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optics

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MOZAG02 Short Bunches in Electron Storage Rings and Coherent Synchrotron Radiation radiation, storage-ring, electron, synchrotron 26
 
  • G. Wuestefeld
    BESSY GmbH, Berlin
  Significant progress has been made in recent years in achieving short bunches in third generation synchrotron light sources and the generation of coherent radiation. This talk will review the properties of the radiation and the associated beam dynamics, and will discuss optics issues and the limits of the available techniques.  
slides icon Slides  
 
MOPC045 First Measurement Results of the PSI 500kV Low Emittance Electron Source laser, emittance, cathode, electron 169
 
  • M. Pedrozzi, Å. Andersson, R. J. Bakker, R. Ganter, C. Gough, C. P. Hauri, R. Ischebeck, S. Ivkovic, Y. Kim, F. Le Pimpec, K. B. Li, P. Ming, A. Oppelt, M. Paraliev, T. Schietinger, V. Schlott, B. Steffen, A. F. Wrulich
    PSI, Villigen
  • S. C. Leemann
    MAX-lab, Lund
  The Paul Scherrer Insitute (PSI) is presently developing a low emittance electron source for the PSI-XFEL project. The target beam parameters at the source are I=5.5 A, Q=0.2 nC and a slice emittance below 0.2 mm.mrad. The gun concept consists of a high gradient "diode“ stage followed by a two-frequency two-cell cavity to allow fine tuning of the longitudinal phase space. This paper reports on the first experimental results obtained with the PSI 500 kV test stand. The facility consists of a 500 kV diode stage followed by a diagnostic beam line including an emittance monitor. An air-core transformer based high voltage pulser is capable of delivering a pulse of 250 ns FWHM with amplitude up to 500 kV. The diode gap between two mirror polished electrodes is adjustable to allow systematic gradient studies. The electrons are produced by a 266nm UV laser delivering 4μJoules on the Cu-cathode.  
 
MOPD018 Energy Dependent Measurements of Gamma and Neutron Dose at ANKA radiation, undulator, storage-ring, electron 484
 
  • I. Birkel, E. Huttel, A.-S. Müller, N. J. Smale, P. Wesolowski
    FZK, Karlsruhe
  Gamma and neutron radiation dose rate around an electron storage ring are proportional to the number of lost particles in a certain time. They are depending on beam energy, current, lifetime and operating conditions of the storage ring. The online area monitoring network of ANKA makes it possible to measure the radiation from the decaying beam at eight stations distributed all over the ANKA hall. Measurements of the ambient dose at beam energies from 800 MeV to 2.5 GeV show higher dose rates around and in the forward direction of insertion devices and other devices with restricted horizontal or vertical aperture.  
 
MOPP005 The 2 mrad Crossing Angle Scheme for the International Linear Collider extraction, quadrupole, multipole, linear-collider 556
 
  • R. Appleby
    UMAN, Manchester
  • D. Angal-Kalinin
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • P. Bambade, S. Cavalier, G. Le Meur, F. Touze
    LAL, Orsay
  • Y. Iwashita
    Kyoto ICR, Uji, Kyoto
  The present baseline configuration of the ILC has a 14 mrad crossing angle between the beams at the interaction point. This allows easier extraction of the beams after collisions, but imposes on the other hand more constraints on the control of the beams prior to colliding them. Moreover, some limitations to physics capabilities arise, in particular because of the degraded very forward electromagnetic detector hermeticity and because calibration procedures for (gaseous) tracking detectors become more complex. To mitigate these problems, alternative configurations with very small crossing angles are studied. A new version of the 2 mrad layout was designed last year, based on simpler concepts and assumptions. The emphasis of this new scheme was to satisfy specifications with as few and feasible magnets as possible, in order to reduce costs. Recent progress designing several of the magnets involved and the particular vacuum chamber needed in the shared part of the beam line is reported.  
 
MOPP010 Experimental Studies on Drive Beam Generation in CTF3 linac, extraction, injection, quadrupole 571
 
  • R. Corsini, S. Bettoni, S. Doebert, P. K. Skowronski, F. Tecker
    CERN, Geneva
  • C. Biscari, A. Ghigo
    INFN/LNF, Frascati (Roma)
  • Y.-C. Chao
    Jefferson Lab, Newport News, Virginia
  The objective of the CLIC Test Facility CTF3, built at CERN by an international collaboration, is to demonstrate the main feasibility issues of the CLIC two-beam technology by 2010. CTF3 consists of a 150 MeV electron linac followed by a 42 m long delay loop, an 84 m combiner ring and a two-beam test area. One key-issue studied in CTF3 is the efficient generation of a very high current drive beam, used in CLIC as the power source for the acceleration of the main beam to multi-TeV energies. The beam current is first doubled in the delay loop and then multiplied again by a factor four in the combiner ring by interleaving bunches using transverse deflecting RF cavities. The combiner ring and the connecting transfer line have been installed and put into operation in 2007. In this paper we give the status of the commissioning, illustrate the beam optics measurements, discuss the main issues and present the results of the combination tests.  
 
MOPP046 Collimation Optimizations, Capture Efficiency, and Primary-Beam Power Loss in the ILC Positron Source positron, target, collimation, injection 649
 
  • F. Zhou, Y. Nosochkov, J. Sheppard
    SLAC, Menlo Park, California
  • W. Liu
    ANL, Argonne, Illinois
  The ILC positron beam generated from a thin Ti target has a wide energy spread and large transverse divergence. With the collection optics immediately downstream of the target and pre-acceleration to 125 MeV, the collected positron beam still has a long tail of positrons with low energies and large transverse divergence, which will be lost in the rest of the ILC positron source beamline. A collimation system is proposed and optimized for the case of a shielded target with quarter-wave transformation collection optics so that the power loss in the magnets and RF structures is effectively controlled within the acceptable level and in the damping ring (DR) within 640 W, assuming 3× 1010 of the captured positrons per bunch in the DR. In this case, the capture efficiency and DR injection efficiency are 13% and 99.8%, respectively. The lower capture efficiency is expected to result in higher injection efficiency and therefore, a lower power loss in the DR. The capture efficiency for the cases of a shielded target with flux concentrator and 5-T immersed target with flux concentrator is 20% and 30%, respectively, with the collimation system.  
 
MOPP059 Study for ILC Damping Ring at KEKB emittance, electron, damping, sextupole 676
 
  • K. Ohmi, J. W. Flanagan, H. Fukuma, K.-I. Kanazawa, H. Koiso, M. Masuzawa, Y. Ohnishi, K. Oide, Y. Suetsugu, M. Tobiyama
    KEK, Ibaraki
  • M. T.F. Pivi
    SLAC, Menlo Park, California
  ILC damping ring consists of very low emittance electron and positron storage rings. It is necessary for ILC damping ring to study electron cloud effects in such low emittance positron ring. We propose a low emittance operation of KEKB to study the effects.  
 
