dynamic-aperture

Paper	Title	Other Keywords	Page
MOPKF012	A 7T Multipole Wiggler in BESSY II: Implementation and Commissioning Results	wiggler, radiation, vacuum, optics	324
	E. Weihreter, J. Feikes, P. Kuske, R. Müller, G. Wustefeld BESSY GmbH, Berlin D. Berger HMI, Berlin N.A. Mezentsev, V. Shkaruba BINP SB RAS, Novosibirsk
	To generate hard X-ray beams for residual stress analysis and for magnetic scattering with the BESSY II SR source, a 7T wiggler with 17 poles has been implemented. Several problems had to be solved. Wake fields induced by smaller steps in the geometry of the radiation shield inside the beam chamber led to intolerable LHe consumption, which have been analysed numerically and then cured by improving the shield geometry. Much of the routine operation procedures are influenced by the unusually high radiation power level of max. 55 kW. For system protection an interlock system dumps the electron beam automatically in case of relevant error events. This wiggler is by far the strongest perturbation of the linear beam optics, breaking seriously the symmetry of the ring. Beam optical parameters including tune shift and beta beat have been measured to quantify these perturbations and develop efficient cures to limit the negative effects on beam lifetime and dynamic aperture. So far the wiggler is operated at 2.8 T and max. currents up to 250 mA in normal user shifts.
MOPKF039	The ELETTRA Superconducting Wiggler	electron, wiggler, insertion, insertion-device	390
	L. Tosi, C. Knapic, D. Zangrando ELETTRA, Basovizza, Trieste
	A 3.5 Tesla 64 mm period superconducting wiggler has been installed in the ELETTRA storage ring as a photon source for a future X-ray diffraction beamline. After several technological upgrades, a series of measurements were carried out to characterize the device and its effects on the electron beam, such as optics distortion and dynamic aperture. A description of the upgrades and measurements are presented.
MOPLT122	Dynamical Aperture Study for the NLC Main Damping Rings	wiggler, damping, lattice, octupole	824
	M. Venturini, S. Marks, A. Wolski LBNL, Berkeley, California
	A sufficiently large acceptance is critical for the NLC Main Damping Rings (MDR) as the high power carried by the beams demands very high injection efficiency. Both chromatic sextupoles and wiggler insertions, needed for damping, are substantial sources of nonlinearities limiting the dynamical aperture. We report on our latest studies on single particle dynamics for the MDR current lattice with and without inclusion of lattice errors and with attention paid to working point optimization. The possibility to use octupole magnets for compensation is also explored.
TUPLT019	Nonlinear Effects Studies for a Large Acceptance Collector Ring	sextupole, quadrupole, optics, lattice	1177
	A. Dolinskii, K. Beckert, P. Beller, B.  Franzke, F. Nolden, M. Steck GSI, Darmstadt
	A large acceptance collector ring (CR) is designed for fast cooling of rare isotope and antiproton beams, which will be used for nuclear physics experiments in the frame of the new international accelerator facility recently proposed at GSI. This contribution describes the linear and non-linear optimisation used to derive a lattice solution with good dynamic behaviour simultaneously meeting the demands for very fast stochastic cooling for two optical modes (for rare isotope and antiproton beams). Effects due to non-linear field contributions of the magnet field in dipoles and quadrupoles are very critical in this ring. Using a single particle dynamics approach, the major magnetic non-linearities of the CR are studied. We discuss the particle dynamics of the dipole and quadrupole fringe fields and the their influence on the dynamic aperture and on the tune. Additionally, the CR will be operated at the transition energy (isochronous mode) for time of flight (TOF) mass spectrometery of short-lived radioactive ions. For this mode a specific correction scheme is required to reach a high degree of isochronism over a large acceptance.
