sextupole, power-supply, dipole 2203
  • M.-P. Level, J.C. Besson, P. Brunelle, R. Chaput, A. Dael, J.-C. Denard, J.-M. Filhol, J.M. Godefroy, C. Herbeaux, V. Le Roux, P. Marchand, A. Nadji, L.S.N. Nadolski, R. Nagaoka, M.-A. Tordeux
    SOLEIL, Gif-sur-Yvette
  Funding: SOLEIL

This paper reports the progress achieved in the construction of the accelerators of SOLEIL. Started in January 2002, the construction comes near to its end and the installation of the equipment on the site has begun from September 2004 and shall be completed within one year. The progress on the LINAC and Booster are reported separately, therefore this paper will focus more particularly on the Storage Ring: Dedicated measuring benches have been built to perform the magnetic measurements on all the magnets and the results of measurements have been analysed in term of particle dynamics behaviour in order to prepare the operating point for the commissioning. The status of innovative developments engaged from the beginning as super-conducting RF cavities, NEG coated vacuum chambers and BPMs digital electronics will be described. The construction of the first 6 insertion devices is also well advanced and will be reported. Finally, the machine impedance budget was further evaluated with consequently, still some modifications to the design of some components.

RPAE041 Reconstruction of Photon Factory Storage Ring for the Straight-Sections Upgrade Project emittance, undulator, factory, photon 2678
  • T. Honda, S. Asaoka, W.X. Cheng, K. Haga, K. Harada, Y. Hori, M. Izawa, T. Kasuga, Y. Kobayashi, H. Maezawa, A. Mishina, T. Mitsuhashi, T. Miyajima, H. Miyauchi, S. Nagahashi, T. Nogami, T. Obina, C.O. Pak, S. Sakanaka, Y. Sato, T. Shioya, M. Tadano, T. Takahashi, Y. Tanimoto, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, S. Yamamoto
    KEK, Ibaraki
  The Photon Factory (PF) storage ring is a 2.5-GeV synchrotron light source at KEK. In 1997, we have accomplished a large reconstruction of the ring in order to reduce the beam emittance from 130 nm rad to 36 nm rad. After the reconstruction, the PF ring has continued a stable operation over 5000 hours a year. Now we are proceeding with another upgrade project to create four new straight sections and to largely lengthen the existing 10 straight sections. The shutdown for the upgrade project is scheduled for the period March-September 2005. The lattice configuration around the straight sections will be modified by replacing quadrupole magnets with new shorter ones and by placing them closer to the near-by bending magnets. Simultaneously the beam duct in two thirds of the storage ring will be replaced. Due to this modification of the lattice, the practical emittance will be reduced to 27 nm rad. The new straight sections will have low beta functions and suitable for housing short-period narrow-gap undulators. The in-vacuum undulators, which have a sufficiently high brilliance within a spectral range from 8 to 16 keV, are being developed now.  
RPAE049 Revision of Booster to Storage Ring Transport Line Design and Injection Scheme for Top-Up Operation at NSRRC kicker, injection, booster, extraction 3085
  • M.-H. Wang, H.-P. Chang, J. Chen, J.-R. Chen, K.-T. Hsu, C.-C. Kuo, G.-H. Luo
    NSRRC, Hsinchu
  In order to help the operation of constant current, the optics of booster to storage ring transport line (BTS) design is reinvestigated. The initial twiss parameters are derived by measurement. The optics of the transport line is readjusted according to the measured initial beam parameters. The design of pulse width of the injection kicker is also changed from 1.2μsecond to 2.0μsecond. The injection scheme is reviewed and the effects of the kicker error on both injected beam and stored beam are investigated and shown in this report.  
RPAE050 Status of the CAMD Light Source lattice, wiggler, emittance, diagnostics 3103
  • V.P. Suller
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • E.J. Anzalone, M.G. Fedurin, P. Jines, D.J. Launey, T.A. Miller, Y. Wang
    LSU/CAMD, Baton Rouge, Louisiana
  With the increasing diversity of its research program, the CAMD Light Source has improved its beam brightness and quality. Using a well calibrated model of the lattice, the ring optic has been refined to generate a lower beam emittance of 150 nm.rad and this has been confirmed by measuring the beta values with the modulated quadrupole shunt system. The beam sizes have also been measured with an X-ray pinhole camera and compared to the calculated emittance. The beam orbit is corrected to a standard position referenced to the quadrupole centers to a precision better than 0.5 mm, using a suite of well localized bumps which can also flexibly steer the user photon beams to their requirements. Beam reliability has been improved by bringing into use a VME control system for the energy ramp.  
RPAE051 Multipole Design for CAMD Storage Ring multipole, sextupole, power-supply, storage-ring 3161
  • V.P. Suller
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • M.G. Fedurin, P. Jines, T.A. Miller
    LSU/CAMD, Baton Rouge, Louisiana
  The CAMD storage ring has been in operation more than 12 years with only sextupole elements in the lattice for correction of nonlinear beam dynamics. To compensate for coupling arising from the integrated effect of skewed elements around the ring, and to improve beam lifetime, a multipole element is required which can be operated in active mode. The design of a magnetic multipole is presented as well as power and control systems designs. The strength and effect and of this element are calculated.  
RPAE057 Dynamic Aperture Optimization for Low Emittance Light Sources lattice, sextupole, emittance, dipole 3378
  • S.L. Kramer, J. Bengtsson
    BNL, Upton, Long Island, New York
  Funding: Under Contract with the United States Department of Energy Contract Number DE-AC02-98CH10886.

State of the art low emittance light source lattices, require small bend angle dipole magnets and strong quadrupoles. This in turn creates large chromaticity and small value of dispersion in the lattice. To counter the high chromaticity strong sextupoles are required which limit the dynamic aperture. Traditional methods for expanding the dynamic aperture use harmonic sextupoles to counter the tune shift with amplitude. This has been successful up to now, but is non-deterministic and limited as the sextupole strength increases, driving higher order nonlinearities. We have taken a different approach that makes use of the tune flexibility of a TBA lattice to minimize the lowest order nonlinearities, freeing the harmonic sextupoles to counter the higher order nonlinearities. This procedure is being used to improve the nonlinear dynamics of the NSLS-II lattice.

RPAE062 Estimation of the Effective Magnet Misalignments of the ALS Storage Ring lattice, storage-ring, closed-orbit, coupling 3559
  • H. Nishimura, T. Scarvie
    LBNL, Berkeley, California
  Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC03-76SF00098

New storage ring lattices have traditionally been commissioned using a trial-and-error approach, where the number of turns circulated is slowly built up until enough beam is stored to correct the orbit. We have found that by combining the calculated response matrix of magnet misalignments from a linear model of a new lattice with the measured steering magnet response matrix used during normal operations, it is possible to make an educated guess for the steering magnet settings that will immediately allow beam circulation in the new lattice. “Effective” magnet misalignments are simply those that are sufficiently close to the real misalignments to make the first guess good enough to circulate beam; the relationship between effective and real magnet misalignments is also discussed in the paper. This predictive steering method makes the process of establishing enough circulating beam for SVD-based orbit correction in a new lattice very efficient.

