PAC07 - List of Keywords (dynamic-aperture)

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dynamic-aperture

Paper	Title	Other Keywords	Page
MOOBKI02	DAΦ NE Phi-Factory Upgrade for Siddharta Run	luminosity, sextupole, resonance, injection	66
	M. E. Biagini D. Alesini, D. Babusci, R. Boni, M. Boscolo, F. Bossi, B. Buonomo, A. Clozza, G. O. Delle Monache, T. Demma, G. Di Pirro, A. Drago, A. Gallo, S. Guiducci, C. Ligi, F. Marcellini, G. Mazzitelli, C. Milardi, F. Murtas, L. Pellegrino, M. A. Preger, L. Quintieri, P. Raimondi, R. Ricci, U. Rotundo, C. Sanelli, G. Sensolini, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, S. Tomassini, C. Vaccarezza, M. Zobov INFN/LNF, Frascati (Roma) S. Bettoni CERN, Geneva I. Koop, E. Levichev, P. A. Piminov, D. N. Shatilov, V. V. Smaluk BINP SB RAS, Novosibirsk K. Ohmi KEK, Ibaraki
	An upgrade of the DAΦNE Phi-Factory at LNF is foreseen in view of the installation of the Siddharta detector in 2007. A new Interaction Region suitable to test the large crossing angle and crabbed waist collision schemes* will be installed. Other machine improvements, such as wigglers modifications, new injection kickers and chambers coating will be realized with the goal of reaching luminosity of the order of 10³³/cm²/s. The principle of operation of the new scheme, together with hardware designs and simulation studies, will be presented. *DAPHNE Upgrade Team, "DAPHNE Upgrade for Siddharta run", DAPHNE Tech. Note G-68, LNF-INFN, Dec. 2006
	Slides

MOPAS013	Design Study of a 2-in-1 Large-aperture IR Dipole (D2) for the LHC Luminosity Upgrade	quadrupole, magnet-design, luminosity, dipole	464
	V. Kashikhin A. V. Zlobin Fermilab, Batavia, Illinois
	Funding: This work was supported by the U. S. Department of Energy. After LHC operates for several years at nominal parameters it will need an upgrade to higher luminosity. Replacing the low-beta insertions with a higher performance design based on advanced superconducting magnets is a straightforward step in this direction. One of the approaches being considered for the new LHC IRs is a "dipole-first: option with two separation dipoles placed in front of the focusing quadrupoles. It reduces the number of parasitic collisions with respect to the "quadrupole-first" option and allows independent field error corrections for each beam. Most of key magnet designs for the "dipole-first" option including high-field large-aperture dipoles (D1) and 2-in-1 quadrupoles have already been studied and reported. This paper focuses on design studies of the 2-in-1 separation dipole (D2) located between D1 and the quadrupoles. High operation field of the same polarity in large adjacent apertures imposes limitations on the maximum field, field quality and mechanics for this magnet. This paper analyses possible D2 magnet designs based on Nb3Sn superconductor and compares them in terms of the aperture size, maximum field, field quality and Lorents forces in the coil.

TUPMN013	Dynamic Multipole Shimming of the APPLE Undulator UE112	undulator, multipole, simulation, permanent-magnet	941
	J. Bahrdt W. Frentrup, A. Gaupp, M. Scheer, G. Wuestefeld BESSY GmbH, Berlin
	The dynamic off axis field integrals of the BESSY UE112 are of the order of 3 Tmm. They reduce the dynamic aperture significantly which is not tolerable for top-up operation. The dynamic multipoles have successfully been shimmed for the elliptical mode using distributed Fe-shims. In the inclined mode the multipoles are minimized actively with rotatable permanent magnets which are adjusted dependent on gap and phase position. The dynamic properties of the unshimmed and the shimmed device have been simulated using an analytic model for the field description and a generating function algorithm for tracking.

TUPMN060	A Low Emittance Lattice Design for HLS Storage Ring	emittance, lattice, radiation, storage-ring	1064
	L. Wang G. Feng, W. Li, L. Liu, H. Xu USTC/NSRL, Hefei, Anhui S. C. Zhang USTC, Hefei, Anhui
	Lower beam emittance is the most effective measure to higher brilliance of light source. To enhance performance of HLS ring, a new low emittance lattice was studied and introduced in this paper. The scale of new lattice is designed according to the current ground settlement of HLS ring, but the focusing structure and mangets were changed. The new designed lattice has two operation mode, low emittance mode and low momentum compaction mode. In this paper, the linear lattice function and dynamic aperutre of the new designed lattice was briefly introduced. Caculation results showed that, after upgrade, the brilliance of HLS storage ring can approach the level of third order light source.