MOPP062 Optics Design Considerations for the CLIC Pre-damping Rings emittance, focusing, quadrupole, damping 685
 
  • Y. Papaphilippou
    CERN, Geneva
  • F. Antoniou
    National Technical University of Athens, Zografou
  The CLIC pre-damping rings have to accommodate a large emittance beam, coming in particular from the positron source and reduce its size to low enough values for injection into the main damping rings. Linear lattice design options based on an analytical approach for theoretical minimum emittance cells are presented. In particular the parameterisation of the quadrupole strengths and optics functions with respect to the emittance and drift lengths is derived. Complementary considerations regarding constraints imposed by positron stacking and input momentum spread are also considered.  
 
TUOAG02 Commissioning of BEPCII luminosity, injection, vacuum, electron 959
 
  • J. Q. Wang, L. Ma, C. Zhang
    IHEP Beijing, Beijing
  BEPCII is the upgrade project of Beijing Electron Positron Collider (BEPC), serving continuously for both high energy physics experiment and light soure use. As an e+-e- collider, BEPCII will operate in the beam energy region of 1-2.1 GeV with design luminosity of 1*1033cm-2s-1 at 1.89 GeV. The beam commissioning of BEPCII storage rings started out in Nov. 2006. From Nov. 2006 to Aug. 2007, the phase one commissioning was carried out successfully with the so called backup scheme adopting conventional magnets in the IR intead of the superconducting insertion magnets (SIM). After the SIM was intalled into the interaction region, phase two commissioning began in Oct. 2007. The tuning method for high luminosity but low background was extensively studied during phase two, and the beam current has reached more than 1/3 of the design of 0.91 A. The third phase of beam commissioning is planned in May this year after the detector is moved into the on-line position. It is expected that the luminosity would reach to about 30% of its design specification. This paper describes the procedure of beam commissioning of BEPCII and focuses on results of its second phase.  
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TUXM01 Ultra Low Emittance Light Sources emittance, lattice, damping, controls 988
 
  • J. Bengtsson
    BNL, Upton, New York
  The talk will cover the special issues for reaching sub-nm emittance in a storage ring. Effects of damping wigglers, intra-beam scattering and life-time issues, instabilities, dynamic aperature optimisation, control of optics, dispersion and orbit correction. Results and example of upgrades to existing machine and NSLS-II and Petra-III should be given.

First priority

 
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TUOCM02 X-ray Monitor Based on Coded-aperture Imaging for KEKB Upgrade and ILC Damping Ring photon, damping, synchrotron, monitoring 1029
 
  • J. W. Flanagan, H. Fukuma, S. Hiramatsu, H. Ikeda, K.-I. Kanazawa, T. Mitsuhashi, J. Urakawa
    KEK, Ibaraki
  • J. P. Alexander
    CLASSE, Ithaca
  • M. A. Palmer
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  • G. S. Varner
    UH, Honolulu, HI
  We present here design considerations for an x-ray monitor for high-resolution (a few um) and fast response (sub-nanosecond) for beam profile measurements to be used at an upgraded KEKB and/or ILC damping ring. The optics for the monitor are based on a technique borrowed from x-ray astronomy, coded-aperture imaging, which should permit broad-spectrum, low-distortion measurements to maximize the observable photon flux per bunch. Coupled with a high-speed digitizer system, the goal is to make sub-bunch-length, turn-by-turn measurements of beam profile and position.  
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TUPC001 Optics Calculation and Emittance Measurement toward Automatic Beam Tuning of Linac linac, emittance, gun, simulation 1035
 
  • T. Asaka, H. Dewa, H. Hanaki, T. Kobayashi, A. Mizuno, S. Suzuki, T. Taniuchi, H. Tomizawa, K. Yanagida
    JASRI/SPring-8, Hyogo-ken
  • T. Watanabe
    SES, Hyogo-pref.
  The SPring-8 1-GeV linac has a total of 13 sets of 80MW klystron units. In usual operation, two klystron units are driven as the standby unit. If there's any problem with an arbitrary klystron unit, the beam operation is able to restart immediately by using the standby unit. In that case, the optimization of beam optics has carried out using beam screen monitors. This beam tuning spend about one hour. In order to reduce the beam tuning time, we are promoting the development of the automatic beam optics tuning system. Since the complete understanding of the beam envelope is important, the particles tracking simulation of the linac was carried out by using PARMELA and SAD. Five sets of beam size monitors were installed in the end of the linac for measurement of the real beam envelope. In a beam study applying the simulation results, the beam waist was actually formed at the 10-m long drift space after the 1-GeV chicane section as predicted by SAD. The values of the measured beam emittance were smaller than the simulation results.  
 
TUPC011 Micron Size Laser-wire System at the ATF Extraction Line laser, electron, diagnostics, simulation 1065
 
  • A. Aryshev, G. A. Blair, S. T. Boogert, G. E. Boorman, A. Bosco, L. Corner, L. Deacon, N. Delerue, B. Foster, F. Gannaway, D. F. Howell, V. Karataev, L. J. Nevay, M. Newman, R. Senanayake, R. Walczak
    JAI, Egham, Surrey
  • H. Hayano, N. Terunuma, J. Urakawa
    KEK, Ibaraki
  The ATF extraction line laser-wire system has recently been upgraded allowing the measurement of micron scale transverse size electron beams. We report on the hardware upgrades, including focusing lens, laser and mechanical systems. First measurements using the new system from recent operation at the ATF in KEK are presented.  
 
TUPC030 Transverse Electron Beam Size Effect on the Bunch Profile Determination with Coherent Radiation Diagnostics radiation, electron, diagnostics, free-electron-laser 1113
 
  • O. Grimm, H. Delsim-Hashemi, J. Rossbach
    Uni HH, Hamburg
  • V. Balandin, N. Golubeva
    DESY, Hamburg
  Longitudinal diagnostics of electron bunches can be done by measurement of coherent radiation (e.g., in the form of transition radiation) and subsequent extraction of the form factor. By measuring short wavelengths, fine structures in the bunch can be resolved. However, the form factor depends on the three-dimensional charge density distribution, and the usual practice of considering only a one-dimensional line charge in interpreting the radiation spectra is questionable, as the finite transverse extend of the electron bunch can reduce the form factor magnitude at short wavelengths. An experimental study of this issue using a two stage single shot spectrometer has been carried out at the FLASH free-electron laser at DESY, Hamburg. The coherent transition radiation spectra for two beam optics settings were recorded and compared. In one setting the transverse beam size at the transition radiation target screen has been blown up by a factor of about 3.5 compared to the second setting. The ratio of these two spectra shows a suppression of radiation intensity at short wavelengths, as expected from a theoretical calculation. In this paper the result of this study is presented.  
 
