EPAC 2006 - Classification:05 Beam Dynamics and Electromagnetic Fields/D01 Beam Optics

05 Beam Dynamics and Electromagnetic Fields

D01 Beam Optics - Lattices, Correction Schemes, Transport

Paper	Title	Page
WEPCH004	Estimation of Transverse Coupling From Pinhole Images	1921
	X.R. Resende, P.F. Tavares LNLS, Campinas
	The Brazilian Synchrotron Light Laboratory (LNLS) has recently started filling its storage ring straight sections with insertion devices. Last year a 2-Tesla Wiggler was successfully installed and integrated in the control system. An elliptically polarizing undulator is now under construction and scheduled to be installed in the next shutdown, by the end of the current year. The VUV beamline for the undulator is very demanding with respect to orbit stability and other beam parameters. Considerable reduction of the vertical emittance via reduction of the transverse coupling is a must in order for the undulator beamline to achieve its promised outstanding performance. In this paper we report on recent efforts to better understand the residual coupling in the machine and we describe preliminary proposals of viable solutions that aim at controlling the linear coupling within beamline specifications.
WEPCH005	Advances in Beam Orbit Stability at the LNLS Electron Storage Ring	1924
	L. Liu, R.H.A. Farias, M.J. Ferreira, S.R. Marques, F. Rodrigues, P.F. Tavares, R.P.C.C. Tenca LNLS, Campinas
	We describe recent efforts made at the Brazilian Synchrotron Light Source (LNLS) to improve beam orbit stability. The main driving force is the high positional stability required by some specific experiments and particularly by a high resolution undulator beamline which is being built at LNLS. Recent steps taken to improve orbit stability include the development of x-ray BPMs to measure the vertical position of the x-ray beam, analysis of RF BPM movement due to thermal load induced by synchrotron radiation after injection, new algorithms to deal with BPM electronics or control board false readings and revision and modification of their installations. In addition a weighted least squares method was developed to account for global correction while simultaneously privileging some local source point position. These upgrades are part of an ongoing work to improve beam orbit stability at LNLS.
WEPCH006	Comparison between Simulations and Measurements of Low Charge Electron Bunch in the ELSA Facility	1927
	J.-L. Lemaire, A.B. Binet, A.B. Bloquet, D. Guilhem, V. Le Flanchec, S. Pichon CEA, Bruyeres-le-Chatel
	Dedicated focal spot size measurements carried out at the ELSA electron linear accelerator facility have provided detailed data which are suitable for benchmarking of different simulation codes for high charge bunch beam acceleration issued from an RF photo-injector source. We present some characteristic features of bunched electron beam propagation from beam formation at the photo-cathode to acceleration through RF cavities until the final focussing on a target, by using numerical simulations obtained with MAGIC, PARMELA, MAFIA, PARTRAN tool box codes. The challenges for the planned benchmarking are discussed.
WEPCH007	Beam Dynamics Studies for the Spiral-2 Project	1930
	J.-L. Biarrotte IPN, Orsay P. Bertrand GANIL, Caen D. Uriot CEA, Gif-sur-Yvette
	The SPIRAL-2 superconducting linac driver, which aims to deliver 5 mA, 20 A.MeV deuterons and 1 mA, 14.5 A.MeV q/A=1/3 heavy ions, is now entering the construction phase. It is composed of an injector composed of two ECR sources entering a 88 MHz RFQ, followed by a superconducting section based on independently phased quarter-wave cavities with warm focusing. This paper presents the status of the beam dynamics studies recently performed during this construction phase: consolidation and freezing of the linac design, update of the mass separation system or analysis of the proton capability.
WEPCH008	The Beta-beam Decay Ring Design	1933
	A. Chancé, J. Payet CEA, Gif-sur-Yvette
	The aim of the beta-beams is to produce highly energetic beams of pure electron neutrino and anti-neutrino, coming from beta radioactive decays of the 18Ne¹⁰⁺ and 6He²⁺, both at gamma = 100, directed towards experimental halls situated in the Frejus tunnel. The high intensity ion beams are stored in a ring until the ions decay. Consequently, all the injected particles will be lost anywhere in the ring, generating a high level of losses. The ring circumference has to be a multiple of the SPS circumference. The straight sections must be as long as possible in order to maximize the useful neutrino flux. The straight section length is chosen to be about 35% of the circumference length, which gives 1-km-long arcs. The bend field in the arcs is then reasonable. The arc has been chosen as a 2Pi phase advance insertion, which improves the optical properties (dynamic aperture and momentum acceptance) and allows the easy determination of the working point by the optics of the straight sections.
WEPCH009	Loss Management in the Beta-beam Decay Ring	1936
	A. Chancé, J. Payet CEA, Gif-sur-Yvette
	The aim of the beta-beams is to produce pure electronic neutrino and anti-neutrino highly energetic beams, coming from beta radioactive disintegration of the 18Ne¹⁰⁺ and 6He²⁺, both at gamma = 100, directed towards experimental halls situated in the Frijus tunnel. The high intensity ion beams are stored in a ring, until the ions decay. Consequently, all the injected particles will be lost anywhere around the ring generating a high level of losses. In order to keep a constant neutrino flux, the losses due to the decay of the radioactive ions are compensated with regular injections. The new ion beam is then merged with the stored beam with a specific RF program Two sources of losses have been considered: -The beta-decay products: their magnetic rigidity being different from the reference one, they are bent differently and lost. -The losses during the injection merging process. The first one needs a particular ring design in order to insert appropriate beam stoppers at the right place. The second one needs a specific collimation system which allows beam longitudinal halo cleaning between two successive injections.