TUPLT093	Tune Survey of Dynamic Apertures for High-brilliance Optics of the Pohang Light Source	emittance, lattice, betatron, simulation	1375
	E.-S. Kim PAL, Pohang
	The PLS storage ring is a 2.5 GeV light source and the dynamic apertures in a lattice for the low emittance in the ring have been investigated by a simulation method. The dynamic apertures that include effects of machine errors and insertion devices were obtained by a tune survey in the simulation. It was also shown that how large are the dynamic aperture compensated after corrections of a CODs. The betatron tune for the operation of the high-brilliance lattice are investigated based on the view point of dynamic apertures obtained from a tune survey.
WEOALH03	Installation Strategy for the LHC Main Dipoles	dipole, injection, multipole, resonance	176
	S.D. Fartoukh CERN, Geneva
	All positions in the LHC machine are not equivalent in terms of beam requirements on the geometry and the field quality of the main dipoles. In the presence of slightly or strongly out-of tolerance magnets, a well-defined installation strategy will therefore contribute to preserve or even optimize the performance of the machine. In view of present state of the production, we have anticipated a list of potential issues (geometry, transfer function, field direction and random b3) which, combined by order of priority, have been taken into account to define a robust installation algorithm for the LHC main dipoles. Among the different possible strategies, the proposed one has been optimised in terms of simplicity and flexibility in order not to slow down and complicate the installation process. Its output is a prescription for installing the available dipoles in sequence while reducing to an absolute minimum the number of holes required by geometry or field quality issues.
	Video of talk
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WEPKF008	A Strategy for Sampling of the Field Quality of the LHC Dipoles	dipole, multipole, target, injection	1606
	L. Bottura, S.D. Fartoukh, V. Granata, E. Todesco CERN, Geneva
	We have measured the magnetic field of a considerable fraction of the superconducting LHC main dipoles, of the order of 300 in warm conditions and 100 in cold conditions. All LHC dipoles will be measured in warm conditions at the manufacturers to steer the production inside the acceptance limits imposed by beam dynamics. Using the available data we analysed the distributions of the main field and higher order field errors in warm and cold conditions, as well as the distribution of the warm-to-cold correlation. Based on this analysis we predict the minimum number of magnets that should be measured in cold conditions in order to guarantee that (1) the production is controlled within the specified limits (2) the field is known to a sufficient level for a sound installation and (3) the uncertainty on the knowledge of the magnetic field of the LHC dipoles is small enough for the commissioning of the accelerator and to insure operation of the machine in any condition, including higher energy. The main outcome of this analysis is that cold measurements on a fraction of the order of one third of the total production, i.e. approximately 400 dipoles, will be sufficient to achieve the above objectives.
WEPLT003	The Study of 2D Sextupole Coupling Resonances at VEPP-4M	resonance, sextupole, coupling, betatron	1819
	V.A. Kvardakov, E. Levichev, A.I. Naumenkov, P.A. Piminov BINP SB RAS, Novosibirsk
	The Study of 2D Sextupole Coupling Resonances at VEPP-4M
WEPLT026	Dynamic Aperture Reduction from the Dodecapole Component in the LHC Main Quadrupoles and its Mechanism.	injection, quadrupole, lattice, resonance	1885
	A.M. Lombardi, O.S. Brüning, S.D. Fartoukh, T. Risselada, F. Schmidt, A. Verdier CERN, Geneva
	The systematic dodecapole component in the Main Quadrupoles of the LHC lattice has a strong influence on the machine dynamic aperture at injection. In this paper we quantify this effect with the help of tracking studies, explain the mechanism for the loss in dynamic aperture and look into potential correction schemes. Finally, we provide an estimate for the maximum allowed systematic dodecapole component in the MQ.