RPAE087 Progress of the Synchrotron Light Source ALBA lattice, storage-ring, synchrotron, vacuum 4203
  • D. Einfeld, E. Al-Dmour, J. Campmany, M. Muñoz, M. Pont, F. Pérez
    CELLS, Bellaterra (Cerdanyola del Vallès)
  ALBA will be a third generation synchrotron light source built in Spain near Barcelona. Commissioning of the storage ring is foreseen to start at the end of 2008. The design phase of ALBA is almost completed and the first components are ready to be ordered. A 100 MeV LINAC will inject electrons into a nominal energy booster synchrotron of similar circumference as the storage ring, so that both accelerators will share the same tunnel. The storage ring, working at 3 GeV with a circumference of 268.8 m, has been designed for a maximum current of 400 mA. The lattice is based on an extended DBA structure and has a nominal emittance of 4 nm.rad.The machine has a four fold symmetry with 4 long straight sections (8 m), 12 medium (4.2 m) and 8 short (2.6 m). This report concentrates on recent design developments, component choices and current status. Another paper at this conference deals with accelerator physics issues.  
RPAP011 Technical Development of Profile Measurement for the Soft X-Ray Via Compton Backward Scattering electron, laser, scattering, background 1260
  • T. Saito, Y. Hama, K. Hidume, S. Minamiguchi, A. Oshima, D. Ueyama, M. Washio
    RISE, Tokyo
  • H. Hayano, J.U. Urakawa
    KEK, Ibaraki
  • S. Kashiwagi
    ISIR, Osaka
  • R. Kuroda
    AIST, Tsukuba, Ibaraki
  A compact X-ray source is called for such various fields as material development, biological science, and medical treatment. At Waseda University, we have already succeeded to generate the soft X-ray of the wavelength within so-called water window region (250-500eV) via Compton backward scattering between 1047nm Nd:YLF laser and 4.2MeV high quality electron beam. Although this method equips some useful characters, e.g. high intensity, short pulse, energy variableness, etc, the X-ray generating system is compact enough to fit in tabletop size. In the next step, there rises two principal tasks, that is, to make the soft X-ray intensity higher, and to progress X-ray profile measurement techniques as preliminary experiments for biomicroscopy. Specifically, we utilize two-pass amp for the former, and irradiate X-ray to a resist film which is previously exposed by UV lamp or get images with X-ray CCD for the latter. In this conference, we will show the experimental results and some future plans.  
RPAP021 A Portable Electron Radiography System electron, proton, collimation, permanent-magnet 1715
  • F.E. Merrill, C.L. Morris
    LANL, Los Alamos, New Mexico
  • K. Folkman, F. Harmon, A.W. Hunt, B. King
    ISU, Pocatello, Idaho
  The technique of charged particle radiography has been developed and proven with 800 MeV protons at LANSCE and 24 GeV protons at the AGS. Recent work at Los Alamos National Laboratory in collaboration with the Idaho Accelerator Center has extended this diagnostic technique to electron radiography through the development of an inexpensive and portable electron radiography system. This system has been designed to use 30 MeV electrons to radiograph thin static and dynamic systems. The system consists of a compact 30 MeV pulsed electron linear accelerator coupled to a quadrupole lens magnifier constructed from permanent magnet quadrupoles. The design features and operational characteristics of this radiography system are presented as well as the radiographic performance parameters.  
RPAP032 Hardware Tracking Related to Compact Medical Pulse Synchrotron dipole, synchrotron, proton, acceleration 2260
  • K. Endo, K. Egawa, Z. Fang
    KEK, Ibaraki
  • S. Yamanaka
    NIRS, Chiba-shi
  A compact 200 MeV proton synchrotron for the radiotherapy is being developed. Dipole and quadrupole magnets were already manufactured and are ready to measure their field properties under the pulse excitation. Preliminary field measurement was already done on the prototype dipole. Small RF cavity with a wide bandwidth (2~18 MHz) was successfully developed. Concerning to the simultaneous pulse operation of these components, there are some issues to be solved beforehand. These are the tracking between dipole field and the quadruple field gradient, the RF frequency generation sensing the dipole current (or field), the sextupole field correction of the dipole and etc. These issues studied experimentally using the dipole current will be presented in conjunction with the progress of the development.  
RPAP043 Beam-Based Alignment in the RHIC eCooling Solenoids ion, alignment, electron, proton 2771
  • P. Cameron, I. Ben-Zvi, W.C. Dawson, J. Kewisch, V. Litvinenko, Y. Luo, W.W. MacKay, C. Montag, J. Niedziela, V. Ptitsyn, T. Satogata, C. Schultheiss, V. Yakimenko
    BNL, Upton, Long Island, New York
  Funding: U.S. DOE.

Accurate alignment of the electron and ion beams in the RHIC electron cooling solenoids is crucial for well-optimized cooling. Because of the greatly differing rigidities of the electron and ion beams, to achieve the specified alignment accuracy it is required that transverse magnetic fields resulting from imperfections in solenoid fabrication be down by five orders of magnitude relative to the pure solenoid fields. Shimming the solenoid field to this accuracy might be accomplished by survey techniques prior to operation with beam, or by methods of beam-based alignment. We report on the details of a method of beam-based alignment, as well as the results of preliminary measurements with the ion beam at RHIC

RPAT028 RHIC BPM System Modifications and Performance injection, alignment, radiation, instrumentation 2021
  • T. Satogata, R. Calaga, P. Cameron, P. Cerniglia, J. Cupolo, A.J. Curcio, W.C. Dawson, C. Degen, J. Gullotta, J. Mead, R.J. Michnoff, T. Russo, R. Sikora
    BNL, Upton, Long Island, New York
  Funding: Work performed under the auspices of the U.S. Department of Energy.

The RHIC beam position monitor (BPM) system provides independent average orbit and turn-by-turn (TBT) position measurements. In each ring, there are 162 measurement locations per plane (horizontal and vertical) for a total of 648 BPM planes in the RHIC machine. During 2003 and 2004 shutdowns, BPM processing electronics were moved from the RHIC tunnel to controls alcoves to reduce radiation impact, and the analog signal paths of several dozen modules were modified to eliminate gain-switching relays and improve signal stability. This paper presents results of improved system performance, including stability for interaction region and sextupole beam-based alignment efforts. We also summarize performance of improved million-turn TBT acquisition channels for nonlinear dynamics and echo studies.

RPAT033 Beta Function Measurement in the Tevatron Using Quadrupole Gradient Modulation coupling, lattice, emittance, dipole 2272
  • A. Jansson, P. Lebrun, J.T. Volk
    Fermilab, Batavia, Illinois
  Funding: Work supported by the U.S. Department of Energy.

Early in Run2, there was an effort to compare the different emittance measurements in the Tevatron (flying wires and synchtotron light) and understand the origin of the observed differences. To measure the beta function at a few key locations near the instruments, air-core quadrupoles were installed. By modulating the gradient of these magents and measuring the effect on the tune, the lattice parameters can be extracted. Initially, the results seem to disagree with with other methods. At the time, the lattice was strongly coupled due to a skew component in the main dipoles, caused by sagging of the cryostat. After a large fraction of the superconducting magnets were shimmed to remove a strong skew quadrupole component, the results now agree with expectations, confirming that the beta function is not the major error source of discrepancy in the emittance measurement.

RPAT038 Diagnostic for Electron Clouds Trapped in Quadrupoles electron, simulation, diagnostics, proton 2547
  • R.J. Macek, A. A. Browman
    TechSource, Santa Fe, New Mexico
  Funding: Work supported by a DOE SBIR Phase I grant DE-FG02-04ER84105.

Simulations have indicated that electron clouds generated by beam-induced multipactor can be trapped in the mirror-like fields of magnetic quadrupoles and thereby contribute significantly to the electron cloud buildup in high intensity accelerators and storage rings. This could be the most important source of electrons driving the two-stream (e-p) instability at the Los Alamos PSR and may also play a significant role in electron cloud effects at some of the new high intensity accelerator projects. We will describe the physics design and optimization of an electron-sweeping detector designed to measure the trapped electrons at various times after the beam pulse has passed. The instrument can also serve as an electro-magnetically shielded detector providing a signal obtained from electrons striking the wall during the passage of beam bunches.

RPAT043 Developments of the Calibration Tools for Beam Position Monitor at J-PARC Linac linac, beam-losses, proton, beam-transport 2777
  • S. Sato, H. Akikawa, T. Tomisawa, A. Ueno
    JAERI/LINAC, Ibaraki-ken
  • Z. Igarashi, M. Ikegami, N. Kamikubota, S. Lee, T. Toyama
    KEK, Ibaraki
  In the J-PARC LINAC, there are mainly two requirements for the beam based calibration of beam position monitors (BPMs). One is that BPMs need to be calibrated with the accuracy of about a hundred micro-meters to minimize beam loss for the world highest class of proton intensity. The other is that about a hundred of BPMs need to be calibrated consistently. To achieve these requirements, the calibration tool are being developed with experiences on real beam in a MEBT line set for the DTL commissioning. Tools for simulating the beam trajectory using transport matrix (e.g. T3D) are being developed as well. The calibrated beam positions measured by BPMs are used in the simulation for tuning the beam. Implementation of the calibration tools on the same platform (e.g. SAD) with the simulation tools is important for higher usability during commissioning of whole J-PARC. In this paper, details of these developments around BPMs are to be reported.  
RPAT096 High-Precision Resonant Cavity Beam Position, Emittance and Third-Moment Monitors dipole, coupling, impedance, sextupole 4311
  • N. Barov, J.S. Kim, A.W. Weidemann
    Far-Tech, Inc., San Diego, California
  • R.H. Miller, C.D. Nantista
    SLAC, Menlo Park, California
  Funding: Work supported by the U.S. Dept. of Energy.