TUPC047 Optical Transition Radiation Interferometry for the A0 Photoinjector electron, scattering, vacuum, radiation 1164
 
  • G. M. Kazakevich
    BINP SB RAS, Novosibirsk
  • H. T. Edwards, R. P. Fliller, S. Nagaitsev, J. Ruan, R. Thurman-Keup
    Fermilab, Batavia, Illinois
  OTR interferometry (OTRI) is a promising diagnostic technique and was successfully developed and used for investigation of relativistic beams. For mid-energy accelerators the technique is traditionally based on thin polymer films (the first one is transparent for visible light) providing the beam multiple scattering of about 1 mrad or less. The disadvantage of these films is the unacceptable vacuum properties for photoinjectors and accelerators using superconducting cavities. We studied the application of thin mica sheets for OTRI diagnostics at the A0 Photoinjector in comparison with 2.5 μm thick Mylar films. This diagnostic is also applicable for the ILCTA-NML accelerator test facility that is planned at Fermilab. The experimental setups of the OTR interferometer for the A0 Photoinjector are described in the report. Results of simulations and measurements and comparison of the results obtained using Mylar and Mica-based interferometers are presented and discussed.  
 
TUPC073 A Real-time Bunch Length Terahertz Interferometer radiation, diagnostics, electron, linac 1218
 
  • G. Andonian, G. Travish
    UCLA, Los Angeles, California
  • S. Boucher, P. Frigola, A. Y. Murokh
    RadiaBeam, Marina del Rey
  With the recent development of advanced photoinjectors and next generation light sources, the progression towards high-current, ultra-short beams is very important. The measurement of these short pulses, with sub-picosecond resolution is essential for successful beam operation and optimization. This paper describes the development of a real-time, shot-to-shot bunch length diagnostic utilizing a novel beam auto-correlation technique.  
 
TUPC076 TTF HOM Data Analysis with Curve Fitting Method dipole, polarization, linac, simulation 1227
 
  • S. Pei, C. Adolphsen, K. L.F. Bane, Z. Li, J. C. Smith
    SLAC, Menlo Park, California
  To investigate the possibility of using HOM signal induced in SC cavities as beam and cavity diagnostics, experiments and analyses based on SVD have been done, which are very successful. In this paper, we described one new method based on curve fitting to analyze the HOM signal data, some results have been obtained. The new method can be used to extract the HOM mode frequency, Q and relative phase from the data. On the other hand, this method can also be used to find the HOM mode center, polarization axis, mode axis along the cavity, while careful handling of beam timing information need to be considered in analysis. Comparing with SVD, this method is more physical, and can also be used in the beam diagnostic data analysis to obtain the beam position and beam trajectory angle.  
 
TUPC117 Beam Based Alignment of Quadrupole Triplets by Use of MATLAB Based Modeling quadrupole, storage-ring, survey, alignment 1341
 
  • O. Kopitetzki, D. Schirmer, G. Schmidt, K. Wille
    DELTA, Dortmund
  A new beam based method is introduced to measure the transversal shifts of quadrupole magnets in relation to each other within triplet structures. The displacements of the quadrupole magnets can be calculated by quadrupole strength variation in combination with a simulation of the orbit distortions utilizing a MATLAB based model for beam optics. A local smoothing of the quadrupole alignment can be achieved with accuracy better than those of geodetic surveys. Results are presented and compared with data from geodetic surveys.  
 
TUPC122 Feedback Corrections for Ground Motion Effects at ATF2 sextupole, feedback, quadrupole, coupling 1353
 
  • Y. Renier, P. Bambade
    LAL, Orsay
  Ground motion will over time produce beam misalignments and size increases at the IP of the ATF2 beam line. The spatial and temporal characteristics of the vibrations measured on the site have been studied and model parameters have been fitted to allow reliably simulating the effects induced on the beam. A feedback loop to minimise the residual beam motion at the IP is considered, based on optimising the coefficients of a PID controller on both short and long time-scales.  
 
TUPD031 Crystals Application in the TOTEM Experiment to Increase the Acceptance of a Roman Pot proton, scattering, simulation, closed-orbit 1491
 
  • E. Laface, W. Scandale
    CERN, Geneva
  • S. Hasan
    Univ. Insubria and INFN Milano, Como
  • C. Santoni
    Université Blaise Pascal, Clermont-Ferrand
  Bent crystal may enhance the physics reach of a near-beam physics detector in the CERN-LHC, by increasing the acceptance of scattered protons in low transverse momentum reactions. As an example we present simulations demonstrating the increase of the Roman Pot acceptance in the TOTME apparatus. Starting from the MadX v6.5 nominal optic, a crystal is placed at different longitudinal and transversal positions: for each scheme a gaussian beam of protons with different kinematic variables is created and tracked along the optical line with crystal. The number of protons with transversal coordinates greater than 10σ+0.5mm, that is inside the Roman Pot, is compared with the total number of protons. The possible gain in acceptance is around 15-20%.  
 
TUPP005 Application Programs for the Elettra Booster Commissioning and Operation booster, controls, lattice, power-supply 1535
 
  • F. Iazzourene, V. Forchi', C. Scafuri
    ELETTRA, Basovizza, Trieste
  The application programs developed for the commissioning and operation of the new Elettra injector* are all based on the TANGO control system, a new high level framework and a beam optics module named Vicky**. The present paper summarizes the main developed application programs and their successful use during commissioning and operation of the new injector.

*"Overview of the Status of the Elettra Booster Project," these proceedings.
**"Elettra New Full Injector High Level Software," C. Scafuri, F. Iazzourene, EPAC 2006.

 
 
TUPP017 Orbit and Dispersion Tool at FLASH controls, undulator, electron, quadrupole 1565
 
  • E. Prat, V. Balandin, N. Golubeva
    DESY, Hamburg
  • J. K. Kamenik, I. Kriznar, T. Kusterle
    Cosylab, Ljubljana
  Based on a former MATLAB tool, a java-based application to measure and correct orbit and dispersion has been developed at FLASH. In this paper we discuss the algorithm used in this tool as well as its functionality. First tests on machine operation are also presented.  
 
TUPP079 Distortion of Crabbed Bunch due to Electron Cloud with Global Crab electron, betatron, luminosity, positron 1715
 
  • L. Wang, Y. Cai, T. O. Raubenheimer
    SLAC, Menlo Park, California
  In order to improve the luminosity, crab cavities have been installed in the KEKB HER and LER. Since there is only one crab cavity in each ring, the crab cavity generates a horizontally titled bunch oscillating around the whole ring. The electron cloud in LER (positron beam) may distort the crabbed bunch and cause the luminosity drop. This paper briefly estimates the distortion of positron bunch due to the electron cloud with global crab.  
 