TUPMN072	Current Status of Lattice Design and Accelerator Physics Issues of the 3 GeV Taiwan Synchrotron Light Source	emittance, lattice, dipole, synchrotron	1085
	C.-C. Kuo H.-P. Chang, H. C. Chao, P. J. Chou, W. T. Liu, G.-H. Luo, H.-J. Tsai, M.-H. Wang NSRRC, Hsinchu
	In the past years, we have been conducting a design work for a synchrotron light facility with low emittance storage ring in the intermediate energy range in NSRRC. A number of design options with different lattice structure types, circumferences, etc., are compared. We present one design case with 24-cell DBA structure and 486 m circumference. The associated accelerator physics issues are discussed.

TUPMN096	New Lattice Design for APS Storage Ring with Potential Tri-fold Increase of the Number of Insertion Devices	lattice, emittance, injection, dipole	1139
	V. Sajaev M. Borland, A. Xiao ANL, Argonne, Illinois
	Funding: Work supported by the U. S. Department of Energy, Office of Science, Basic Energy Sciences, under Contract No. DE-AC02-06CH11357 APS has recently held a round of discussions on upgrade options for the APS storage ring. Several options were discussed that included both storage ring and energy-recovery linac options. Here we present a storage ring lattice that fits into the APS tunnel and has a number of significant improvements over the existing storage ring. The present APS lattice has 40-fold symmetry with each sector having one 5-m-long straight section for insertion device (ID) placement. Each sector also provides one beamline for radiation from the bending magnet. The upgrade lattice preserves locations of the existing insertion devices but provides for increased ID straight section length to accommodate 8-m-long insertion devices. This lattice also decreases emittance by a factor of two down to 1.6 nm rad. And last but not least, it provides two additional 2.1-m-long ID straight sections per sector with one of these straight sections being parallel to the existing bending magnet beamline. We also present dynamic aperture optimization, lifetime calculations, and other nonlinear-dynamics-related simulations.

TUPMN111	A Low Emittance Lattice for the Advanced Light Source	sextupole, emittance, lattice, quadrupole	1170
	H. Nishimura S. Marks, D. Robin, D. Schlueter, C. Steier, W. Wan LBNL, Berkeley, California
	Funding: Work supported by the U. S. Department of Energy under Contract No. DE-AC03-76SF00098 The possibility exists of achieving significantly lower emittances in an electron storage ring by increasing its horizontal betatron tune. However, existing magnet locations and strengths in a given ring may be inadequate to implement such an operational mode. For example, the ALS storage ring could lower its emittance to one third of the current value by increasing the horizontal tune from 14.25 to 16.25. However, this would come with the cost of large chromaticities that could not be corrected with our existing sextupole magnets. We discuss such operational issues and possible options in this paper.

TUPMS043	Design of a 2.1 GeV Electron Storage Ring	simulation, emittance, impedance, vacuum	1284
	R. A. Bosch
	Funding: This research was supported by National Science Foundation Grant no. DMR-0537588. A 2.1 GeV electron storage ring can serve as a third-generation light source for photon energies of 1-2000 eV. We design a ring with emittance of 1.5 nm-rad, circumference of 215 m, and twelve 5.5 m long straight sections. With a 100 MHz radiofrequency (rf) system, the computed Touschek current-lifetime product is 2800 mA-hr. Two passive fifth-harmonic cavities may be used to suppress parasitic coupled-bunch instabilities while increasing the bunchlength and lifetime by a factor of four. For stable operation with ring currents up to 600 mA, microwave-instability simulations indicate that the reduced longitudinal impedance should not exceed 1.5Ω.

TUPAN049	Low Emittance Lattices and Final Focus Design for the SuperB Project	sextupole, lattice, emittance, betatron	1499
	Y. Ohnishi M. E. Biagini, P. Raimondi INFN/LNF, Frascati (Roma) Y. Cai, J. Seeman, M. K. Sullivan, U. Wienands SLAC, Menlo Park, California A. Wolski Liverpool University, Science Faculty, Liverpool
	For the SuperB project* very low emittances (horizontal < 1 nm) and small beta functions at the Interaction Points are required to achieve the design luminosity of 10³⁶/cm²/s. Low emittance lattice have been designed, using the PEP-II magnets, for the two rings of 4 and 7 GeV, which will have the same emittances and damping times. A new Final Focus section has also been designed to get the strong focusing at the Interaction Point, at the same time providing local correction of the high chromaticity and exploiting the large crossing angle and crabbed waist concepts. Lattice features and chromaticity correction schemes will be discussed. Dynamic apertures, with damping wigglers similar to the ILC ones, will also be presented. * P. Raimondi, "New Developments for SuperB Factories", Invited talk, this Conference