Linear colliders and FEL facilities need fast, nondestructive beam position and profile monitors to facilitate machine tune-up, and for use with feedback control. FAR-TECH, Inc. is developing a resonant cavity diagnostic to simultaneously measure the dipole, quadrupole and sextupole moments of the beam distribution. Measurements of dipole and quadrupole moments at multiple locations yield information about beam orbit and emittance. The sextupole moment can reveal information about beam asymmetry which is useful in diagnosing beam tail deflections caused by short range dipole wakefields. In addition to the resonance enhancement of a single-cell cavity, use of a multi-cell standign-wave structure further enhances signal strength and improves the resolution of the device. An estimated rms beam size resolution is sub micro-meters and beam position is sub nano-meter.

ROAD005 Status of NEG Coating at ESRF vacuum, insertion, insertion-device, storage-ring 422
  • M. Hahn
    ESRF, Grenoble
  • R. Kersevan
    ORNL, Oak Ridge, Tennessee
  The ESRF non-evaporable getter (NEG) coating facility is in operation since two years now. A large part of the insertion device straight sections of the electron storage ring has been equipped with in-house coated 5m long aluminum vacuum chambers with an inner vertical aperture of 8 mm. Operational experience with different coating parameters leading to different film thicknesses will be given and compared to bremsstrahlung data. The paper deals also with improvements of the coating production and chamber preparation, and describes some aspects of NEG coating data acquisition, visualization, and remote control. The R&D program leading to a more powerful DC solenoidal coating tool to further improve the NEG coating production throughput and quality aspects is also discussed.  
ROPB002 Experiments Studying Desorbed Gas and Electron Clouds in Ion Accelerators electron, ion, diagnostics, simulation 194
  • A.W. Molvik, J.J. Barnard, R.H. Cohen, A. Friedman, M. Kireeff Covo, S.M. Lund
    LLNL, Livermore, California
  • D. Baca, F.M. Bieniosek, C.M. Celata, P.A. Seidl, J.-L. Vay, W. Waldron
    LBNL, Berkeley, California
  • J.L. Vujic
    UCB, Berkeley, California
  Funding: This work was performed under the auspices of the U.S. Department of Energy by University of California, LLNL under contract No. W-7405-Eng-48, and by LBNL under Contract DE-AC03-76F00098.

Electron clouds and gas pressure rise limit the performance of many major accelerator rings. We are studying these issues experimentally with ~1 MeV heavy-ion beams, coordinated with significant efforts in self-consistent simulation and theory.* The experiments use multiple diagnostics, within and between quadrupole magnets, to measure the sources and accumulation of electrons and gas. In support of these studies, we have measured gas desorption and electron emission coefficients for potassium ions impinging on stainless steel targets at angles near grazing incidence.** Our goal is to measure the electron particle balance for each source – ionization of gas, emission from beam tubes, and emission from an end wall – determine the electron effects on the ion beam and apply the increased understanding to mitigation.

*J-L. Vay, Invited paper, session TICP; R. H. Cohen et al., PRST-AB 7, 124201 (2004). **M. Kireeff Covo, this conference; A. W. Molvik et al., PRST-AB 7, 093202 (2004).

ROPB003 Electron Cloud Dynamics in High-Intensity Rings electron, SNS, dipole, space-charge 245
  • L. Wang, J. Wei
    BNL, Upton, Long Island, New York
  Funding: Work performed under the auspices of the U.S. Department of Energy. SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.

Electron cloud due to beam induced multipacting is one of the main concerns for the high intensity rings because the electron multipacting becomes stronger with the increment of beam intensity. Electrons generated and accumulated inside the beam pipe form an "electron cloud" that interacts with the circulating charged particle beam. With sizeable amount of electrons, this interaction can cause beam instability, beam loss and emittance growth. At the same time, the vacuum pressure will rise due to electron desorption. This talk intends to provide an overview of the dynamics of the typical electron multipacting in various magnetic fields and mitigation measures in both long bunch and short bunch rings.

ROPB006 Filling in the Roadmap for Self-Consistent Electron Cloud and Gas Modeling electron, ion, simulation, heavy-ion 525
  • J.-L. Vay, M.A. Furman, P.A. Seidl
    LBNL, Berkeley, California
  • R.H. Cohen, K. Covo, A. Friedman, D.P. Grote, A.W. Molvik
    LLNL, Livermore, California
  • P. Stoltz, S.A. Veitzer
    Tech-X, Boulder, Colorado
  • J. Verboncoeur
    UCB, Berkeley, California
  Funding: This work was performed under the auspices of the U.S. Department of Energy by University of California, LLNL and LBNL under contracts W-7405-Eng-48, and DE-AC03-76F00098.

Electron clouds and gas pressure rise limit the performance of many major accelerators. A multi-laboratory effort to understand the underlying physics via the combined application of experiment,* theory, and simulation is underway. We present here the status of the simulation capability development, based on a merge of the three-dimensional parallel Particle-In-Cell accelerator code WARP and the electron cloud code POSINST, with additional functionalities.** The development of the new capability follows a "roadmap" describing the different functional modules, and their inter-relationships, that are ultimately needed to reach self-consistency. Newly developed functionalities include a novel particle mover bridging the time scales between electrons and ions motion.*** Samples of applications of the new capability to the modeling of intense charge dominated beams**** and LHC beams***** will be shown as available.

*A.W. Molvik, these proceedings. **J.-L. Vay, Proc. "ECLOUD04," Napa (California), 2004. ***R.H. Cohen, these proceedings. ****P.A. Seidl, these proceedings. *****M.A. Furman, these proceedings.

RPPE008 Water Induced Vibration in the NSRRC damping, storage-ring, vacuum, coupling 1102
  • D.-J. Wang, H.C. Ho, Z.-D. Tsai, J. Wang
    NSRRC, Hsinchu
  Water flow related vibrations were found on the spectrum of electron beam position monitor in the NSRRC. They were associated with the vibrations of quadrupole magnets. One major vibration source was from a pump in the cooling water system. Most amount of vibration coupled through water pipe and water flow and propagated to the magnets. A small water flow station was set up to study the effect about coupling, propagating and excitation. Some damping schemes tested in the ring to improve the vibration are also included..  
RPPE039 Alumina Ceramics Vacuum Duct for the 3GeV-RCS of the J-PARC impedance, vacuum, dipole, electron 2604
  • M. Kinsho
    Japan Atomic Energy Institute, Linac Laboratory, Tokai-Mura
  • Z. Kabeya
    MHI, Nagoya
  • N. Ogiwara
    JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • Y. Saito
    KEK, Ibaraki
  It was success to develop alumina ceramics vacuum ducts for the 3GeV-RCS of J-PARC at JAERI. There are two types of alumina ceramics vacuum ducts needed, one being 1.5m-long duct with a circular cross section for use in the quadrupole magnet, the other being 3.5m-long and bending 15 degrees, with a race-track cross section for use in the dipole magnet. These ducts could be manufactured by joining several duct segments of 0.5-0.8 m in length by brazing. The alumina ceramics ducts have copper stripes on the outside surface of the ducts to reduce the duct impedance. One of the ends of each stripe is connected to a titanium flange by way of a capacitor so to interrupt an eddy current circuit. The copper stripes are produced by an electroforming method in which a stripe pattern formed by Mo-Mn metallization is first sintered on the exterior surface and then overlaid by PR-electroformed copper (Periodic current Reversal electroforming method). In order to reduce emission of secondary electrons when protons or electrons strike the surface, TiN film is coated on the inside surface of the ducts.  
RPPE046 A Summary and Status of the SNS Ring Vacuum Systems vacuum, injection, dipole, target 2929
  • M. Mapes, H.-C. Hseuh, J. Rank, L. Smart, R.J. Todd, D. Weiss
    BNL, Upton, Long Island, New York
  • M.P. Hechler, P. Ladd
    ORNL, Oak Ridge, Tennessee
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos, and Oak Ridge.

The Spallation Neutron Source (SNS) ring is designed to accumulate high intensity protons. The SNS ring vacuum system consists of the High Energy Beam Transport (HEBT) line, Accumulator Ring and the Ring to Target Beam Transport (RTBT) line. The Accumulator ring has a circumference of 248m with 4 arcs and 4 straight sections, while the RTBT and HEBT have a total length of 350m of beam transport line. Ultrahigh vacuum of 10-9 Torr is required in the accumulator ring to minimize beam-residual gas ionization. To reduce the secondary electron yield (SEY) and the associated electron cloud instability, the ring vacuum chambers are coated with Titanium-Nitride (TiN). This paper describes the design, fabrication, assembly and vacuum processing of the ring and beam transport vacuum systems as well as the associated instrumentation and controls.