WEPLT066	Beam Dynamics Study for PETRA III Including Damping Wigglers	wiggler, damping, undulator, lattice	1999
	Y.L. Li, K. Balewski, W. Decking DESY, Hamburg
	Damping wigglers will be installed in the storage ring PETRA III to control the beam emittance to 1 nmrad. These wigglers will produce linear and nonlinear perturbations on beam dynamics. A new expanded transport matrix method is developed to solve linear dynamics, and used to match linear lattice functions. The symplectic method is adopted to track particle through the whole ring including the damping wigglers. Halbach?s formulae are used to describe the wiggler field. The main parameters of the wigglers are derived from field calculations. In order to avoid dangerous resonances, tune scanning is implemented to find suitable working points. According to presently known field quality, the nonlinear effects of damping wigglers will not degrade the performance of PETRA III and the dynamic aperture is still larger than the physical aperture.
WEPLT084	Experimental Frequency Maps for the ESRF Storage Ring	kicker, resonance, storage-ring, optics	2050
	Y. Papaphilippou, L. Farvacque, E. Plouviez, J.-L. Revol, A. Ropert ESRF, Grenoble J. Laskar IMCCE, Paris Ch. Skokos Academy of Athens, Athens
	Experimental frequency maps have already revealed many unknown characteristics of the ESRF storage ring non-linear dynamics. In the past year, several efforts were undertaken in order to establish this technique as an operational on-line tool. The acquisition time was significantly reduced by collecting data from a dedicated fast BPM system. The problem of beam decoherence was limited by establishing a method for accurate tune determination in a small number of turns, using the information from all the BPMs around the ring. The possibility to explore the off-momentum dynamics by exciting the beam, with synchronous transverse and longitudinal kicks was also investigated. Finally, measurements of resonance driving term amplitudes and phase advances were used to identify the efficiency of resonance corrections.
WEPLT090	Nonlinear Evolution of the Beam in Phase Space at Elettra	resonance, betatron, beam-losses, coupling	2059
	S. Di Mitri, L. Tosi ELETTRA, Basovizza, Trieste
	Phase space in the Elettra storage ring has been investigated. The beam is kicked and the coordinates of the bunch centroid are acquired for at least 1000 turns. A Hilbert transform has been used to deduce the evolution of beam phase space from position coordinates. Several nonlinear effects have been detected, such as the amplitude dependence of the betatron tune, the presence of high order and coupling resonances. Fixed points have been evidenced as well as the behaviour of the beam in their neighbourhood. Scans in lifetime versus tune confirm the limiting effect of the observed resonances on the region of regular motion.
WEPLT136	Lattice Studies For The MAX-IV Storage Rings	lattice, closed-orbit, octupole, sextupole	2155
	H. Tarawneh, M. Eriksson, L.-J. Lindgren, S. Werin MAX-lab, Lund B. Anderberg AMACC, Uppsala E.J. Wallén ESRF, Grenoble
	The lattice for the future MAX-IV storage rings at MAX-Lab has been studied, The MAX IV facility consists of two similar rings operated at 1.5 GeV and 3 GeV electron energies, The ring consists of 12 supercells each built up by 5 unit cells and matching sections. The high periodicity of the lattice combined with the high gradients in the small gap dipole magnets yield a small emittance of 1 nm.rad, good dynamic aperture and momentum acceptance. In the matching section, a soft end dipole magnet is introduced to reduce the synchrotron radiation power hitting the upstream straight section.
WEPLT147	Lattice Studies for CIRCE (Coherent InfraRed CEnter) at the ALS	lattice, emittance, quadrupole, storage-ring	2182
	H. Nishimura, D. Robin, F. Sannibale, W. Wan LBNL, Berkeley, California
	CIRCE (Coherent InfraRed Center) at the Advanced Light Source is a proposal for a new electron storage ring optimized for the generation of coherent synchrotron radiation (CSR) in the terahertz frequency range. One of the main requirement for this special mode of operation is the capability of the ring of operating at very small momentum compaction values. In this regime, the longitudinal dynamics becomes strongly nonlinear and an accurate control of the higher order energy dependent terms of the momentum compaction is necessary. The lattice for CIRCE allows controlling these terms up to the third order. The paper describes the lattice and presents the calculated performances in terms of momentum acceptance, dynamic aperture, lifetime and momentum compaction tune capabilities.