WEPCH010	Beam-based Alignment for the Storage Ring Multipoles of Synchrotron SOLEIL	1939
	A. Madur, P. Brunelle, A. Nadji, L.S. Nadolski SOLEIL, Gif-sur-Yvette
	First beam-based alignment (BBA) measurements will be carried out during the commissioning of the SOLEIL Storage Ring that will start in April 2006. The results will allow calibrating the zero reading of the 120 Beam Position Monitors (BPMs) with respect to the magnetic centre of the adjacent quadrupoles or sextupoles. BPMs being either adjacent to quadrupoles or sextupoles, we plan to resort to two different BBA methods related to each multipolar magnet. Moreover, as some BPMs are located near both quadrupole and sextupole, the use of both methods will allow us to cross-check the results. We will present here the first results and the comparison with the positions of the magnetic centres as obtained from the magnetic measurements.
WEPCH011	Optimisation of a New Lattice for the ESRF Storage Ring	1942
	A. Ropert, L. Farvacque ESRF, Grenoble
	The installation of canted undulators in some of the straight sections of the ESRF storage ring is envisaged in the future. In order to free maximum space in the straight sections and minimise the reduction in length of the undulators, a new lattice, in which the straight section quadrupole triplets are replaced by doublets, is being studied. The paper describes the main features of the lattice and presents the experimental results achieved so far.
WEPCH012	Comparison of Betatron Function Measurement Methods and Consideration of Hysteresis Effects	1945
	O. Kopitetzki, D. Schirmer, G. Schmidt, K. Wille DELTA, Dortmund
	Two methods for determining the betatron functions in a storage ring were used to survey the linear optics at Delta. The fast orbit response analysis is used to gain betatron functions at the beam position monitors (BPMs) and dipole correctors. These are compared to betatron functions measured by the tune scan method which gives the beta functions in the quadrupoles. To improve the accuracy of the betatron functions obtained by the tune scan method a measuring procedure is introduced which considers the hysteresis effects in the quadrupole magnets. Systematic deviations in the beta functions measured between the two methods have been observed. The calibration errors of the BPMs can explain the observed deviations. With the orbit response analysis also the betatron phase advances between the measurement points can be calculated. Because these do not depend on the calibration errors, unlike the betatron functions, the differences between measurement and model can be determined more precise. A comparison of both methods with the optics model will be presented.
WEPCH013	Electron Transport Line Optimization using Neural Networks and Genetic Algorithms	1948
	D. Schirmer, T. Buening, P. Hartmann, D. Mueller DELTA, Dortmund
	Methods of computational intelligence (CI) were investigated to support the optimization of the electron transfer efficiency from the booster synchrotron BoDo to the electron storage ring DELTA. Neural networks and genetic algorithms were analysed alternatively. At first both types of methods were trained on the basis of a theoretical model of the transport line. After the training various algorithms were used to improve the magnet settings of the real transport line elements with respect to the electron transfer efficiency. The results of different strategies are compared and prospects as well as limitations of CI-methods to the application of typical optimization problems in accelerator operation are discussed.
WEPCH015	Measurement and Correction of Dispersion in the VUV-FEL	1951
	E. Prat, W. Decking, T. Limberg DESY, Hamburg
	Increase in transverse beam size in the undulator caused by dispersive effects is one of the major limitations for the operation of FLASH, the VUV-FEL at DESY. Sources of the (spurious) dispersion are field errors and stray magnet fields in the undulator beam line as well as spurious dispersion created upstream of the undulator by, for instance, rf coupler kicks, magnet misalignments and field errors. The impact of these errors on dispersion generation depends on the actual operating conditions of the accelerator, so the dispersion must be measured and controlled frequently. In this paper we present numerical studies of spurious dispersion generation, first dispersion measurements and correction results.
WEPCH016	Spurious Vertical Dispersion Correction for PETRA III	1954
	G.K. Sahoo, K. Balewski, W. Decking DESY, Hamburg
	Spurious vertical dispersion, arising due to the misalignment and rotational errors of magnets in synchrotron radiation sources with low emittances, are highly undesirable as this contributes to the vertical beam size of the photon beam. This is a matter of concern in PETRA III, a 6GeV light source with a designed horizontal emittance of 1nm.rad and 1% emittance coupling. It has a hybrid lattice of FODO and DBA cells, which will be installed in one-eighth of the existing PETRA II ring. In this paper local and global vertical dispersion corrections are discussed. The global vertical dispersion is corrected using vertical corrector magnets (may also consider 12 skew quadrupole magnets), and the skew quadrupoles are used for local correction as well. Eight of them are placed close to the two damping wiggler sections used for minimizing the horizontal emittance. The remaining four are placed in the new octant with DBA cells where insertion devices are installed.