RPPE076 Overview of Electrical Systems for the University of Maryland Electron Ring (UMER) dipole, injection, electron, cathode 3988
  • B. Quinn, G. Bai, S. Bernal, T.F. Godlove, I. Haber, J.R. Harris, M. Holloway, H. Li, J.G. Neumann, P.G. O'Shea, K. Tian, M. Walter
    IREAP, College Park, Maryland
  • M. Reiser
    University Maryland, College Park, Maryland
  Funding: This work is funded by the United States Department of Energy under grants DE-FG02-94ER40855 and DE-FG02-92ER54178.

Commissioning of the University of Maryland Electron Ring (UMER) is underway (see general abstract on UMER). We discuss the various electrical systems of UMER. The power system includes 114 supplies for 70 air-core magnetic quadrupoles, 36 bending dipoles and 30+ steering dipoles as well as earth's field compensating coils. Systems for data collection comprise multiplexers and fast digitizers for diagnostics including 15 fast beam position monitors (BPMs)and video capture from fluorescent screen monitors. Several pulsers have been built in-house for injection and extraction magnets. The stringent timing schemes are also presented.

RPPP001 Commissioning and First Measurements on the CTF3 Chicane linac, emittance, vacuum, background 785
  • A. Ghigo, D. Alesini, G. Benedetti, C. Biscari, M. Castellano, A. Drago, D. Filippetto, F. Marcellini, C. Milardi, B. Preger, M. Serio, F. Sgamma, A. Stella, M. Zobov
    INFN/LNF, Frascati (Roma)
  • R. Corsini, T. Lefevre, F. Tecker
    CERN, Geneva
  The transfer line between the linac and the first recombination ring (Delay Loop) of the CTF3 project hs been installed at CERN in spring-summer 2004. In the transfer line a magnetic chicane is used to tune the length of the bunches coming from the linac in order to minimize the Coherent Synchrotron Radiation contribution to the beam energy spread in the recombination system. The first measurements of the beam parameters at several linac and stretcher settings are described. We report the compression curve as a function of the optical parameter R56 representing the dependence of the longitudinal position of a particle on its energy, obtained by measuring the bunch length with a 3 GHz RF deflector.  
RPPP009 Luminosity Tuning Bumps in the CLIC Main Linac luminosity, emittance, simulation, linac 1141
  • P. Eliasson, P. Eliasson
    Uppsala University, Uppsala
  • D. Schulte
    CERN, Geneva
  Funding: We acknowledge the support of the European Community-Research Infrastructure Activity under the FP6 "Structuring the European Research Area" programme (CARE, contract number RII3-CT-2003-506395).

Preservation of beam emittance in the CLIC main linac is a challenging task. This requires not only beam-based alignment of the beam line components but also the use of emittance tuning bumps. In this paper the potential use of luminosity tuning bumps is explored and compared to emittance tuning bumps.

RPPP010 Considerations on the Design of the Decelerator of the CLIC Test Facility (CTF3) simulation, damping, linac, beam-losses 1177
  • D. Schulte, I. Syratchev
    CERN, Geneva
  Funding: We acknowledge the support of the European Community-Research Infrastructure Activity under the FP6 "Structuring the European Research Area" programme (CARE, contract number RII3-CT-2003-506395).

One of the main aims of the CLIC Test Facility (CTF3) is to study the beam stability in the drive beam decelerator and to bench mark the performance against beam simulation codes. Particular challenges come from the large drive beam energy spread, the strong wakefields and potential beam losses. The development towards a decelerator design and the required instrumentation is described in this paper.

RPPP011 Different Options for Dispersion Free Steering in the CLIC Main Linac linac, emittance, electron, positron 1251
  • D. Schulte
    CERN, Geneva
  Funding: We acknowledge the support of the European Community-Research Infrastructure Activity under the FP6 "Structuring the European Research Area" programme (CARE, contract number RII3-CT-2003-506395).

Sophisticated beam-based alignment is essential in future linear colliders to preserve the beam emittance during the transport through the main linac. One such method is dispersion free steering. In this paper different options to implement this method are discussed, based on the use of different accelerating gradients, RF phases and bunch particle types during a beam pulse.

RPPP017 Compact Superconducting Final Focus Magnet Options for the ILC extraction, superconducting-magnet, septum, feedback 1569
  • B. Parker, M. Anerella, J. Escallier, M. Harrison, P. He, A.K. Jain, A. Marone, K.-C. Wu
    BNL, Upton, Long Island, New York
  • T.W. Markiewicz, T.V.M. Maruyama, Y. Nosochkov, A. Seryi
    SLAC, Menlo Park, California
  Funding: Work supported by the U.S. Department of Energy under contracts DE-AC-02-98-CH10886 and DE-AC02-76SF00515.

We present a compact superconducting final focus (FF) magnet system for the ILC based on recent BNL direct wind technology developments. Direct wind gives an integrated coil prestress solution for small transverse size coils. With beam crossing angles more than 15 mr, disrupted beam from the IP passes outside the coil while incoming beam is strongly focused. A superconducting FF magnet is adjustable to accommodate collision energy changes, i.e. energy scans and low energy calibration runs. A separate extraction line permits optimization of post IP beam diagnostics. Direct wind construction allows adding separate coils of arbitrary multipolarity (such as sextupole coils for local chromaticity correction). In our simplest coil geometry extracted beam sees significant fringe field. Since the fringe field affects the extracted beam, we also study advanced configurations that give either dramatic fringe field reduction (especially critical for gamma-gamma colliders) or useful quadrupole focusing on the outgoing beam channel. We present prototype coil winding test results and discuss our progress toward an integrated FF solution that addresses important machine detector interface issues.

RPPP023 A Compact Damping Ring Using RF Deflectors for the International Linear Collider damping, kicker, dynamic-aperture, extraction 1811
  • R.W. Helms, D. L. Rubin
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  Funding: NSF

Current specifications for the International Linear Collider call for bunch trains hundreds of kilometers in length. We describe a scheme for manipulating a compressed bunch train in the damping ring using RF deflectors and multiple transfer lines. The concept is demonstrated in the design of a 4 km damping ring that circulates 2800 bunches spaced 4 ns apart, and we show that injection and extraction of individual bunches is possible with conventional kickers requiring rise/fall times of only 16 ns. The performance and stability of the 4 km damping ring is evaluated and compared with existing machines.

RPPP024 Comparison of Beam-Based Alignment Algorithms for the ILC emittance, alignment, linac, shielding 1847
  • J.C. Smith, L. Gibbons, J.R. Patterson, D. L. Rubin
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  • D. Sagan
    Cornell University, Department of Physics, Ithaca, New York
  • P. Tenenbaum
    SLAC, Menlo Park, California
  Funding: NSF and DOE.

The International Linear Collider (ILC) alignment tolerances require more sophisticated alignment techniques than those provided by survey alone. Various Beam-Based Alignment algorithms have been proposed to achieve the desired low emittance preservation. These algorithms are compared and their merits identified using the TAO accelerator simulation program.

RPPT020 Space Charge Effects for the ERL Prototype Injector Line at Daresbury Laboratory emittance, space-charge, dipole, linac 1676
  • B.D. Muratori, H.L. Owen
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • C. Gerth
    DESY, Hamburg
  • M.J. de Loos, S.B. van der Geer
    PP, Soest
  Daresbury Laboratory is currently building an Energy Recovery Linac Prototype (ERLP) that will operate at a beam energy of 35 MeV. In this paper we examine the space charge effects on the beam dynamics in the ERLP injector line. A Gaussian particle distribution is tracked with GPT (General Particle Tracer) through the injection line to the main linac to calculate the effect of 3Dspace charge in the dipoles. The nominal beam energy in the injection line is 8.3 MeV and the bunch charge 80 pC. The effects of space charge on the transverse and longitudinal emittance are studied for various electron beam parameter settings.  
RPPT049 Linear Optics Compensation of the Superconducting Wiggler in HLS wiggler, storage-ring, optics, focusing 3037
  • L. Wang, G. Feng, W. Li, H. Xu, H. Zhang
    USTC/NSRL, Hefei, Anhui
  Hefei Light Source is a dedicated VUV light source. A superconducting wiggler magnet with 6 Tesla magnetic field was installed on the storage ring to generate hard X-ray radiation. With the compensation of tune shift due to insertion device, beam was successfully stored, but the beam lifetime was decreased much. In order to cure the lifetime, a simple hard-edge model of the wiggler was constructed in lattice simulation code and the compensation scheme was extensively studied again. Calculation showed that it is difficulty to localize the strong focusing effects from wiggler magnet. Then, a new scheme was brought forward and experimental result showed that it can restore the beam lifetime largely. As the application of LOCO method in HLS, a new compensation scheme was calculated by response matrix fitting, and the experimental result also presented in this paper.  
RPPT051 Electron Model of Linear-Field FFAG acceleration, resonance, electron, extraction 3173
  • S.R. Koscielniak
    TRIUMF, Vancouver
  • C. Johnstone
    Fermilab, Batavia, Illinois
  Funding: TRIUMF receives federal funding via a contribution agreement through the National Research Council of Canada.