TUPP091 WISE: a Simulation of the LHC Optics Including Magnet Geometrical Data alignment, simulation, injection, lattice 1744
 
  • P. Hagen, M. Giovannozzi, J.-P. Koutchouk, T. Risselada, F. Schmidt, E. Todesco, E. Y. Wildner
    CERN, Geneva
  The beam dynamics in LHC strongly depends on the field quality and geometry of the magnets. A model of the LHC optics has been built, based on the information available at the end of the production as well as on statistical evaluations for the missing information The pre-processor WISE generates instances of the LHC field errors for the MAD X program, with the possibility of selecting various sources. This paper describes the progress since WISE was presented in EPAC06. The slot allocation in LHC is completed since all magnets are installed and interconnected. Geometric measurements have been added for all magnets. Furthermore, some statistical data is available relative to the precision of magnet installation (alignment) and tunnel movements. In this paper the code and the data are used to update the beta-beating estimate at injection and collision energy. The relevance of misalignments of the different magnets and their impact on beta-beating is compared to the sources that have been previously considered, i.e. the spread in the gradient of the cell quadrupoles and the uncertainty associated to the knowledge of the transfer functions of the stand-alone quadrupoles.  
 
WEZG02 Commissioning of an Accelerator: Tools and Management controls, synchrotron, storage-ring, diagnostics 1926
 
  • A. Nadji
    SOLEIL, Gif-sur-Yvette
  During the life of an accelerator project, the commissioning is a very important and exciting phase. It is preceded by a long period of design, calculations, magnetic measurements, installation, and alignment. We want the commissioning stage to be successful and fast; that is, attaining rapidly the set goals and make the machine available for impatient users. This paper summarizes the experience of several commissioning phases for different types of accelerators such as SNS, JPARC, and LHC, as well as synchrotron light sources such as DIAMOND, SOLEIL, and SSRF. The importance of preparation for commissioning on both technical and personnel levels will be covered. We will also talk about the concept of stages, anticipation of problems, and the early involvement of many specialists in addition to accelerator physicists and future accelerator operators. Furthermore, we will outline the importance of having a command control that is practical, fast, and has the capacity to offer high level automated applications. Finally, we will discuss the indispensable role of diagnostics for the first injection and first turns of the beam.  
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WEPC024 Low Beta Structure for the ANKA Storage Ring dynamic-aperture, emittance, vacuum, injection 2034
 
  • E. Huttel, I. Birkel, A.-S. Müller, P. Wesolowski
    FZK, Karlsruhe
  The ANKA storage ring has a fourfold symmetry with a double DBA structure. Four (~1.7 m) straight sections are used for the RF and the injection. Four sections (~ 4.5 m) are used for insertion devices (three installed). The beta functions in these sections are 14, respectively 7 m (horizontal/vertical). This is not ideal for small gap (7 mm) insertion devices. Reducing the vertical beta function to 2 m is possible with the present magnet configuration and is done for special user operation. Reducing both the horizontal and vertical beta function is favoured for one future beam line. This will afford a change of the present magnet configuration. Different options have been calculated and will be discussed.  
 
WEPC042 Commissioning of the SSRF Storage Ring storage-ring, closed-orbit, emittance, sextupole 2079
 
  • L. G. Liu
    SSRF, Shanghai
  • Z. M. Dai, B. C. Jiang, H. H. Li, D. Wang, W. Zhang, Z. T. Zhao
    SINAP, Shanghai
  The Shanghai Synchrotron Radiation Facility (SSRF) is a 3.5GeV synchrotron radiation light source under commissioning in Shanghai, China. The SSRF accelerator complex consists of a 150MeV linac, full energy booster and a 3.5GeV storage ring. The commissioning of the SSRF storage ring began on Dec. 21st evening, 2007, the first turn and 150 turns was observed in less than 12 hours with RF off and then the stored beam of 5 mA was achieved on Dec. 24th. On Jan. 3rd, 2008, the 100mA stored beam current were obtained in the machine for the first time. Since then, the storage ring has been brought close to the design parameters, and frequent operation with 100mA beam current has been down for making the vacuum chamber cleaning. In this paper, commissioning results of the machine is presented.  
 
WEPC045 Alternative Lattice Settings for ALBA Storage Ring sextupole, lattice, dynamic-aperture, resonance 2088
 
  • M. Munoz, G. Benedetti, D. Einfeld, Z. Martí
    ALBA, Bellaterra
  ALBA is a 3 GeV synchrotron light source under construction in Spain. The lattice for the standard operational mode is based in a DBA-like structure, with finite dispersion in the straight sections and extra space in the arcs. This solution provides small emittance with a large available space for insertion devices, RF and diagnostic components, and large dynamic aperture and energy acceptance. Other optic modes has been investigated, in order to facilitate the commissioning procedure or to provide different operating modes to the users: pure achromatic lattice, without dispersion in the straight section; achromatic arcs, where the dispersion is zero in the long straight; or a relaxed lattice, offering higher emittance. This paper review the performance of this alternative options, including the non-linear performance.  
 
WEPC056 Emittance Reduction by Longitudinally Varying Dipole Field emittance, dipole, dynamic-aperture, radiation 2118
 
  • K. Tsumaki
    JASRI/SPring-8, Hyogo-ken
  One of the most important matters for synchrotron radiation source is decreasing the beam emittance to increase the brightness. The electron beam emittance is almost determined by electron energy and the average H-function. For further improvement of the emittance, we can change the damping partition number by radially varying dipole field and can reduce the emittance. However, this method is not effective for a small emittance lattice due to its small dispersion function. We have studied the emittance reduction by longitudinally varying magnetic field in a bending magnet. The radius of curvature is assumed to vary with the function of nth degree (n=1,2,3,4). The emittance is calculated numerically for minimum emittance and achromat configuration. In this paper, we describe the details of calculated results and discuss the effectiveness of the method.  
 
WEPC079 Elettra Booster Commissioning and Operation booster, injection, storage-ring, emittance 2180
 
  • F. Iazzourene
    ELETTRA, Basovizza, Trieste
  The new injector, consisting of a 100MeV linac and a 2.5GeV booster synchrotron, replaced the old limited energy 1.2GeV linac by the end of 2007*. The paper reports on its commissioning phases and results together with its present status of operation.

*"Overview of the Status of the Elettra Booster Project", WEPC090, these proceedings.

 
 
WEPD023 Multi-purpose Fiber Optic Sensors for HTS Magnets superconducting-magnet, monitoring, controls, background 2458
 
  • J. Schwartz
    NHMFL, Tallahassee, Florida
  • R. P. Johnson, S. A. Kahn, M. Kuchnir
    Muons, Inc, Batavia
  Magnets using new high temperature superconductor (HTS) materials are showing great promise for high magnetic field and/or radiation environment applications such as particle accelerators, NMR, and the plasma-confinement systems for fusion reactors. The development and operation of these magnets is limited, however, because appropriate sensors and diagnostic systems are not yet available to monitor the manufacturing and operational processes that dictate success. Optical fibers are being developed to be imbedded within the HTS magnets to monitor strain, temperature and irradiation, and to detect quenches. In the case of Bi2212, the fiber will be used as a heat treatment process monitor to ensure that the entire magnet has reached thermal equilibrium. Real-time measurements will aid the development of high-field magnets that are subject to large Lorentz forces and allow the effective detection of quenches so that the stored energy of operating magnets can be extracted and/or dissipated without damaging the magnet.  
 