WEPCH017	Front-to-end Simulation of the Injector Linac for the Heidelberg Ion Beam Therapy Centre	1957
	R. Cee HIT, Heidelberg C.M. Kleffner, M.T. Maier, B. Schlitt GSI, Darmstadt U. Ratzinger, A. Schempp IAP, Frankfurt-am-Main
	The injector linac of the Heidelberg ion beam therapy centre is currently in the commissioning phase. Its main components are two electron cyclotron resonance ion sources (ECRIS), a radio-frequency quadrupole accelerator (RFQ) and an interdigital H-type drift tube linac (IH-DTL). It will be able to accelerate beams of hydrogen-, helium-, carbon- and oxygen-ions up to a specific energy of 7 MeV per nucleon. This contribution focuses on the beam dynamics simulation of the transport lines and the accelerating structures. Three dedicated tools have been employed: Mirko for the beam transport, RFQmed for the particle dynamics through the RFQ and LORASR for the acceleration in the IH-DTL. Between the different beam dynamics codes interfaces have been implemented and a front-to-end simulation has been performed. Comparisons with alternative programmes confirm the results obtained. The work will enable us to investigate the behaviour of the machine in a theoretical model during the forthcoming operating.
WEPCH018	Finite Elements Calculations of the Lattice and Ring Acceptance of the Heidelberg CSR	1960
	H. Fadil, M. Grieser, A. Wolf, R. von Hahn MPI-K, Heidelberg
	A new Cryogenic Storage Ring (CSR) is currently being designed at MPI-K in Heidelberg. This electrostatic ring, which will store ions in the 20~300 keV energy range (E/Q), has a total circumference of 35.2 m and a straight section length of 2.8 m. The ring design was at first carried out with the optics code MAD in the first order approximation. Further investigation of the optics was performed with the finite elements electrostatic code TOSCA. The individual elements of the CSR (deflectors and quadrupoles) were calculated then a model of the entire ring was simulated with successful storage (tracking) of 20keV protons for many turns. The lattice parameters thus obtained were compared with the MAD results and show good agreement. The dynamic ring acceptance was also calculated for the standard operating point.
WEPCH020	Extending the Linear Least Squares Problem for Orbit Correction in Circular Accelerators	1963
	C. Scafuri ELETTRA, Basovizza, Trieste
	A method for extending the linear least squares problem applicable for correcting the orbit of circular accelerators is proposed. The method is based on the definition of a suitable cost function which weighs both orbit deviations and the correction effort, that is steerer kicks. The paper presents the full derivation of the formulas and the results of simulations. The application of this method for the Global Orbit Feedback system of the ELETTRA storage ring is being evaluated.
WEPCH021	Generalized Twiss Coefficients Including Transverse Coupling and E-beam Growth	1966
	F. Ciocci, G. Dattoli ENEA C.R. Frascati, Frascati (Roma) M. Migliorati Rome University La Sapienza, Roma
	We use a generalization of the Twiss coefficients to the fully transverse coupled case. We show that the formalism is particularly useful to treat problems involving the beam optics of electrons propagating in undulators or solenoids. The method allows the treatment in analytical terms, we generalize the method including the effect of spatial charges and higher order multi-polar terms. The method is then applied to a specific example relevant to e-beam emittance dilution in solenoid and exotic undulators.
WEPCH022	Study of the Effect of Multipolar Components in the SPARC Emittance Compensation Gun Solenoid	1969
	C. Ronsivalle, G. Dattoli, L. Picardi, M. Quattromini ENEA C.R. Frascati, Frascati (Roma) G. Bazzano CNAO Foundation, Milan M. Ferrario, M. Migliorati, L. Palumbo, M.A. Preger, C. Sanelli INFN/LNF, Frascati (Roma) P. Musumeci INFN-Roma, Roma J.B. Rosenzweig UCLA, Los Angeles, California
	The SPARC photoinjector rf gun requires a solenoid immediately downstream for emittance compensation. The analysis of the measured solenoid magnetic maps shows the existence of multipolar components added to the pure solenoid field. The effect of these added fields on beam dynamics and possible correction schemes have been studied from the theoretical point of view and by numerical calculations based on PARMELA/TREDI codes. An accurate 3D numerical modelization by using CST EM Studio has been done, in order to investigate the source of these multipolar components and to suggest some design modifications aimed to reduce their magnitude. The results of this study are presented here.
WEPCH023	Longitudinal Coherent Oscillation Induced in Quasi-isochronous Ring	1972
	Y. Shoji, Y. Hisaoka, T. Matsubara, T. Mitsui NewSUBARU/SPring-8, Laboratory of Advanced Science and Technology for Industry (LASTI), Hyogo
	Noise sources, which excite longitudinal coherent oscillation is discussed. Especially in a quasi-isochronous electron storage ring an identification of the noise sources is important to obtain an extremely short bunch. One possible source is a well-known rf noise in the acceleration field. The other is a magnetic field ripple, which changes a path-length for a revolution. The analytical formula for the longitudinal coherent oscillation is explained. It contains the path-length oscillation, which had never been considered. The third is a beam itself, probably be a coherent radiation loss. The driving term is not symmetric along the energy axis, then the oscillation amplitude depends on the higher order momentum compaction factor.