A fixed-field alternating-gradient accelerator (FFAG) that employs only linear-field elements ushers in a new regime in accelerator design and dynamics. The linear-field machine has the ability to compact an unprecedented range in momenta within a small component aperture. With a tune variation which results from the natural chromaticity, the beam crosses many strong, uncorrec-table, betatron resonances during acceleration. Further, relativistic particles in this machine exhibit a quasi-parabolic time-of-flight that cannot be addressed with a fixed-frequency rf system. This leads to a new concept of bucketless acceleration within a rotation manifold. With a large energy jump per cell, there is possibly strong synchro-betatron coupling. A few-MeV electron model has been proposed to demonstrate the feasibility of these untested acceleration features and to investigate them at length under a wide range of operating conditions. This paper presents a lattice optimized for a 1.3 GHz rf, initial technology choices for the machine, and describes the range of experiments needed to characterize beam dynamics along with proposed instrumentation.

RPPT061 Linear Quadrupole Cooling Channel for a Neutrino Factory emittance, simulation, factory, acceleration 3526
  • C. Johnstone
    Fermilab, Batavia, Illinois
  • M. Berz, K. Makino
    MSU, East Lansing, Michigan
  Funding: Work supported by the U.S. Dept. of Energy under contract no. DE-AC02-76CH03000.

The staging and optimization in the design of a Neutrino Factory are critically dependent on the choice and format of accelerator. Possibly the simplest, lowest-cost scenario is a nonscaling FFAG machine coupled to a linear (no bending) transverse cooling channel constructed from the simplest quadrupole lens system, a FODO cell. In such a scenario, transverse cooling demands are reduced by a factor of 4 and no longitudinal cooling is required relative to acceleration using a Recirculating Linac (RLA). Detailed simulations further show that a quadrupole-based channel cools efficiently and over a momentum range which is well-matched to FFAG acceleration. Details and cooling performance for a quadrupole channel are summarized in this work.

RPPT063 Radiation Simulations and Development of Concepts for High Power Beam Dumps, Catchers and Pre-separator Area Layouts for the Fragment Separators for RIA simulation, radiation, target, ion 3594
  • R.M. Ronningen, V. Blideanu, G. Bollen, D. Lawton, D.J. Morrissey, B. Sherrill, A. Zeller
    NSCL, East Lansing, Michigan
  • L. Ahle, J.L. Boles, S. Reyes, W. Stein, A. Stoyer
    LLNL, Livermore, California
  • J.R. Beene, W. Burgess, H.K. Carter, D.L. Conner, T.A. Gabriel, L.K. Mansur, R. Remec, M.J. Rennich, D.W. Stracener, M. Wendel
    ORNL, Oak Ridge, Tennessee
  • H. Geissel, H. Iwase
    GSI, Darmstadt
  • I.C. Gomes, F. Levand, Y. Momozaki, J.A. Nolen, B. Reed
    ANL, Argonne, Illinois
  • L.H. Heilbronn
    LBNL, Berkeley, California
  Funding: This work is supported in part by Michigan State University, the US DOE, and the Gesellschaft für Schwerionenforschung, Germany.

The development of high-power beam dumps and catchers, and pre-separator layouts for proposed fragment separators of the Rare-Isotope Accelerator (RIA) facility are important in realizing how to handle the 400 kW in the primary beam. We will present examples of pre-conceptual designs of beam dumps, fragment catchers, and the pre-separator layout. We will also present examples of ongoing work on radiation simulations using the heavy-ion-transport code PHITS, characterizing the secondary radiation produced by the high-power ion beams interacting with these devices. Results on radiation heating of targets, magnet coils, associated hardware and shielding, component activation, and levels of radiation dose will be presented. These initial studies will yield insight into the impact of the high-power dissipation on fragment separator design, remote handling concepts, nuclear safety and potential facility hazard classification, shielding design, civil construction design, component design, and material choices. Furthermore, they will provide guidance on detailed radiation analyses as designs mature.

RPPT070 Status Report on the Installation of the Warm Sections for the Superconducting Linac at the SNS vacuum, SNS, linac, alignment 3828
  • R. Kersevan, D.P. Briggs, I.E. Campisi, J.A. Crandall, D.L. Douglas, T. Hunter, P. Ladd, C. Luck, R.C. Morton, K.S. Russell, D. Stout
    ORNL, Oak Ridge, Tennessee
  Funding: SNS is managed by UT-Battelle, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley and Oak Ridge.

The SNS superconducting linac (SCL) consists of 23 cryomodules (CMs), with possibly 9 additional CMs being added for future energy upgrade from 1 GeV to 1.3 GeV. A total of 32 warm sections separate the comparatively short CMs, and this allows a CM exchange within 48 hours, in order to meet demanding beam availability specifications. The 32 warm section chambers are installed between each pair of CMs, with each section containing a quadrupole doublet, beam diagnostics, and pumping. The chambers are approximately 1.6 m long, have one bellow installed at each end for alignment, and are pumped by one ion-pump. The preparation and installation of these chambers must be made under stringent clean and particulate-free conditions, in order to ensure that the performance of the SCL CMs is not compromised. This paper will discuss the development of the cleaning, preparation, and installation procedures that have been adopted for the warm sections, and the vacuum performance of this system.

RPPT071 Installation of the Spallation Neutron Source (SNS) Superconducting Linac SNS, vacuum, linac, acceleration 3838
  • D. Stout, I.E. Campisi, F. Casagrande, R.I. Cutler, D.R. Hatfield, M.P. Howell, T. Hunter, R. Kersevan, P. Ladd, W.H. Strong
    ORNL, Oak Ridge, Tennessee
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos and Oak Ridge.

The Spallation Neutron Source (SNS) cold linac consists of 11 medium beta (0.61) and 12 high beta (0.81) superconducting RF cryomodules, 32 intersegment quadrupole magnet/diagnostics stations, 9 spool beampipes for future upgrade cryomodules, and two differential pumping stations on either side of the linac. The cryomodules and spool beampipes were designed and manufactured by Jefferson Laboratory, and the quadrupole magnets and beam position monitors were designed and furnished by Los Alamos National Laboratory. The remaining items were designed by ORNL. At present we are installing and testing the cold linac. Experience gained during installation will be presented. The performance in terms of mechanical and cryogenic systems will be described.

ROPC001 SNS Warm Linac Commissioning Results linac, rfq, SNS, emittance 97
  • A.V. Aleksandrov
    ORNL, Oak Ridge, Tennessee
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos, and Oak Ridge.

The Spallation Neutron Source accelerator systems will deliver a 1.0 GeV, 1.4 MW proton beam to a liquid mercury target for neutron scattering research. The accelerator complex consists of an H- injector, capable of producing one-ms-long pulses at 60Hz repetition rate with 38 mA peak current, a 1 GeV linear accelerator, an accumulator ring and associated transport lines. The 2.5MeV beam from the Front End is accelerated to 86 MeV in the Drift Tube Linac, then to 185 MeV in a Coupled-Cavity Linac and finally to 1 GeV in the Superconducting Linac. The staged beam commissioning of the accelerator complex is proceeding as component installation progresses. The Front End, Drift Tube Linac and three of the four Coupled-Cavity Linac modules have been commissioned with beam at ORNL. Results and status of the beam commissioning program will be presented.