WEPD037 Nb3Sn Quadrupoles in the LHC IR Phase I Upgrade quadrupole, luminosity, dipole, coupling 2491
 
  • A. V. Zlobin, J. A. Johnstone, V. Kashikhin, N. V. Mokhov, I. L. Rakhno
    Fermilab, Batavia, Illinois
  • S. Peggs, G. Robert-Demolaize, P. Wanderer, R. de Maria
    BNL, Upton, Long Island, New York
  After some years of operation at nominal parameters, the LHC will be upgraded for higher luminosity. At the present time it is planned to perform the IR upgrade in two phases with the target luminosity for Phase I of ~2.5· 1034 cm-2s-1 and up to 1035 cm-2s-1 for Phase II. In Phase I the baseline 70-mm NbTi low-beta quadrupoles will nominally be replaced with larger aperture NbTi magnets and in Phase II with higher performance Nb3Sn magnets. U. S.-LARP is working on the development of large aperture high-performance Nb3Sn magnet technologies for the LHC Phase II luminosity upgrade. Recent progress also suggests the possibility of using Nb3Sn quadrupoles in the Phase I upgrade, improving the luminosity through an early demonstration of Nb3Sn magnet technology in a real accelerator environment. This paper discusses the possible hybrid optics layouts for Phase I upgrades with both NbTi and Nb3Sn quadrupoles, introducing magnet parameters and issues related to using Nb3Sn quadrupoles including magnet length and aperture limitations, field quality, operation margin, etc. Possible transition scenarios to Phase II are also discussed.  
 
WEPP003 Optics Flexibility in the LHC at Top Energy injection, quadrupole, betatron, luminosity 2524
 
  • M. Aiba, H. Burkhardt, S. D. Fartoukh, M. Giovannozzi, S. M. White
    CERN, Geneva
  We report on studies of optics flexibility which allow for tune changes of the order of half a unit at top energy in the LHC. We describe how this could be done using one or several of the insertions IR2, IR4, IR8 or the main quadrupoles and discuss and compare the implications. This flexibility could be used to compensate for the loss in tune for high beta optics and may make it feasible to use the standard injection and ramp for these configurations. Potential further applications are also highlighted.  
 
WEPP004 Overall Optics Solutions for Very High Beta in Atlas insertion, emittance, injection, luminosity 2527
 
  • S. M. White, H. Burkhardt, P. M. Puzo
    CERN, Geneva
  • S. Cavalier, M. Heller
    LAL, Orsay
  An insertion optics with a beta-star of at least 2600 m has been requested by the ATLAS experiment at the LHC. This is very far from the standard LHC physics optics and implies a significant reduction in the phase advance from this insertion corresponding to about half a unit in tune. We describe several alternatives how this could be integrated in overall LHC optics solutions with the possibility to inject, ramp and un-squeeze to the required very high beta.  
 
WEPP007 Crab Compensation for LHC Beams impedance, damping, collimation, luminosity 2536
 
  • R. Calaga
    BNL, Upton, Long Island, New York
  • Y. Sun, R. Tomas, F. Zimmermann
    CERN, Geneva
  An R&D program to establish a road map for the installation of crab cavities in the LHC is rapidly advancing. Both local and global crab schemes are under investigation to develop cavities that will be compatible with LHC optics and meet aperture requirements. The design of a prototype TM110 cavity and pertinent RF requirements including impedance estimates and damping are discussed. Some alternate cavity designs are also explored. The required optics modifications to accommodate the crab cavities and some particle stability studies are presented.  
 
WEPP012 Analysis of Optical Layouts for the Phase 1 Upgrade of the CERN Large Hadron Collider Insertion Regions insertion, quadrupole, dipole, dynamic-aperture 2551
 
  • M. Giovannozzi, F. Borgnolutti, O. S. Brüning, U. Dorda, S. D. Fartoukh, W. Herr, M. Meddahi, E. Todesco, R. Tomas, F. Zimmermann
    CERN, Geneva
  • R. de Maria
    EPFL, Lausanne
  In the framework of the studies for the upgrade of the insertions of the CERN Large Hadron Collider, four optical layouts were proposed with the aim of reducing the beta-function at the collision point down to 25 cm. The different candidate layouts are presented. Results from the studies performed on mechanical and dynamic aperture are summarized, together with the evaluation of beam-beam effects. Particular emphasis is given to the comparison of the optics performance, which led to retain two promising layouts for further investigation and development.  
 
WEPP024 Non-linear Correction Schemes for the Phase 1 LHC Insertion Region Upgrade and Dynamic Aperture Studies dynamic-aperture, resonance, quadrupole, insertion 2569
 
  • R. Tomas, M. Giovannozzi, R. de Maria
    CERN, Geneva
  The Phase 1 LHC Interaction Region (IR) upgrade aims at increasing the machine luminosity essentially by reducing the beam size at the Interaction Point (IP). This requires a total redesign of the full IR. A large set of options have been proposed with conceptually different designs. This paper reports on a general approach for the compensation of the multipolar errors of the IR magnets in the design phase. The goal is to use the same correction approach for the different designs. The correction algorithm is based on the computation of the IR transfer map. Its performance is tested using the dynamic aperture as figure of merit.  
 
WEPP025 Optics Correction in the LHC quadrupole, dipole, closed-orbit, betatron 2572
 
  • R. Tomas, M. Aiba, G. Vanbavinckhove
    CERN, Geneva
  • R. Calaga
    BNL, Upton, Long Island, New York
  • A. Morita
    KEK, Ibaraki
  Optics correction in the LHC is challenged by the tight aperture constrains and the demand of a highly performing BPM system. To guarantee that the LHC optics remains within a maximum allowable beta-beating of 20% several methods are being investigated through computer simulations and experiments at existing hadron machines. A software package to consolidate the implementation of the various techniques during LHC operation is underway (or nearing completion)  
 
WEPP037 Independent Component Analysis of Tevatron Turn-by-turn BPM Measurements betatron, synchrotron, collider, extraction 2602
 
  • A. V. Petrenko
    BINP SB RAS, Novosibirsk
  • V. A. Lebedev, A. Valishev
    Fermilab, Batavia, Illinois
  Transverse dipole coherent beam oscillations in the Tevatron were analyzed with different independent component analysis algorithms. This allowed to obtain the model-independent values of coupled beta-functions as well as betatron phase advance and dispersion along the ring from a single kick measurement. Using a 1-turn shift of turn-by-turn BPM readings for virtual doubling of the number of BPMs it is also possible to measure the fractional part of betatron tunes with high accuracy. Good agreement with the linear optical model of the Tevatron was observed.  
 