WEPCH024	Matrix Formulation for Hamilton Perturbation Theory of Linearly Coupled Betatron Motion	1975
	M. Takao JASRI/SPring-8, Hyogo-ken
	Linear coupled motion in a circular accelerator was successfully parametrized through the transfer matrix approach, where normal mode Twiss and coupling parameters are defined as an extension of Courand and Snyder formulation. However it is not straightforward to assign analytical expressions to the coupling parameters. On the other hand the coupled motion was analytically solved by the Hamilton perturbation theory, which ingeniously describes the resonance phenomena. In the perturbation theory, however, the symplectic structure of the coupled motion is obscure in turn. Hence, for the purpose of combining both the theories with each other with keeping the respective virtues, we develop the matrix formulation based on the Hamilton perturbation theory. Since we have already known the solution of equation of motion, we can construct the transfer matrix in terms of the solution. Thus we formulate the betatron motion with linear coupling resonance in analytic and symplectic manner. As an application of the formulation, we investigate the two-dimensional beam ellipse in an electron storage ring.
WEPCH025	COD Correction at the PF Ring by New Orbit Feedback Scheme	1978
	K. Harada, T. Obina KEK, Ibaraki N. Nakamura, H. Sakai, H. Takaki ISSP/SRL, Chiba
	When we correct the global COD (closed orbit distortion), if we use the modified conversion matrix calculated by the eigen vector method with constraint conditions (EVC), the local orbit correction can be simultaneously done to fix the light source point in the insertion device. In the EVC, the local orbit correction is combined to the global orbit correction by the Lagrange's undetermined multiple method. In this paper, we show the machine study results at the PF Ring.
WEPCH026	Recent Progress of Optics Measurement and Correction at KEKB	1981
	A. Morita, H. Koiso, Y. Ohnishi, K. Oide KEK, Ibaraki
	We present the progress of the optics measurement and the correction scheme of the KEKB operation for example off-momentum beta correction.
WEPCH028	Position Shuffling of the J-PARC Main Ring Magnets	1984
	M. Tomizawa, K. Fan, S. Igarashi, K. Ishii, H. Kobayashi, A.Y. Molodozhentsev, K. Niki, E. Yanaoka KEK, Ibaraki Y. Irie JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken S. Machida CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
	The J-PARC 50GeV main ring has 96 dipole, 216 quadrupole with 11 families and 72 sextupole magnets with 3 families. Magnets installation in the tunnel started last year and will be planed to finish by the end of next fiscal year. Field measurements of all magnets will soon finish by this March. Deviations for BL, B'L, B"L in dipole, quadrupole and sextupole magnets make COD, beta beat and third integer stopband, respectively. They can be reduced by choosing a pair of magnets with similar field deviation and by positioning them so as to cancel each other considering betatron phase (shuffling). In this paper, we will report our shufflling scheme chosen under the given schedule for installation and field measurements and also will show performances expected by the shufflings.
WEPCH029	Injection and Extraction Orbit of the J-PARC Main Ring	1987
	M. Tomizawa, Y. Kamiya, H. Kobayashi, I. Sakai, Y. Shirakabe KEK, Ibaraki S. Machida CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
	The J-PARC main ring (MR) accelerates a high intensity proton beam and deliver to the neutrino experimental hall by the fast extraction and to the hadron experimental facility by the slow extraction. The beam from the rapid cycle synchrotron (RCS) is injected by the bunch to bucket transfer into the MR. The MR has two beam dump lines, the first one is used to dump the beam at injection energy and the second one can be used to abort accelerated beam. The beam loss at the injection and extraction is one of the critical issue for high intensity proton accelerators. We report designed injection and extraction orbits and discuss about the beam apertures and the beam loss.
WEPCH030	Beam Dynamics of a 175MHz RFQ for an IFMIF Project	1990
	S. Maebara, S. Moriyama, M.S. Sugimoto JAEA, Ibaraki-ken M.S. Saigusa 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 12.6　m was designed to keep the minimum emittance growth with the RF injection power of 2.3MW CW. For such a 12m-long RFQ, two coupling plates are indispensable in order to suppress higher modes in a longitudinal direction at least. From beam dynamics point views, the transmission co-efficient has been evaluated by TOUTATIS code, and it is found that the transmission decay within 0.5% can be achieved by employing a gap width of less than 4mm for a coupling plate design.
WEPCH032	Orbit Correction System for S-LSR Dispersion-free Mode	1993
	H. Souda, S. Fujimoto, M. Ikegami, A. Noda, T. Shirai, M. Tanabe Kyoto ICR, Uji, Kyoto H. Fadil MPI-K, Heidelberg
	An ion storage ring S-LSR has been constructed at ICR, Kyoto Univ. It is a small ring with 22.557m circumference, and has an electron cooler and laser cooling section to achieve crystalline beam. In the commissioning process, closed orbit correction of a 7MeV proton beam has been successfully realized by means of Simplex Method. Responses to the correctors are linear only within narrow limits because of the space-charge effect in the electron cooler. Therefore, the correction must be repetition of small corrections. Under such condition, measured COD has been reduced less than 0.1mm. Orbit correction is necessary for 35keV Mg+ dispersion-free mode* using both bending magnets and electrostatic deflectors. Since electrostatic deflectors have relatively large field errors, it needs a special process to inject the beam into the dispersion-free mode ring. First circulation is under only the magnetic field, then, the electric field will be added little by little applying continuous COD correction. In this way the dispersion gradually diminishes with keeping stable orbit. In this paper we present the correction scheme and the trial to the dispersion-free circulation. *M. Ikegami et al. Phys. Rev. ST-AB, 7, 120101-1 (2004).