WEPLT174	Higher Order Hard Edge End Field Effects	multipole, lattice, chromatic-effects, focusing	2236
	J.S. Berg BNL, Upton, Long Island, New York
	In most cases, nonlinearities from magnets must be properly included in tracking and analysis to properly compute quantities of interest, in particular chromatic properties and dynamic aperture. One source of nonlinearities in magnets that is often important and cannot be avoided is the nonlinearity arising at the end of a magnet due to the longitudinal variation of the field at the end of the magnet. Part of this effect is independent of the shape of the end. It is lowest order in the body field of the magnet, and is the result of taking a limit as the length over which the field at the end varies approaches zero. This is referred to as a hard edge" end field. This effect has been computed previously to lowest order in the transverse variables. This paper describes a method to compute this effect to arbitrary order in the transverse variables, under certain constraints. The results of using this hard edge model are compared with performing the computation with finite-length end fields, as well as to the lowest-order hard-edge end field model.
THOACH01	SPEAR3 Commissioning	closed-orbit, storage-ring, feedback, resonance	216
	J.A. Safranek, S. Allison, P. Bellomo, W.J. Corbett, M. Cornacchia, E. Guerra, R.O. Hettel, D. Keeley, N. Kurita, D.J. Martin, P.A. McIntosh, H. Morales, G.J. Portmann, F.S. Rafael, H. Rarback, J.J. Sebek, T. Straumann, A. Terebilo, J. Wachter, C. Wermelskirchen, M. Widmeyer, R. Yotam SLAC/SSRL, Menlo Park, California M.J. Boland, Y.E. Tan ASP, Melbourne J.M. Byrd, D. Robin, T. Scarvie, C. Steier LBNL/ALS, Berkeley, California M. Böge PSI, Villigen H.-P. Chang, C.-C. Kuo, H.-J. Tsai NSRRC, Hsinchu W. Decking DESY, Hamburg M.G. Fedurin, P. Jines LSU/CAMD, Baton Rouge, Louisiana K. Harkay, V. Sajaev ANL/APS, Argonne, Illinois S. Krinsky, B. Podobedov BNL/NSLS, Upton, Long Island, New York L.S. Nadolski SOLEIL, Gif-sur-Yvette A. Ropert ESRF, Grenoble M. Yoon POSTECH, Pohang, Kyungbuk
	Starting in April, 2003, the SPEAR2 storage ring was removed and replaced with a new 500 mA, 3 GeV light source, SPEAR3. The SPEAR2 storage ring had been in use for high energy physics, then synchrotron radiation since 1972. Commissioning of SPEAR3 started on December 8, 2003 and synchrotron radiation will be delivered to the first users on March 8, 2004. SPEAR3 commissioning will be reviewed, including discussion of diagnostics, orbit control, optics correction and high current studies.
	Video of talk
	Transparencies
THPKF026	An Update on the SESAME Light Source	lattice, quadrupole, dipole, sextupole	2323
	D. Einfeld CELLS, Bellaterra (Cerdanyola del Vallès) M. Attal, G. Vignola SESAME, Amman
	During the past three years, the SESAME machine design has been optimised gradually taking into consideration the users demand in the Middle East region. The earlier design concept was to upgrade BESSY I to an energy of 1GeV, now SESAME is a 2.5GeV 3rd generation light source. A recent design review has recommended changing the machine lattice and layout to give greater flexibility for future upgrading and modification, the longest possible beam lines and the longest possible insertion devices, all of that with the limitation of the space available for the machine within the building. By shifting the machine by 6m from the centre of the building (in one direction) it was possible to increase the circumference of the storage ring by 3.6m into 128.4m and beam lines with lengths of 37.7m achieved, while the longest beam line in the old design was only 33.1m, this also increased the total length of the beam lines from 378.2m in the old design into 391.0m. An outline of these optimisations with their influence on the machine output is presented here. Furthermore the beam dynamics, the design of the main components of the storage ring and the first set of beam lines will be discussed.