WEPP047 Optics Implications of Implementing Nb3Sn Magnets in the LHC Phase I Upgrade quadrupole, luminosity, focusing, lattice 2626
 
  • J. A. Johnstone, V. Kashikhin, N. V. Mokhov, A. V. Zlobin
    Fermilab, Batavia, Illinois
  CERN has encouraged the US-LARP collaboration to participate in Phase I of the LHC luminosity upgrade by analyzing the benefits gained by using Nb3Sn technology to replace the functionality of select magnets CERN is commited to construct using NbTi magnets. Early studies have shown that the much higher gradients (shorter magnetic lengths) and energy load of Nb3Sn magnets compared to their NbTi counterpars is very favorable – allowing the insertion of additional absorbers between Q1 & Q2, for example. This paper discusses the relative merits of the NbTi and Nb3Sn options.  
 
WEPP048 Recirculating Linear Muon Accelerator with Ramped Quadrupoles linac, focusing, quadrupole, acceleration 2629
 
  • S. A. Bogacz
    Jefferson Lab, Newport News, Virginia
  • R. P. Johnson
    Muons, Inc, Batavia
  Neutrino Factories and Muon Colliders require rapid acceleration of short-lived muons to multi-GeV and TeV energies. A Recirculating Linear Accelerator (RLA) that uses a single Linac and teardrop return arcs can provide exceptionally fast and economical acceleration to the extent that the focusing range of the RLA quadrupoles allows each muon to pass several times through each high-gradient cavity. A new concept of rapidly changing the strength of the RLA focusing quadrupoles as the muons gain energy is being developed to increase the number of passes that each muon will make in the RF cavities, leading to greater cost effectiveness. We are developing the optics and technical requirements for RLA designs, using RF cavities capable of simultaneous acceleration of both μ+ and μ- species, with pulsed Linac quadrupoles to allow the maximum number of passes.

Supported in part by DOE STTR grant DE-FG02-05ER86253

 
 
WEPP049 Advances on ELIC Design Studies electron, ion, luminosity, collider 2632
 
  • S. A. Bogacz, P. Chevtsov, Y. S. Derbenev, P. Evtushenko, M. Hutton, G. A. Krafft, R. Li, L. Merminga, J. Musson, B. C. Yunn, Y. Zhang
    Jefferson Lab, Newport News, Virginia
  • J. Qiang
    LBNL, Berkeley, California
  • H. K. Sayed
    Old Dominion University, Norfolk, Virginia
  An electron-ion collider of a center-of-mass energy up to 90 GeV at luminosity up to 1035 cm-2s-1 with both beams highly polarized is essential for exploring the new QCD frontier of strong color fields in nuclear and precisely imaging the sea-quarks and gluons in the nucleon. A conceptual design of a ring-ring collider based on CEBAF (ELIC) with energies up to 9 GeV for electrons/positrons and up to 225 GeV for protons and 100 GeV/u for ions has been proposed to fulfill the science desire and to serve as the next step for CEBAF after the planned 12 GeV energy upgrade of the fixed target program. Here, we summarize recent design progress for the ELIC complex with four interaction points (IP); including interaction region optics with chromatic aberration compensation scheme and complete lattices for the Figure-8 collider rings. Further optimization of crab crossing angles at the IPs, simulations of beam-beam interactions and electron polarization in the Figure-8 ring and its matching at the IPs are also discussed.  
 
WEPP052 A Storage Ring Based Option for the LHeC lepton, hadron, proton, electron 2638
 
  • F. J. Willeke
    BNL, Upton, New York
  • F. Bordry, H.-H. Braun, O. S. Brüning, H. Burkhardt, J. M. Jowett, T. P.R. Linnecar, K. H. Mess, S. Myers, J. A. Osborne, F. Zimmermann
    CERN, Geneva
  • S. Chattopadhyay
    Cockcroft Institute, Warrington, Cheshire
  • J. B. Dainton, M. Klein
    Liverpool University, Science Faculty, Liverpool
  • B. J. Holzer
    DESY, Hamburg
  The LHeC aims at the generation of Hadron-Lepton collisions with center of mass energies in the TeV scale and luminosities of the order of 1033 cm-2 sec-1 by taking advantage of the existing LHC 7 TeV proton ring and adding a high energy electron accelerator. This paper presents technical considerations and potential parameter choices for such a machine and outlines some of the challenges arising when an electron storage ring based option, constructed within the existing infrastructure of the LHC, is chosen.  
 
WEPP057 Fitting Algorithms for Optical and Beam Parameters in Transfer Lines with Application to the LHC Injection Line TI2 emittance, extraction, quadrupole, injection 2647
 
  • E. Benedetto, I. V. Agapov, F. Follin, V. Kain
    CERN, Geneva
  As part of the commissioning with beam of the transfer line TI2 from the SPS to the LHC, a series of optics measurements has been conducted. The paper presents the results in terms of Twiss parameters (including the dispersion), emittance and momentum spread obtained from the combination of trajectory and beam profile measurements. Profiting from the redundancy of monitors, there is a possibility of applying different fitting algorithms to retrieve beam parameters and to extract information on the optics of the line. The results from the different fit methods applied to the data will be compared with the expected values and cross-checked with independent measurements with a particular emphasis on the error analysis.  
 
WEPP058 Optics Measurements and Matching of TT2-TT10 Line for Injection of the LHC Beam in the SPS injection, scattering, emittance, betatron 2650
 
  • E. Benedetto, G. Arduini, A. Guerrero, D. Jacquet
    CERN, Geneva
  A well matched injection in the SPS is very important for preserving the emittance of the LHC beam. The paper presents the algorithms used for the analysis and the results of the optics measurements done in the transfer line TT2-TT10 and in the SPS. The dispersion is computed by varying the beam momentum and recording the offsets at the BPMs, while the Twiss parameters and emittance measurements in TT2-TT10 are performed with beam profile monitors equipped with OTR screens. These results are completed by those obtained with a matching monitor installed in the SPS as a prototype for the LHC. This device makes use of an OTR screen and a fast acquisition system, to get the turn by turn beam profiles right at injection in the ring, from which the beam mismatch is computed and compared with the results obtained in the line. Finally, on the basis of such measurments, a betatron and dispersion matching of TT2-TT10 for injection in the SPS has been performed and successfully put in operation.  
 
WEPP063 R-matrices of the Fast Beam Extraction Section of AGS extraction, kicker, quadrupole, synchrotron 2662
 
  • N. Tsoupas, L. Ahrens, J. W. Glenn, W. W. MacKay, T. Satogata
    BNL, Upton, Long Island, New York
  The Fast Beam Extraction (FEB) system of the Alternating Gradient synchrotron (AGS) extracts the beam bunches from AGS into the AGS-to-RHIC (AtR) beam transfer line, and the extracted bunches are injected into the Relativistic Heavy Ion Collider (RHIC) synchrotron. In a particular section of the beam extraction line the beam bunches are transported through the fringe field region of three main AGS magnets. Optical characteristics of this section change with trajectory and momentum. Therefore the calculation of the R-matrices in this part of the extraction line requires special attention. To describe accurately the R-matrices, the magnetic field of the AGS main magnets was measured on the median plane of the AGS magnet in both, the circulating beam region and the fringe field region, where the extracted beam is transported. Using these magnetic field maps we describe the procedure we use to calculate the R-matrices at the beam extraction region. These R-matrices are used to calculate the beam parameters at the starting point of the AtR beam transfer line and the required quadrupole settings to match to RHIC’s acceptance.  
 