WEPCH033	Single Particle Beam Dynamics Design of CSNS/RCS	1996
	S. Wang, S.X. Fang, Q. Qin, J. Tang IHEP Beijing, Beijing J. Wei BNL, Upton, Long Island, New York
	Rapid Cycling Synchrotron (RCS) is a key component of Beijing Spallation Neutron Source (BSNS). It accumulates and accelerates protons to design energy of 1.6 GeV and extracts high energy beam to the target. As a high beam density and high beam power machine, low beam loss is also a basic requirement. An optimal lattice design is essential for the cost and the future operation. The lattice design of BSNS is presented, and the related dynamics issues are discussed. The injection/extraction scheme and the beam collimation system design are introduced.
WEPCH036	Design of Short Bunch Compressors for the International Linear Collider	1999
	E.-S. Kim PAL, Pohang, Kyungbuk
	We present a two-stage bunch compressor system that was selected as alternative design in the ILC BCD (baseline configuration design). Initial beam with bunch length of 6 mm rms can be compressed to 150 micron rms in the bunch compressor, but the system uses a single chicane for each stage of compression, rather than the 12 chicanes used in the baseline design. We present the design scheme and performances of the system in detail, including scheme for emittance tuning in the system.
WEPCH038	Nonlinear Characteristics of the TME Cell	2002
	V.A. Kvardakov, E. Levichev BINP SB RAS, Novosibirsk
	The TME (Theoretical Minimum Emittance) cell is being used now for designing the lattice of different storage rings (SR sources, damping rings, FFAG accelerators, etc.). Strong sextupoles required to correct the natural chromaticity of the lattice reduce the dynamic aperture. In the paper we consider the main features of the nonlinear perturbation strength and its connection with the essential lattice parameters: horizontal emittance, betatron tunes, and natural chromaticity. The analytical results are compared with the computer simulation.
WEPCH040	Further Development of Irradiation Field Forming Systems of Industrial Electron Accelerators	2005
	N.G. Tolstun, A.S. Ivanov, V.P. Ovchinnikov, M.P. Svinin NIIEFA, St. Petersburg
	Electron beam irradiation field forming systems where accelerated electron beam is scanned in a constant field of the elongated bending magnets were developed in our institute more than 15 years ago and they have a number of advantages in comparison with traditional ones. Since than they have been applied in two accelerators with energies 300 and 400 keV; version of the similar system with two electromagnets for two-side irradiation of flexible materials – in a number of 750 keV high voltage accelerators ("Electron-10") successfully operating now in several industrial lines. Systems of forming of electron beam irradiation field based on the same principle have been used in several projects, some of them are already put into operation. Electron optic characteristics of such systems and their various modifications as well as aspects of their possible usage are discussed in the paper.
WEPCH041	Analytic Study of Longitudinal Dynamics in Race-track Microtrons	2008
	Yu.A. Kubyshin UPC, Barcelona A.V. Poseryaev, V.I. Shvedunov MSU, Moscow
	Implementation of low energy injection schemes in the race-track microtron (RTM) design requires a better understanding of the longitudinal beam dynamics. Differently to the high energy case a low-energy beam will slip in phase relative to the accelerating structure phase. We generalize the concept of equilibrium or synchronous particle for the case of non-relativistic energies and introduce the notion of transition energy for RTMs. An analytical approach for the description of the synchronous phase slip is developed and explicit, though approximate, formulas which allow to define the equilibrium injection phase and fix the parameters of the accelerator are derived. The approximation can be improved in a systematic way by calculating higher order corrections. The precision of the analytical approach is checked by direct numerical computations using the RTMTrace code and was shown to be quite satisfactory. Explicit examples of injection schemes and fixing of RTM global parameters are presented.
WEPCH043	On the Implementation of Experimental Solenoids in MAD-X and their Effect on Coupling in the LHC	2011
	A. Koschik, H. Burkhardt, T. Risselada, F. Schmidt CERN, Geneva
	The betatron coupling introduced by the experimental solenoids in the LHC is small at injection and negligible at collision energy. We present a study of these effects and look at possible corrections. Additionally we report about the implementation of solenoids in the MAD-X program. A thin solenoid version is also made available for tracking purposes.
WEPCH044	Interaction Region with Slim Quadrupoles	2014
	E. Laface, R. Ostojic, W. Scandale, D. Tommasini CERN, Geneva C. Santoni Université Blaise Pascal, Clermont-Ferrand
	An optical performance's improvement of the interaction region can be obtained with the addition of new quadrupoles in the forward detectors area. Such scenario would allow decreasing the $β*$ below the nominal value. The basic concept consists in using quadrupoles to break the quadratic behavior of $β$ in the free space between the IP and the IR triplets. In this new configuration we present the performance improvements and the hardware requirements.
WEPCH045	Sorting Strategies for the Arc Quadrupoles of the LHC	2017
	Y. Papaphilippou, A.M. Lombardi CERN, Geneva
	The variation in the field gradient of the LHC arc quadrupoles can not be corrected independently by the dedicated trim quadrupole circuits. This may result to a beta function beating larger than the one accepted by the machine budget. In this respect, sorting strategies for the installation of these magnets were implemented in order to eliminate this effect, as locally as possible. Special care was taken for quadrupoles whose warm measurements showed large gradient errors due to an excessive magnetic permeability. The figures of merit used in the sorting and the results obtained for all 8 sectors of the LHC are detailed. The global optics function beating foreseen, as computed by both analytical estimates and simulations with MAD-X are finally presented.