ROPC010 Testing, Installation, Commissioning and First Operation of the ISIS RFQ Pre-Injector Upgrade rfq, linac, vacuum, emittance 695
  • A.P. Letchford, D.C. Faircloth, D.J.S. Findlay, M. Perkins, A.F. Stevens, M. Whitehead
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  Situated at the Rutherford Appleton Laboratory (Oxon., UK), ISIS is currently the world's most intense pulse spallation neutron source, delivering 160 kW of 800 MeV protons to a tungsten target at 50 Hz. A major facility upgrade programme involves the construction of a second, 10 Hz target and an increase in the total beam power of up to 50% (i.e. up to 240 kW). To achieve the planned increase in average beam current to 300 μA whilst maintaining the current manageable levels of beam loss, four 2nd harmonic RF cavities have been installed in the synchrotron and the ageing Cockroft-Walton pre-injector in the linac has been replaced with a 665 keV, 202.5 MHz, 4-rod RFQ. This paper describes the extensive testing, installation, commissioning and successful initial operation of the RFQ pre-injector upgrade.  
FPAE007 A Project of the 2.5 GeV Booster-Synchrotron in BINP booster, injection, extraction, synchrotron 1039
  • V.A. Kvardakov, V. Barbashin, V. Kiselev, E.V. Kremyanskaya, E. Levichev, S.I. Mishnev, V. Petrov, A.N. Skrinsky, V.V. Smaluk, I. Zemlyansky
    BINP SB RAS, Novosibirsk
  A project of the 2.5 GeV booster synchrotron to provide effective injection of electron and positron beams into VEPP-2000 and VEPP-4M storage rings, and for future facilities, is developing in BINP. The beams are injected to synchrotron at 510 MeV energy from a damping ring, which is the part of the new injection facility. In this report, the synchrotron parameters are presented, the basic systems are briefly described.  
FPAE021 Alignment and Steering for Injection and Multi-Turn Operation of the University of Maryland Electron Ring (UMER) injection, dipole, electron, alignment 1709
  • M. Walter, G. Bai, S. Bernal, I. Haber, M. Holloway, R.A. Kishek, P.G. O'Shea, B. Quinn
    IREAP, College Park, Maryland
  • M. Reiser
    University Maryland, College Park, Maryland
  Funding: This work is funded by US Dept. of Energy grant numbers DE-FG02-94ER40855 and DE-FG02-92ER54178.

The injection line and main lattice for the University of Maryland Electron Ring (UMER) has been completed. The electron beam has been guided around the full 360 degrees of the ring. Beam steering and matching in the injection line is achieved with six quadrupole magnets and several small steering dipole magnets. The dipole component of an offset quadrupole and a pulsed dipole are used to achieve the 10 degree bend required from the injection line into the ring. The pulsed dipole is designed to operate with a short pulse (2 kV, -30 A, 100 ns flat top duration) for injection superimposed on a long pulse (300 V, 15 A, 20·10-6 s duration) for multiple beam passes. The beam is controlled in the recirculating ring with a regular lattice of 36 dipole and 72 quadrupole magnets. Initial experimental results of the beam transport and control will be presented.

FPAE028 Design of the High Intensity Exotic Beams SPIRAL 2 Project linac, ion, rfq, beam-losses 2044
  • A. Mosnier
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  • M.H. Moscatello
    GANIL, Caen
  The SPIRAL 2 facility will be able to deliver stable heavy ion beams and deuteron beams at very high intensity, allowing to produce and accelerate light and heavy rare ion beams. The driver will accelerate a 5 mA deuteron beam up to 20 MeV/u and also q/A=1/3 heavy ions up to 14.5 MeV/u. The injector consist of the ion sources, a 4-vane RFQ and the low and medium beam transfer lines. It is followed by an independently phased superconducting linac with compact cryostats separated with warm focusing sections. The overall design and results of simulations with combined errors, the results of tests of prototypes for the most critical components are presented.  
FPAE043 Transverse Tuning Scheme for J-PARC Linac linac, monitoring, coupling, emittance 2750
  • M. Ikegami, Z. Igarashi, S. Lee
    KEK, Ibaraki
  • H. Akikawa, K. Hasegawa, Y. Kondo, T. Ohkawa
    JAERI, Ibaraki-ken
  • H. Ao, S. Sato, T. Tomisawa, A. Ueno
    JAERI/LINAC, Ibaraki-ken
  In a high-intensity linac, precise transverse matching is essential for beam halo mitigation. In this paper, we present the supposed transverse tuning scheme for J-PARC linac and the planned beam diagnostic layout for it. Relevantly, we briefly touch upon the tuning scenario for the arc section and the transverse halo collimator system which are located between the linac and the succeeding ring.  
FPAE045 Design of the PEFP MEBT proton, rfq, linac, extraction 2881
  • J.-H. Jang, Y.-S. Cho, Y.-H. Kim, H.-J. Kwon
    KAERI, Daejon
  Funding: This work is supported by the 21C Frontier R&D program in the Ministry of Science and Technology of the Korean government.

A MEBT system of the PEFP(Proton Engineering Frontier Project) has to be installed after the 20MeV DTL where the beam will be supplied to the user group through a beam extraction system. Until now we don't have a plan to put in some matching devices between the RFQ and 20MeV DTL except using the four quadrupole magnets in the first DTL tank as transverse matching tools. The MEBT plays the key role to match the 20MeV output beam into the next accelerator in the longitudinal direction as well as transverse one. This report shows the basic concept and the design status of the system.

FPAE047 Test Scheme Setup for the PEFP 20MeV DTL beam-losses, resonance, proton, klystron 2965
  • H.-S. Kim, Y.-S. Cho, Y.-H. Kim, H.-J. Kwon, K.T. Seol
    KAERI, Daejon
  • Y.-S. Hwang
    SNU, Seoul
  Funding: This work is supported by the 21C Frontier R&D program in the Ministry of Science and Technology of the Korean government.

A 100MeV proton accelerator is under development for the Proton Engineering Frontier Project (PEFP). The goal of the first stage of the project is to develop a 20MeV accelerator and the initial test of the 20MeV accelerator will be made. The DTL of 20 MeV accelerator consists of four tanks and will be driven with single klystron, which gives rise to some unique problems with regard to the way of independent resonance control for each tank. Some changes made in the LLRF for reducing phase or amplitude error of cavities affect all of four tanks simultaneously, for which it is not possible to use LLRF for individual control of phase and amplitude of each tank. For independent control of each tank, we are going to use the temperature control of the drift tubes as a frequency tuner. During the initial test of the DTL, the phase of each tank will be synchronized with the first tank phase, and beam based test will be performed as if all of tanks were single unit. The detailed description of the test scheme and the analysis results will be given in this paper.

FPAE048 Fabrication of the PEFP 3MeV RFQ Upgrade rfq, proton, vacuum, coupling 3010
  • H.-J. Kwon, Y.-S. Cho, J.-H. Jang, H.-S. Kim, Y.-H. Kim
    KAERI, Daejon
  Funding: This work is supported by the 21C Frontier R&D program in the Ministry of Science and Technology of the Korean government.

A 100MeV proton accelerator has been developed at PEFP (Proton Engineering Frontier Project) as a 21C Frontier Project. The goal of the first stage of the project is to develop a 20MeV accelerator. The 20MeV accelerator consists of ion source, LEBT, 3MeV RFQ and 20MeV DTL. The 3MeV RFQ was already installed and being tested. During preliminary test, some problems, such as the resonant frequency and field profile tuning, sharp edge in the vane end, inadequate RF seals have been found out. Therefore, it was decided to fabricate another RFQ. The RFQ upgrade includes some characteristics such as constant voltage profile, adoption of transition cell which are different from present one. In this paper, the fabrication of the PEFP 3MeV RFQ upgrade are presented.

FPAE050 Injector Linac for the BNL Super Neutrino Beam Project linac, SNS, proton, insertion 3129
  • D. Raparia, J.G. Alessi, A. Ruggiero, W.-T. Weng
    BNL, Upton, Long Island, New York
  Funding: This work was performed under the auspices of the U.S. DOE, Contract No. DE-AC02-98H10886.

BNL plans to upgrade the AGS proton beam from the current 0.14 MW to higher than 1.0 MW and beyond for such a neutrino facility. We have examined possible upgrades to the AGS complex that would meet the requirements of the proton beam for a 1.0 MW neutrino superbeam facility. We are proposing to replace part of the existing 200 MeV linac with coupled cavity structure from 116 MeV to 400 MeV and then add additional 1.1 GeV superconducting linac to reach a final energy of 1.5 GeV for direct H- injection into the AGS. We will present possible choices for the upgrade and our choice and its design.

FPAE053 Isobar Suppression by Photodetachment in a Gas-Filled RF Quadrupole Ion Guide ion, rfq, laser, photon 3250
  • Y. Liu, J.R. Beene, C.C. Havener, J. F. Liang
    ORNL, Oak Ridge, Tennessee
  • A.C. Havener
    University of Tennessee, Knoxville, Tennessee
  Funding: Managed by UT-Battelle, LLC, for the U.S. DOE under contract DE-AC05-00OR22725. Co-author Aaron Havener was under a U.S. DOE Science Undergraduate Laboratory Internship.