WEPP065 Beam Commissioning of the SPS-to-LHC Transfer Line TI 2 extraction, radiation, proton, controls 2668
 
  • J. A. Uythoven, G. Arduini, R. W. Assmann, N. Gilbert, B. Goddard, V. Kain, A. Koschik, T. Kramer, M. Lamont, V. Mertens, S. Redaelli, J. Wenninger
    CERN, Geneva
  The transfer line for the LHC Ring 1 was successfully commissioned with beam in the autumn of 2007. After extraction from the SPS accelerator and about 2.7 km of new transfer line, the beam arrived at the temporarily installed beam dump, about 50 m before the start of the LHC tunnel, without the need of any beam threading. This paper gives an overview of the hardware commissioning period and the actual beam tests carried out. It summarises the results of the beam test optics measurements and the performance of the installed hardware.  
 
WEPP087 Observation and Mitigation of Multipass BBU in CEBAF linac, dipole, damping, recirculation 2722
 
  • R. Kazimi, A. Freyberger, C. Hovater, G. A. Krafft, F. Marhauser, T. E. Plawski, C. E. Reece, J. S. Sekutowicz, C. Tennant, M. G. Tiefenback, H. Wang
    Jefferson Lab, Newport News, Virginia
  The CEBAF recirculating accelerator at Jefferson Lab consists of two linacs carrying beam for up to five passes of acceleration. The Beam Break-Up (BBU) phenomenon was anticipated during design of the accelerator. The threshold beam current to induce BBU was calculated to be approximately 20 milliamperes, far above operational current. No sign of BBU was ever seen in more than a decade of operation. A specially designed acceleration cavity in a recently installed cryomodule was found to cause a BBU instability under special conditions with as low as 40 uA of injected beam current. This presented an opportunity to study BBU in a five-pass accelerator. In this paper we will discuss multipass BBU, show observational data, and discuss the ways we have developed to maintain the instability threshold current to values above those required for operation.  
 
WEPP108 The MICE Diffuser System emittance, controls, dipole, target 2761
 
  • M. Apollonio, J. H. Cobb, T. Handford, P. Lau, W. Lau, J. Tacon, M. Tacon, S. Q. Yang
    OXFORDphysics, Oxford, Oxon
  • M. Dawson
    JAI, Oxford
  The MICE experiment at RAL will measure the performance of a cooling channel in a variety of configurations of momentum and initial emittance. Coverage in phase space relies on the MICE diffuser, a system with five different thickness lead degraders, remotely operated in a high magnetic field. Technical issues and degrader optimisation for beam matching are discussed.  
 
WEPP157 Lithium Lens for Positron Production System positron, target, focusing, undulator 2856
 
  • A. A. Mikhailichenko
    Cornell University, Department of Physics, Ithaca, New York
  We represent optimized parameters for undulator-based positron production scheme for ILC-type machine. In particular we describe details of Lithium lens design suggested for usage in collection optics.  
 
THPC016 Beam Optics of the PEFP Modified Beam Lines proton, quadrupole, dipole, linac 3011
 
  • J.-H. Jang, Y.-S. Cho, B. Chung, H.-J. Kwon
    KAERI, Daejon
  The 100 MeV Linac of the Proton Engineering Frontier Project (PEFP) is designed to supply 20 MeV and 100 MeV proton beams to user groups. In order to extract 20 MeV proton beams, a 45 degrees bending magnet is installed after 20 MeV DTL tank. The extracted proton beams are separated into five target rooms via a AC bending magnets. For 100 MeV beams, we use the same distribution schemes. Recently, the layout of the beam lines are modified to be short and compact. The work summaries the beam optics calculation of the modified beam lines.  
 
THPC017 Optimisation of a Beam Transfer FODO Line quadrupole, vacuum, emittance, beam-losses 3014
 
  • J. B. Jeanneret, H.-H. Braun
    CERN, Geneva
  With in view the design of the CLIC long transfer lines, we developed a formal approach for the optimisation of a straight FODO line. Optimum phase advance and cell length depending on beam parameters are derived for power consumption, overall cost and sensitivity to quadrupole misalignment.  
 
THPC020 Emittance Exchange at the Fermilab A0 Photoinjector emittance, diagnostics, electron, controls 3020
 
  • T. W. Koeth
    Rutgers University, The State University of New Jersey, Piscataway, New Jersey
  • L. Bellantoni, H. T. Edwards, R. P. Fliller, A. H. Lumpkin, J. Ruan
    Fermilab, Batavia, Illinois
  A transverse to longitudinal emittance exchange experiment is underway at the A0 Photoinjector at Fermilab. Our scheme employs a TM110 deflecting mode RF cavity between two magnetic doglegs proposed by Kim et. al. The beamline has been installed, characterization of the beamline is complete and data taking has begun. In this paper we report on efforts to date to observe the transverse to longitudinal emittance exchange. Measurements will be compared to analytical predictions and simulations.  
 
THPC021 Investigations on a Q0 Doublet Optics for the LHC Luminosity Upgrade quadrupole, luminosity, closed-orbit, alignment 3023
 
  • E. Laface, W. Scandale, E. Y. Wildner
    CERN, Geneva
  • C. Santoni
    Université Blaise Pascal, Clermont-Ferrand
  The Q0 scheme of the LHC insertion region is based on the introduction of a doublet of quadrupoles at 13 meters from IP. We present here the doublet optics and the magnets layout such as gradients, lengths, positions and apertures. In this scheme we show the gain in luminosity and chromaticity, with respect to a nominal layout with β*=0.25 (i.e. LHC phase 1 upgrade) and β*=0.15 m, due to a smaller beta-max. We show the alignment tolerance and the energy deposition issues, in Q0A-Q0B. We also consider shielding the magnets with liners. The capability of Q0 optics to limit the β function could be exploited after the LHC Phase 1 upgrade in order to reduce the β* below 0.25 m, leaving the upgraded triplet unchanged.  
 
THPC024 Closed Orbit Correction at the LNLS UVX Storage Ring coupling, sextupole, storage-ring, feedback 3029
 
  • L. Liu, R. H.A. Farias, X. R. Resende, P. F. Tavares
    LNLS, Campinas
  The orbit correction of stored electrons in the LNLS storage ring often needs a few iterations to converge to the smallest distortion. This is caused in part by the residual coupling between transverse planes. This coupling effect can be included in the correction algorithm leading to the best orbit in just one iteration. However, in the LNLS ring, the number of monitors equals the number of vertical correctors but surpasses the number of horizontal correctors. This means that the vertical orbit can be corrected to zero at the position monitors in the decoupled situation but the horizontal orbit cannot. For the coupled case, the incapacity of zeroing the horizontal orbit leaks into the vertical plane. This problem can be addressed by the eigenvector method with constraints.  
 