WEPCH046	Design and Validation with Measurements of the LEIR Injection Line	2020
	F. Roncarolo, C. Carli, M. Chanel, L.D. Dumas, R. Scrivens CERN, Geneva
	The CERN Low Energy Ion Ring (LEIR) commissioning started in the year 2005. O⁴⁺ and Pb⁵⁴⁺ 4.2 MeV/nucleon ion beams are transferred from Linac 3 to LEIR through a low energy transfer line, for which the constraints and the resulting optics design are presented. First trajectory and dispersion measurements agreed only poorly with the theoretical model. Iterations of a refined optics model and further measurements improved the agreement between experimental observations and expectations. In particular, the effect of quadrupolar errors in the line dipole magnets is discussed.
WEPCH047	Procedures and Accuracy Estimates for Beta-beat Correction in the LHC	2023
	R. Tomas, O.S. Brüning, S.D. Fartoukh, M. Giovannozzi, Y. Papaphilippou, F. Zimmermann CERN, Geneva R. Calaga, S. Peggs BNL, Upton, Long Island, New York F. Franchi GSI, Darmstadt
	The LHC aperture imposes a tight tolerance of 20% on the maximum acceptable beta-beat in the machine. An accurate knowledge of the transfer functions for the individually powered insertion quadrupoles and techniques to compensate beta-beat are key prerequisites for successful operation with high intensity beams. We perform realistic simulations to predict quadrupole errors in LHC and explore possible ways of correction to minimize beta-beat below the 20% level.
WEPCH048	Measurement and Modeling of Magnetic Hysteresis in the LHC Superconducting Correctors	2026
	W. Venturini Delsolaro, L. Bottura, Y. C. Chaudhari, M. Karppinen CERN, Geneva N.J. Sammut University of Malta, Faculty of Engineering, Msida
	The Large Hadron Collider, now under construction at CERN, relies heavily on superconducting magnets for its optics layout: besides the main magnets, almost all the correcting magnets are superconducting. Along with clear advantages, this brings about complications due to the effects of persistent currents in the superconducting filaments. Correcting magnets that trim key beam parameters or compensate field errors of the main magnets (among others those due to hysteresis), are in their turn hysteretic. The measured magnetic hysteresis and its possible influence on accelerator operation will be presented, in particular the real-time compensation of decay and snapback in the main magnets, and the reproducibility between runs. A detailed characterization of minor hysteresis loops is given, as well as degaussing cycles and modeling work.
WEPCH049	Closed Orbit Correction of TPS Storage Ring	2029
	H.-J. Tsai, H.-P. Chang, P.J. Chou, C.-C. Kuo, G.-H. Luo, M.-H. Wang NSRRC, Hsinchu
	A 3 GeV synchrotron storage ring is proposed in Taiwan to serve the synchrotron light users, especially for the x-ray community. The ring consists of 24 double-bend cells with 6-fold symmetry and the circumference is 518.4 m. The designed natural emittance with slightly positive dispersion in the straight sections is less than 2 nm-rad. This low emittance lattice structure needs strong quadrupoles and sextupoles and the closed orbit distortions are sensitive to the alignment errors in the quadrupoles and sextupoles as well. The closed orbit distortions due to tolerable magnetic errors are simulated and the correction scheme is proposed. Using singular value decomposition method, the closed orbit distortions are corrected and corrector strengths as well as the residual closed orbit distortions are obtained.
WEPCH050	Correction of Vertical Dispersion and Betatron Coupling for the TPS Storage Ring	2032
	H.-J. Tsai, H.-P. Chang, P.J. Chou, C.-C. Kuo, G.-H. Luo, M.-H. Wang NSRRC, Hsinchu
	A proposed 3 GeV Taiwan Photon Source (TPS) is a low emittance (1.7 nm-rad) medium energy storage ring with 24 DBA cells. The vertical emittance due to betatron coupling and spurious vertical dispersion generated by the magnet errors and off-center orbits in sextupoles and quadrupoles are analyzed. The sensitivities due to magnetic alignment errors are estimated. Using the SVD method, the result of global vertical dispersion and betatron coupling correction is presented.
WEPCH051	Isochronous Magneto-optical Structure of the Recirculator SALO	2035
	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
	With the goal to provide low energy spread of electron beam, the magneto-optical structure of the recirculator SALO has been modified. All of its parts (an injection tract and arcs) were made isochronous and achromatic. Besides, with the purpose of the accelerating structure arrangement, the length of straight sections was enlarged. The amplitude and dispersion functions on various recirculator sections and design characteristics of the beam are submitted.
WEPCH052	Injection System for Kharkov X-ray Source NESTOR	2038
	A.Y. Zelinsky, P. Gladkikh, I.M. Karnaukhov, A. Mytsykov NSC/KIPT, Kharkov
	During the last three years a Kharkov X-ray generator NESTOR is under design and construction in NSC KIPT. According to the design report, electrons are injected in the storage ring at 100 MeV and ramped up to final energy 225 MeV. Due to compact design of the ring the injection trajectory of the beam will pass through fringe field of a NESTOR bending magnet. It brings additional difficulties on design of an injection channel. In the paper the layout, results of design and calculations of NESTOR injector channel are presented. The channel consists of two bending magnets, five-lens, asymmetrical, objective and two-lens matching cell to compensate dispersion and focusing effects of a dipole magnet fringe field and injection system elements (inflector). Presented results shows that designed lattice provides matching of injected beam parameters with the storage ring acceptance, is stable to element alignment errors and is easy controlled. The final values of the channel lens gradients can be defined only after measurements of inflector field profile.