A novel method is described for selective suppression of isobar contaminants in negative radioactive ion beams. Negative ion beams extracted from an ion source were decelerated to low energies and injected into a gas-filled radio-frequency quadrupole (RFQ) ion guide where the ions were cooled and unwanted ions were selectively removed by non-resonant photodetachment with photons of sufficient energy. Simulation studies show that the laser-ion interaction time in a 40 cm long RFQ ion guide can be on the order of milliseconds, thus, high efficiency photodetachment is possible with commercially available CW lasers. There are a number of adjacent-Z species whose negative ions are such that photodetachment can be used to suppress the unwanted negative ion species while leaving the species of interest intact. Examples of particular interest include suppressing the 56Co- component in a mixed 56Ni- + 56Co- beam and the 17O- component in a mixed 17O- + 17F- beam. In a proof–of-principle experiment a CW Nd:YAG laser at 1064 nm wavelength was used to selectively remove Co- ions in the (Ni, Co) pair. With laser power on the order of 3 W, 95% of Co- beams were suppressed while only 10% of Ni- beams were neutralized in a He-filled RFQ guide.

FPAE067 Present Design and Calculation for the Injection-Dump Line of the RCS at J-PARC injection, beam-losses, emittance, linac 3739
  • P.K. Saha, N. Hayashi, H. Hotchi, Y. Irie, F. Noda, T. Takayanagi
    JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • S. Machida, I. Sakai
    KEK, Ibaraki
  The RCS(rapid cycling synchrotron) of J-PARC(Japan proton accelerator research complex) acts as an injector to the main ring as well as a high-power beam for the spallation neutron source at a repetition rate of 25 Hz, where at present the injection and the extraction beam energy are chosen to be 0.181 GeV and 3.0 GeV, respectively. The present work concerns on the present design and calculations for the injection-dump line of the RCS, which includes, 1) an accurate aperture list of all elements taking into account a wide range of the betatron tune, effect of changing injection modes, multiple trajectories of different particles after the charge-exchange foil( like H0 from the H- and H- beam itself)and 2) an accurate estimation of the uncontrolled beam losses especially from the H0-excited states, multiple coulomb scattering at the charge-exchange foil and also the lorentz stripping loss at the septum magnets so as to optimize them concerning mainly the radiation issues as well as for the hands-on maintenance.  
FPAE072 RF-Kicker System for Secondary Beams at NSCL/MSU kicker, secondary-beams, ion, cyclotron 3880
  • D. Gorelov, V. Andreev, D. Bazin, M. Doleans, T.L. Grimm, F. Marti, J. Vincent, X. Wu
    NSCL, East Lansing, Michigan
  The design and construction of a radio frequency (RF) kicker system at the National Superconducting Cyclotron Laboratory (NSCL), Michigan State University (MSU) has been proposed. This RF kicker system will be used to purify secondary beams of rare isotopes after the existing A1900 Fragment Separator and will open a wide range of possibilities for new experiments at the forefront of nuclear science. The proposed system is studied as an efficient alternative to the traditional approach using Wien Filter. Rare neutron deficient secondary beams are challenging to purify because of the presence of intense contaminants that cannot be removed by the traditional energy loss method. However, velocity differences resulting in time-of-flight differences can be used for the effective separation of the beams transversely using the time-varying electromagnetic fields of the RF kicker. Its technical design will be presented together with the beam dynamics analysis of a secondary beam in realistic 3D electromagnetic fields. The expected purification improvement of the exotic beams for the foreseen nuclear physics experiments will be shown in details.  
FPAE074 Beam Parameter Measurement and Control at the SNS Target target, diagnostics, emittance, SNS 3913
  • M.A. Plum, M. Holding, T. McManamy
    ORNL, Oak Ridge, Tennessee
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos, and Oak Ridge.

The spallation neutron production target at the SNS facility is designed for 1.4 MW beam power. Both beam position and profile must be carefully controlled within narrow margins to avoid damage to the target. The position must be within 2 mm of the target center, and 90% of the beam must be within the nominal 70 mm x 200 mm spot size, without exceeding 0.18 A/m2 peak beam current density. This is a challenging problem, since most of the diagnostics are 9 m upstream of the target, and because the high beam power limits the lifetime of intercepting diagnostics. Our design includes a thermocouple halo monitor approximately 2 m upstream of the target face, and a beam position monitor, an insertable harp profile monitor, and a beam shape monitor approximately 9 m upstream. In this paper we will discuss our strategy to commission the beam delivery system and to meet target requirements during nominal operation.

FPAE076 The System of Nanosecond 280-keV-He+ Pulsed Beam ion, ion-source, target, focusing 3982
  • P. Junphong, Mr. Ano, Mr. Lekprasert, Dr. Suwannakachorn, N. Thongnopparat, T. Vilaithong
    FNRF, Chiang Mai
  • H. Wiedemann
    SLAC, Menlo Park, California
  Funding: We would like to acknowledge the support of the Thailand Research Fund, the National Research Council of Thailand, the Thai Royal Golden Jubilee Scholarship Program, the Faculty of Science, and the Graduate School of Chiang Mai University.

At Fast Neutron Research Facility,the 150 kV-pulseds neutron generator is being upgraded to produce a 280-keV-pulsed-He beam for time-of-flight Rutherford backscattering spectrometry. It involves replacing the existing beam line elements by a multicusp ion source, a 400-kV accelerating tube, 45o-double focusing dipole magnet and quadrupole lens. The Multicusp ion source is a compact filament-driven of 2.6 cm in diameter and 8 cm in length. The current extracted is 20.4 μA with 13 kV of extraction voltage and 8.8 kV of Einzel lens voltage. The beam emittance has been found to vary between 6-12 mm mrad. The beam transport system has to be redesigned based on the new elements. The important part of a good pulsed beam depends on the pulsing system. The two main parts are the chopper and buncher. An optimized geometry for the 280 keV pulsed helium ion beam will be presented and discussed. The PARMELA code has been used to optimize the space charge effect, resulting in pulse width of less than 2 ns at a target. The calculated distance from a buncher to the target is 4.6 m. Effects of energy spread and phase angle between chopper and buncher have been included in the optimization of the bunch length.

FPAT010 Automated Beam Steering Using Optimal Control target, controls, simulation, lattice 1213
  • C.K. Allen
    LANL, Los Alamos, New Mexico
  • E. Schuster
    Lehigh University, Bethlehem, Pennsylvania
  Funding: Work supported by the U.S. Department of Energy.

We present an optimal control strategy for beam steering where the operator can specify a variety of optimality conditions by selecting a parameter set describing an optimally steered beam. Novel approaches here include the ability to base optimality on the beam state throughout the entire beamline, rather than just at BPM locations. Moreover, we also may use the trajectory slope to base our optimality criteria. To achieve this feature we must introduce model dependency. Specifically, we predict the state of the beam from BPM measurements, the set-point of the steering magnets, and a model of beam behavior. The predictions are then used to calculate the optimum setting for steering magnets. The optimal control problem has rich mathematical structure that can be exploited and we cover some topics as they apply to accelerator systems.


FPAT011 Fast Automated Decoupling at RHIC coupling, monitoring, resonance, instrumentation 1254
  • J. Beebe-Wang
    BNL, Upton, Long Island, New York
  Funding: Work performed under the auspices of the U.S. DOE.

Coupling correction is essential for the operational performance of RHIC. The independence of the transverse degrees of freedom makes diagnostics and tune control easier, and it is advantageous to operate an accelerator close to the coupling resonance to minimize nearby nonlinear sidebands. An automated decoupling application has been developed at RHIC for coupling correction during routine operations. The application decouples RHIC globally by minimizing the tune separation through finding the optimal settings of two orthogonal skew quadrupole families. The program provides options of automatic, semi-automatic and manual decoupling operations. It accesses tune information from all RHIC tune measurement systems: the PLL (Phase Lock Loop), the high frequency Schottky system, and the tune meter. It also supplies tune and skew quadrupole scans, finding the minimum tune separation, display the real time results and interface with the RHIC control system. We summarize the capabilities of the decoupling application, and discuss the operational protections incorporated in the program. We also report the decoupling performances with the application during the RHIC 2005 run.

FPAT026 The Dynamic Aperture of an Electrostatic Quadrupole Lattice simulation, lattice, beam-losses, focusing 1946
  • C.M. Celata, F.M. Bieniosek, P.A. Seidl
    LBNL, Berkeley, California
  • A. Friedman, D.P. Grote
    LLNL, Livermore, California
  • L.R. Prost
    Fermilab, Batavia, Illinois
  Funding: Work supported by the U.S. DOE, under contract numbers DE-AC03-76SF00098 and W-7405-Eng-48.