TUPAS056	Compensation Strategy for Optical Distortions Arising from the Beam-Beam Interaction at CESR	electron, positron, optics, controls	1778
	J. A. Crittenden M. G. Billing CESR-LEPP, Ithaca, New York
	Funding: National Science Foundation grant PHY-0202078 Following two decades of operation at 5 GeV beam energy for studies of bottom quark bound states, the Cornell Electron Storage Ring (CESR) converted to 2 GeV operation in 2001 for the purpose of investigating bound states of charm quarks. This reduction of beam energy resulted in increased relative contributions of the beam-beam force. The beam-beam interaction has been found to have considerable consequences for the optics and for the injection aperture. We describe recent developments in our modelling of the beam-beam interaction, experimental validation techniques, and investigations into compensation strategies.

TUPAS099	A Near-Integer Working Point for Polarized Protons in the Relativistic Heavy Ion Collider	resonance, proton, luminosity, polarization	1871
	C. Montag M. Bai, J. Beebe-Wang, M. Blaskiewicz, R. Calaga, W. Fischer, A. K. Jain, Y. Luo, N. Malitsky, T. Roser, S. Tepikian BNL, Upton, Long Island, New York
	Funding: Work performed under the auspices of the US Department of Energy. To achieve the RHIC polarized proton enhanced luminosity goal of 150*10³⁰ cm^-2 sec^-1 on average in stores at 250 GeV, the luminosity needs to be increased by a factor of 3 compared to what was achieved in 2006. Since the number of bunches is already at its maximum of 111, limited by the injection kickers and the experiments' time resolution, the luminosity can only be increased by either increasing the bunch intensity and/or reducing the beam emittance. This leads to a larger beam-beam tuneshift parameter. Operation during 2006 has shown that the beam-beam interaction is already dominating the luminosity lifetime. To overcome this limitation, a near-integer working point is under study. We will present recent results of these studies.

THPMN116	Frequency Map Studies for the ILC Damping Rings	lattice, resonance, sextupole, quadrupole	2987
	I. Reichel
	Funding: This work was supported by the U. S. Department of Energy under Contract No. DE-AC02-05CH11231. Designing a lattice with sufficient dynamic aperture for the ILC Damping Rings is very challenging as the lattice needs to provide a small equilibrium emittance and at the same time a large aperture for the injected beam including a large momentum acceptance. In addition outside constraints have forced layout changes in the damping ring. Some of the layout changes had an impact on the dynamic aperture. In order to better understand the changes in dynamic aperture, frequency maps are studied. Those studies can help in identifying the reason for the changed dynamic aperture and in finding a good location for the betatron tunes and determining an upper limit for the chromaticities. A summary of recent studies and suggestions improving the dynamic aperture by choosing a different tune are presented.

THPAN028	HESR Lattice with Non-similar Arcs for the Stochastic Cooling	lattice, quadrupole, pick-up, kicker	3289
	Y. Senichev
	The advanced HESR lattice with two arcs having the identical layout and the different slip factors are developed. The conception of arcs with three families of quadrupole allows easy adjusting the imaginary transition energy in one arc and the real transition energy in another arc with the absolute value close to the beam energy in whole required region from 3.0 GeV to 14 GeV. The arcs have the special feature, when the high order non-linearities are fully compensated inside of each arc, and therefore the dynamic aperture of the whole machine is conserved. We consider and compare two lattices with the same absolute value of transition energy: the current lattice with the negative momentum compaction factor in both arcs and the lattice having the negative and positive momentum compaction factors in different arcs correspondingly. Simultaneously we analyzed the 4 and 6 fold symmetry arcs machine. It allows making the conclusion that the 4 fold symmetry lattice is more suitable to get the required slip factors. At the lowest energy 3 GeV, the absolute value of slip factor in the imaginary and the real arc is related as ~0.09/0.02 correspondingly. For the higher beam energy this ratio is much bigger.

THPAN042	Recent Progress of Optics Correction at KEKB	sextupole, emittance, resonance, optics	3321
	A. Morita H. Koiso, Y. Ohnishi, K. Oide KEK, Ibaraki
	In recently KEKB operation, we have to tune the operation parameters during about one week in order to recover the peak performance after the optics correction. This wrong reproducibility of the luminosity is a significant problem for the integrated luminosity of the physics run. In this paper, we present the progress of the optics correction to improve the reproducibility of the machine performance.