WEPCH053	Peculiarities of Influence of Coherency Processes at Charged Particles Channeling on Particle Beams Characteristics	2041
	V.I. Vysotskii, M.V. Vysotskyy National Taras Shevchenko University of Kyiv, Radiophysical Faculty, Kiev
	In the work the length of reciprocal coherency existence and peculiarities of coherency of different states of channeled particles wave functions are discussed. It was shown that the length of coherent channeling depends on the monochromaticity of initial particle beam as well as on the interaction of channeled particles with thermal oscillations of the crystal lattice. Peculiarities of influence of coherency processes at relativistic and nonrelativistic charged particles channeling on spatial and angular characteristics of particle beam that has passed through a thin crystal are discussed. In was shown, that the influence of different particle states interference within the area of coherent channeling leads to very strong periodic dependence of final beam angular width from the crystal length. This effect allows to control beam parameters (e.g., to form narrower beam, that it was before falling on the crystal). Influence of coherency of particle states in a single channel and several channels on the angular distribution and the possibility of quasicharacteristic short-wave spontaneous and stimulated radiation is also studied.
WEPCH054	Matrix Formalism for Current-independent Optics Design	2044
	C.-X. Wang, K.-J. Kim ANL, Argonne, Illinois
	Matrix formalism has been a powerful tool for beam optics designs. It not only facilitates computations but also plays an important role in formulating various design concepts. Here we extend the standard matrix formalism for the purpose of designing an optics that transports space-charge-dominated intense beam. Furthermore, we explore the concept of current-independent optics, which can be useful for systems such as high-brightness injectors and space-charge-dominated rings. Our discussion here is preliminary and limited to axisymmetric systems.
WEPCH055	A New Algorithm for the Correction of the Linear Coupling at TEVATRON	2047
	Y. Alexahin, E. Gianfelice-Wendt Fermilab, Batavia, Illinois
	The Fourier analysis of TBT data provides valuable information about the machine linear and non-linear optics. The recent upgrade of the Beam Position Monitors system made it possible to exploit this technique also at Tevatron. A program for the measurement and correction of the linear coupling based on this approach has been integrated in the TEVATRON control system. With respect to the method based on the empirical adjustment of the strength of the skew quadrupoles, the new method has the advantage of being faster and of allowing the measurement of the coupling also during the acceleration. Moreover it offers also information about the sum coupling coefficient and about the location of the sources of coupling.
WEPCH057	Measurement and Optimization of the Lattice Functions in the Debuncher Ring at Fermilab	2050
	V.P. Nagaslaev, K. Gollwitzer, V.A. Lebedev, A. Valishev Fermilab, Batavia, Illinois V. Sajaev ANL, Argonne, Illinois
	A goal of the Tevatron Run-II upgrade requires substantial increase of antiproton production. The central step towards this goal is increasing the Debuncher ring admittance. Detailed understanding of the Debuncher's optics, aperture limitations and lattice functions is necessary. The method of the response matrix optimization has been used to determine quadrupole errors and corrections to the design functions. The measurement accuracy is about 5% due to the Beam Position Monitor system resolution and the small number of steering elements in the machine. We have used these accurate measurements to redesign the machine optics to maximize the acceptance of the Debuncher where the main limiting apertures are the stochastic cooling pickups and kickers. Accuracy of the measurements and the limitations are discussed as well as details of the optics modification.
WEPCH058	Progress with Collision Optics of the Fermilab Tevatron Collider	2053
	A. Valishev, Y. Alexahin, G. Annala, V.A. Lebedev, V.P. Nagaslaev Fermilab, Batavia, Illinois V. Sajaev ANL, Argonne, Illinois
	Recent advances in the measurement and modeling of the machine parameters and lattice functions at the Tevatron allowed modifications of the collision optics to be performed in order to increase the collider luminosity. As the result, beta functions in the two collision points were decreased from 35cm to 29cm which resulted in ~10% increase of the peak luminosity. In this report we describe the results of optics measurements and corrections. We also discuss planned improvements, including the new betatron tune working point and correction of the beta function chromaticity.
WEPCH059	Linear Lattice Modeling of the Recycler Ring at Fermilab	2056
	M. Xiao, V.P. Nagaslaev, A. Valishev Fermilab, Batavia, Illinois V. Sajaev ANL, Argonne, Illinois
	The Recycler Ring at Fermilab is a fixed 8 GeV kinetic energy storage ring, by the use of permanent magnets in the ring lattice. It is a strong focusing FODO lattice made up of either two gradient magnets or two quadrupoles(in dispersion free straight sections). The magnetic properties of all magnets used were measured before installation and surveyed in place to minimize possible errors. Nevertheless, substantial differences are found in tunes and beta functions between the existing linear model and the real storage ring. It results in difficulties when tuning the machine to new lattice conditions. We are trying to correct the errors by matching the model into the real machine using Orbit Response Matrix(ORM) method. The challenge with ORM particular in this ring and the results are presented in this paper.