THPC032 Vertical Beam Size Reduction via Compensation of Residual Transverse Coupling coupling, wiggler, simulation, closed-orbit 3047
 
  • T. F. Roque, X. R. Resende, P. F. Tavares
    LNLS, Campinas
  The Brazilian Synchrotron Light Source (LNLS) is currently constructing a beamline which will make use of the radiation produced by the EPU installed in the storage ring (SR) in 2007. Various force tasks have been triggered by this new beamline in order to achieve required beam properties and stability. One of these tasks has to do with reducing the SR's vertical beam size at the straight section where the EPU is located, hence improving the radiation brilliance from the EPU. This report will describe our recent efforts in understanding and controlling what residual effects there are in the ring that dominate the ring's vertical beam size. In particular, we study the effects of residual coupling perturbations on the beam size through the transfer matrix formalism which, we argue, is the most appropriate. A beam model including transverse linear coupling is validated with measured closed orbit response functions. By Analyzing this model we are able to propose new skew quadrupole elements to the SR that might reduce the vertical beam size at the EPU section and we can infer the validity of results with a pinhole beam imaging system which we have available in our diagnostic beamline.  
 
THPC048 Study of Beam Losses at Transition Crossing at the CERN PS quadrupole, beam-losses, proton, dipole 3086
 
  • S. S. Gilardoni, S. Aumon, M. Martini
    CERN, Geneva
  A series of studies has been carried out to understand and alleviate the beam losses in the CERN PS proton Synchrotron. In particular, losses appear at transition crossing during the pulsing of special quadrupoles used to create a gamma jump scheme and which causes a large optics and orbit distortion. After a brief summary of the gamma jump scheme at the PS, experimental and simulation results about the loss studies and reduction are presented.  
 
THPC053 Turn-by-turn Data Analysis at the Diamond Storage Ring betatron, storage-ring, resonance, quadrupole 3101
 
  • R. Bartolini, I. P.S. Martin, G. Rehm, J. Rowland
    Diamond, Oxfordshire
  The Diamond Storage Ring has been recently equipped with a set of two pinger magnets that can excite betatron oscillations to large amplitudes in both planes of motion. In conjunction with the turn-by-turn capabilities available at all BPMs, the system provides a powerful diagnostic tools for the characterisation of the linear and non-linear beam dynamics of the electron beam in the storage ring. We report the first results on the application of the Frequency Map Analysis and the measurement of the resonant driving terms at the Diamond Storage Ring.  
 
THPC064 Use of LOCO at Synchrotron SOLEIL lattice, storage-ring, quadrupole, coupling 3131
 
  • L. S. Nadolski
    SOLEIL, Gif-sur-Yvette
  SOLEIL is a 354 m long 2.75 GeV third generation synchrotron light source delivering photons to beam-lines since January 2007. This paper will discuss in details the first attempts using LOCO code and problems encountered due to the storage ring lattice compactness. The introduction into the code of constraints on the quadrupole gradient variations gave tremendous improvements. The convergence is satisfactory, beta –beatings are reduced from 5% to below 1% RMS in both planes. Restoring the symmetry of the lattice enhanced the performances of the storage ring. In the last part, different ways of using LOCO as a powerful diagnostics tool will be given.  
 
THPC072 Impact of Betatron Motion on Path Lengthening and Momentum Aperture in a Storage Ring betatron, storage-ring, resonance, undulator 3152
 
  • M. Takao
    JASRI/SPring-8, Hyogo-ken
  The amplitude of the betatron motion in an electron storage ring becomes large in some cases, e.g. Touschek scattered electrons or injected beam. Then we cannot ignore the effect of a finite amplitude of betatron motion on the beam dynamics. The path lengthening of the central trajectory of betatron motion is one of the most serious manifestations of such an influence. Due to the synchrotron motion, the variation of the path length is converted into the energy deviation, so that the betatron motion gives the impact on the momentum aperture in the storage ring. In this paper the path lengthening by a finite amplitude betatron motion is calculated by means of the canonical perturbation method. The derived formula for the path lengthening is simply represented by the product of the chromaticity and the invariant amplitude. Using the formula, we discuss the impact of the betatron motion on momentum aperture in a Touschek effect.  
 
THPC082 Wire Excitation Experiments in the CERN SPS simulation, beam-losses, coupling, resonance 3176
 
  • U. Dorda, J.-P. Koutchouk, R. Tomas, J. Wenninger, F. Zimmermann
    CERN, Geneva
  • R. Calaga, W. Fischer
    BNL, Upton, Long Island, New York
  In order to study the effect of long range interaction and its wire compensation experimentally, current carrying wires are installed in the CERN Super Proton Synchrotron (SPS). In this paper we summarize the main results of the 2007 wire excitation results at 26, 37 and 55 GeV including wire-current-, beam-wire distance and chromaticity scans. A strong dependence on the chromaticity and indications of a threshold effect at 37 and 55 GeV was found. The results are compared to simulation, to a simple analytic scaling law and to experimental results from RHIC. Wire-driven resonances have been observed through the Fourier spectrum of experimental BPM data and compared to simulations.  
 
THPP089 Gamma Transition Jump for PS2 betatron, quadrupole, collective-effects, lattice 3572
 
  • W. Bartmann, M. Benedikt, E. Métral, D. Möhl
    CERN, Geneva
  • S. Peggs
    BNL, Upton, Long Island, New York
  The PS2, which is proposed as a replacement for the existing ~50-year old PS accelerator, is presently considered to be a normal conducting synchrotron with an injection kinetic energy of 4 GeV and a maximum energy of 50 GeV. One of the possible lattices (FODO option) foresees crossing of transition energy near 10 GeV. Since many intensity dependent effects can take place in both the longitudinal and the transverse planes a fast jump of gamma transition is necessary in order to pass the non-adiabatic region rapidly. The aim of the present paper is on the one hand to scale the gamma transition jump, used since 1973 in the PS, to the projected PS2 and on the other hand based on these results the analysis of the implementation and feasibility of a gamma transition jump scheme in a conventional FODO lattice.  
 
THPP101 Investigation of Lifetime of the Electronics and the Fiber Optics inside the Niche and the Tunnel in the Slow Extraction Area of SIS100 extraction, ion, simulation, antiproton 3599
 
  • A. B. Plotnikov, E. Mustafin, N. Pyka, P. J. Spiller
    GSI, Darmstadt
  The loss of ions in the slow extraction area of the SIS100 accelerator project at FAIR can be dangerous for the electronic equipment and fiber optics situated inside the tunnel and niches around. During the slow extraction lost ions irradiate the yoke of the quadrupole magnets and collimator and produce a neutrons flux, which can damage or make single event upset at the electronic devices. Also fiber optic cores fade under the action of irradiation. In the current work the investigation of the dose distribution and neutron fluxes, as well as the calculation of the lifetime of the electronics and fiber optics in different places of the tunnel have been done. By using these results the design of the niches and shielding is planned.