In heavy-ion-driven inertial fusion accelerator concepts, dynamic aperture is important to the cost of the accelerator, most especially for designs which envision multibeam linacs, where extra clearance for each beam greatly enlarges the transverse scale of the machine. In many designs the low-energy end of such an accelerator uses electrostatic quadrupole focusing. The dynamic aperture of such a lattice has been investigated for intense, space-charge-dominated ion beams using the 2-D transverse slice version of the 3-D particle-in-cell simulation code WARP. The representation of the focusing field used is a 3-D solution of the Laplace equation for the biased focusing elements, as opposed to previous calculations which used a less-accurate multipole approximation. 80% radial filling of the aperture is found to be possible. Results from the simulations, as well as corroborating data from the High Current Experiment at LBNL, will be presented.

FPAT030 Parametric Studies of Image-Charge Effects in Small-Aperture Alternating-Gradient Focusing Systems beam-losses, vacuum, simulation, focusing 2128
  • J.Z. Zhou, C. Chen
    MIT/PSFC, Cambridge, Massachusetts
  Funding: The U.S. Department of Energy, Office of High-Energy Physics, Grant No. DE-FG02-95ER40919, Office of Fusion Energy Science, Grant No. DE-FG02-01ER54662, and in part by Air Force Office of Scientific Research, Grant No. F49620-03-1-0230.

Image charges have important effects on an intense charged-particle beam propagating through an alternating-gradient (AG) focusing channel with a small circular aperture. This is especially true with regard to chaotic particle motion, halo formation, and beam loss.* In this paper, we examine the dependence of these effects on system parameters such as the filling factor of the AG focusing field, the vacuum phase advance, the beam perveance, and the ratio of the beam size to the aperture. We calculate the percentage of beam loss to the conductor wall as a function of propagating distance and aperture, and compare theoretical results with simulation results from the particle-in-cell (PIC) code PFB2D.

*Zhou, Qian and Chen, Phys. Plasmas 10, 4203 (2003).

FPAT058 Creating EPICS Soft Channels the Easy Way with sddspcas: Features and Applications simulation, emittance, lattice, photon 3429
  • R. Soliday, M. Borland
    ANL, Argonne, Illinois
  Funding: This work is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38.

Using sddspcas, a portable channel access server that is configured by SDDS input files, it is relatively simple to create process variables (PVs). It can be run in a standalone mode or it can be run so that the PVs are checked to ensure that they don’t conflict with other IOCs or portable channel access servers. It can also be run using the Run Control facility to prevent additional instances of the same sddspcas from being run. The SDDS configuration file provides the PV names, upper and lower limits, units, element counts if the PVs are waveforms, and the types of PVs. Valid types include various precision floats and integers as well as strings. One simple application of this program is that software developers can quickly test their code without requiring the coordination needed to update an IOC database to create PVs. Further details of the features, configuration, and applications of sddspcas will be discussed.

FPAT060 An FPGA-Based Quench Detection and Protection System for Superconducting Accelerator Magnets superconducting-magnet, power-supply, extraction, interaction-region 3502
  • R. H. Carcagno, SF. Feher, M.J. Lamm, A. Makulski, R. Nehring, D.F. Orris, Y.M.P. Pischalnikov, M. Tartaglia
    Fermilab, Batavia, Illinois
  A new quench detection and protection system for superconducting accelerator magnets was developed at the Fermilab's Magnet Test Facility (MTF). This system is based on a Field-Programmable Gate Array (FPGA) module, and it is made of mostly commerically available, integrated hardware and software components. It provides most of the functionality of our existing VME-based quench detection and protection system, but in addition the new system is easily scalable to protect multiple magnets powered independently and has a more powerful user interface and analysis tools. First applications of the new system will be for testing corrector coil packages. In this paper we describe the new system and present results of testing LHC Interaction Region Quadrupole (IRQ) correctors.  
FPAT079 Data Base Extension for the Ensemble Model Using a Flexible Implementation simulation, multipole, sextupole, space-charge 4036
  • W. Ackermann, T. Weiland
    TEMF, Darmstadt
  Funding: Work supported by DESY, Hamburg.

To guarantee an adequate design and a proper functionality of various machine components it is of great importance to perform detailed studies of charged particle transport. However, it is often not necessary to initiate individual kinetic simulations. When the evolution of integral quantities is of research interest, it is worth treating an investigated particle ensemble as a whole and applying a macroscopic formulation. Using a collision-less kinetic approach, the simplified model is derived from the well-known Vlasov equation. Instead of solving directly this equation, one can use moments of the density function obtained by means of an averaging process. This formalism had been implemented into the beam dynamics simulation program V-Code and a fundamental database of various beam line elements like cavities, drift spaces, solenoids, quadrupoles and steerers was set up. A flexible realization of the C++ code representing the cavities and the drift spaces can be automatically used for an arbitrary order of moments applying a symbolic algebra program. A useful extension to the remaining beam line elements together with appropriate simulation results is presented in the paper.

FPAT085 The TAO Accelerator Simulation Program linac, simulation, damping, lattice 4159
  • D. Sagan
    Cornell University, Department of Physics, Ithaca, New York
  • J.C. Smith
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  Funding: NSF and DOE.

A new accelerator design and analysis simulation environment based on the BMAD relativistic charged particle dynamics library is in development at Cornell University. Called TAO (Tool for Accelerator Optimization), it is a machine independent program that implements the essential ingredients needed to solve simulation problems. This includes the ability to: 1. Design lattices subject to constraints, 2. Simulate errors and changes in machine parameters, and 3. Simulate machine commissioning including simulating data measurement and correction. TAO is designed to be easily customizable so that extending it to solve new and different problems is straight forward. The capability to simultaneously model multiple accelerator lattices, both linacs and storage rings, and injection from one lattice to another allows for the design and commissioning of large multi stage accelerators. It can also simultaneously model multiple configurations of a single lattice. Single particle, particle beam and macroparticle tracking is implemented. Use of TAO with both the International Linear Collider and the Cornell Energy Recovery Linac are provided as examples.

FOAA005 Mechanical Vibration Measurements on TTF Cryomodules monitoring, instrumentation, linac, vacuum 434
  • A. Bosotti, C. Pagani, R. Paparella, P. Pierini, D. Sertore
    INFN/LASA, Segrate (MI)
  • R. De Monte, M. Ferianis
    ELETTRA, Basovizza, Trieste
  • R. Lange
    DESY, Hamburg
  Few of the TTF cryomodules have been equipped with Wire Position Monitors (WPM) for the on line monitoring of cold mass movements during cool-down, warm-up and operation. Each sensor can be used as a detector for mechanical vibrations of the cryostat. A Digital Receiver board is used to sample and analyze with high frequency resolution, the WPM picked up signals, looking to its amplitude modulation in the microphonic frequency range. Here we review and analyze the data and the vibration spectra taken during operation of the TTF cryomodules # 4 and #5.  
FOAD005 Commissioning of the University of Maryland Electron Ring (UMER) injection, space-charge, dipole, emittance 469
  • S. Bernal, G. Bai, D.W. Feldman, R. Feldman, T.F. Godlove, I. Haber, J.R. Harris, M. Holloway, R.A. Kishek, J.G. Neumann, P.G. O'Shea, C. Papadopoulos, B. Quinn, D. Stratakis, K. Tian, J.C. Tobin Thangaraj, M. Walter, M. Wilson
    IREAP, College Park, Maryland
  • M. Reiser
    University Maryland, College Park, Maryland
  Funding: This work is funded by the U.S. Department of Energy under grants DE-FG02-94ER40855 and DE-FG02-92ER54178, and the office of Naval Research under grant N00014-02-1-0914.

The University of Maryland electron ring (UMER) is a low-energy, high current recirculator for beam physics research. The ring is completed for multi-turn operation of beams over a broad range of intensities and initial conditions. UMER is addressing issues in beam physics with relevance to many applications that rely on intense beams of high quality. Examples are advanced accelerators, FEL’s, spallation neutron sources and future heavy-ion drivers for inertial fusion. We review the motivation, ring layout and operating conditions of UMER. Further, we present a summary of beam physics areas that UMER is currently investigating and others that are part of the commissioning plan: from transverse beam dynamics (matching, halo formation, strongly asymmetric beams, space-charge waves, etc), longitudinal dynamics (bunch capture/shaping, evolution of energy spread, longitudinal space-charge waves, etc.) to future upgrades and planned research (acceleration and resonance traversal, modeling of galactic dynamics, etc.) We also emphasize the computer simulation work that is an integral part of the UMER project.