WEPCH060	Linear and Nonlinear Coupling Using Decoupling Transformations	2059
	A. Wolski, A. Sessler LBNL, Berkeley, California
	Linear coupling in a storage ring is conveniently analyzed in terms of transformations that put the single-turn map into block-diagonal form. Such a transformation allows us to define new variables, in which the dynamics are uncoupled. Thus, for example, the symplectic conditions are simply that the phase area in each of the uncoupled variables is preserved. In principle, a similar approach may be taken to nonlinear coupling; we discuss such an approach in this paper, giving some simple illustrations of the ideas, based on the well-known techniques of normal form analysis. We also discuss some obstacles to finding a nonlinear decoupling transformation in the general case.
WEPCH061	SABER Optical Design	2062
	R.A. Erickson, K.L.F. Bane, P. Emma, Y. Nosochkov SLAC, Menlo Park, California
	SABER, the South Arc Beam Experimental Region, is a proposed new beam line facility designed to replace the Final Focus Test Beam at SLAC. In this paper, we outline the optical design features and beam parameters now envisioned for SABER. A magnetic chicane to compress positron bunches for SABER and a bypass line that could transport electrons or positrons from the two-thirds point of the linac to SABER, bypassing the LCLS systems, are also discussed.
WEPCH062	Precision Measurement and Improvement of Optics for e+, e^- Storage Rings	2065
	Y.T. Yan, Y. Cai, W.S. Colocho, F.-J. Decker, J. Seeman, M.K. Sullivan, J.L. Turner, U. Wienands, M. Woodley, G. Yocky SLAC, Menlo Park, California
	Through horizontal and vertical excitations, we have been able to make a precision measurement of linear geometric optics parameters with a Model-Independent Analysis (MIA). We have also been able to build up a computer model that matches the real accelerator in linear geometric optics with an SVD-enhanced Least-square fitting process. Recently, with the addition of longitudinal excitation, we are able to build up a computer virtual machine that matches the real accelerators in linear optics including dispersion without additional fitting variables. With this optics-matched virtual machine, we are able to find solutions that make changes of many normal and skew quadrupoles for machine optics improvement. It has made major contributions to improve PEP-II optics and luminosity. Examples from application to PEP-II machines will be presented.
WEPCH063	Measurements and Modeling of Eddy Current Effects in BNL's AGS Booster	2068
	K.A. Brown, L. Ahrens, C.J. Gardner, J. Glenn, M. Harvey, W. Meng, K. Zeno BNL, Upton, Long Island, New York
	Recent beam experiments at BNL's AGS Booster have enabled us to study in more detail the effects of eddy currents on the lattice structure and our control over the basic lattice parameters of betatron tune and chromaticity. The Booster is capable of operating at ramp rates as high as 8 T/sec. At these ramp rates eddy currents in the vacuum chambers have significant effects on the fields and gradients seen by the beam as it is accelerated. The Booster was designed with these effects in mind and to help control the field uniformity and linearity in the Booster Dipoles special vacuum chambers were designed with current windings to negate the effect of the induced eddy currents. In this report results from measurements of these effects will be presented. Results from modeling and comparisons to the measurements will also be presented.
WEPCH064	Fast Compensation of Global Linear Coupling in RHIC using AC Dipoles	2071
	F. Franchi GSI, Darmstadt R. Calaga BNL, Upton, Long Island, New York R. Tomas CERN, Geneva
	Global linear coupling has been extensively studied in accelerators and several methods have been developed to compensate the coupling vector C using skew quadrupole families scans. However, scanning techniques can become very time consuming especially during the commissioning of an energy ramp. In this paper we illustrate a new technique to measure and compensate, in a single machine cycle, global linear coupling from turn-by-turn BPM data without the need of a skew quadrupole scan. The algorithm is applied to RHIC BPM data using AC dipoles and compared with traditional methods.
WEPCH065	Lattices for High-power Proton Beam Acceleration and Secondary Beam Collection, Cooling, and Deceleration	2074
	S. Wang IHEP Beijing, Beijing K.A. Brown, C.J. Gardner, Y.Y. Lee, D.I. Lowenstein, S. Peggs, N. Simos, J. Wei BNL, Upton, Long Island, New York
	Rapid-cycling synchrotrons are used to accelerate high-intensity proton beams to energies of tens of GeV for secondary beam production. After primary beam collision with a target, the secondary beam can be collected, cooled, accelerated or decelerated by ancillary synchrotrons for various applications. In this paper, we first present a lattice for the main synchrotron. This lattice has: a) flexible momentum compaction to avoid transition and to facilitate RF gymnastics b) long straight sections for low-loss injection, extraction, and high-efficiency collimation c) dispersion-free straights to avoid longitudinal-transverse coupling, and d) momentum cleaning at locations of large dispersion with missing dipoles. Then, we present a lattice for a cooler ring for the secondary beam. The momentum compaction across half of this ring is near zero, while for the other half it is normal. Thus, bad mixing is minimized while good mixing is maintained for stochastic beam cooling.
THOAFI03	Global and Local Coupling Compensation in RHIC using AC Dipoles	2774
	R. Calaga BNL, Upton, Long Island, New York F. Franchi GSI, Darmstadt R. Tomas CERN, Geneva
	Compensation of transverse coupling during the RHIC energy ramp has been proven to be non-trivial and tedious. The lack of accurate knowledge of the coupling sources has initiated several efforts to develop fast techique using turn-by-turn BPM data to identify and compensate these sources. This paper aims to summarize the beam experiments performed to measure the coupling matrix and resonance driving terms with the aid of RHIC ac dipoles.
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