THPAN051	Update on the ILC DR Alternative Lattice Design	lattice, damping, sextupole, wiggler	3342
	Y. Sun J. Gao IHEP Beijing, Beijing Z. Y. Guo PKU/IHIP, Beijing
	In order to reduce the cost for ILC damping rings, an alternative lattice which is different from the baseline configuration design has been designed previously with modified FODO arc cells, and the total quadrupole and sextupole number has been reduced largely, compared with the baseline design. At the same time, to decrease the total cost involved in constructing access shafts needed to supply power, cryogenics etc. for the wigglers and other systems, the number of wiggler sections is decreased from 8 to 4, and further to 2. However, the momentum compaction of this lattice can not be tuned freely. In this paper, a new ILC damping ring lattice design with a variable momentum compaction will be presented, followed by the single particle dynamics associated studies. *ypsun@ihep.ac.cn

THPAN055	Theoretical Study of Medium Emittance Lattice at HLS	lattice, emittance, synchrotron, synchrotron-radiation	3351
	H. Hao G. Feng, W. Li, L. Wang, X. Wang, H. Xu USTC/NSRL, Hefei, Anhui S. C. Zhang USTC, Hefei, Anhui
	Funding: Supported by National Natural Science Foundation of China, No. 10175062 & No.17175100 A method of injection analysis of small electron storage ring is introduced, and several medium emittance lattices are proposed. By analyzing the injection, working point of the lattice is selected at the vicinity of half integer resonance lines, and emittance is around 60nmrad, the linear and nonlinear properties can be satisfied for injection and store. LIU Zu-Ping, Li Wei-Min. Progress of the NSRL Phase Two Project. In proceedings of the Second Asia Particle Accelerator Conference, Beijing, China, 2001, 235-238

THPAN096	A 1-nm Emittance Lattice for the Advanced Photon Source Storage Ring	lattice, emittance, damping, undulator	3447
	A. Xiao M. Borland, V. Sajaev ANL, Argonne, Illinois
	Funding: Work supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. We present a triple-bend lattice design that uses the current APS tunnel. The new lattice has a 1 nm-rad effective emittance at 7 GeV. A forty-period symmetric optics is presented. For the benefit of some X-ray user experiments, an optics with four special straight sections of one-third the beam size of normal sections was investigated as well. The associated nonlinear optical difficulties are addressed and simulation results are presented.

THPAN097	International Linear Collider Damping Ring Lattice Design	lattice, injection, damping, emittance	3450
	A. Xiao L. Emery ANL, Argonne, Illinois
	Funding: Work supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. We present a lattice design based on the theoretical-minimum-emittance (TME) cell for the International Linear Collider (ILC0 6.6-km 5-GeV damping ring. Several areas are discussed: momentum compaction, lattice layout, injection and extraction, circumference adjusters, phase adjuster, and dynamic aperture calculation with multipole errors.

THPAN109	A New Lattice Design for a 1.5 TeV CoM Muon Collider Consistent with the Tevatron Tunnel	lattice, collider, sextupole, quadrupole	3483
	P. Snopok M. Berz MSU, East Lansing, Michigan C. Johnstone Fermilab, Batavia, Illinois
	A recent effort is underway to design an efficient match of a Muon Collider to the Fermilab site, potentially using the Tevatron tunnel after decommissioning. This work represents a new design for such a collider with emphasis on shortened IR and systematic high-order correction and dynamics studies. With a 1 cm β^*, simultaneous control of geometric and chromatic aberrations is critical and can only be achieved through the deliberate addition of nonlinear fields in the Interaction Region itself. This work studies both the correction schemes and the unavoidable impact of high-order correctors – sextupoles, octupoles and even duodecapoles – located in the Interaction Region close to the low-beta quadrupoles or focusing elements. This study proposes and systematically addresses the aberrations for different systems of nonlinear correctors and optimizes performance of an advanced IR.

THPAN114	Simulations of Beam-wire Experiments at RHIC	simulation, resonance, beam-losses, injection	3492
	T. Sen H. J. Kim Fermilab, Batavia, Illinois
	We report on simulations of beam-beam experiments performed at RHIC in 2006. These experiments were designed to observe the influence of a single parasitic interaction on beam quality. Several observables such as tunes, emittances and losses were simulated with the weak-strong code BBSIM. These simulation results are compared to observed values. Simulations of the wire compensation experiment to be carried out in RHIC are also shown.

FRPMN011	Studies of Dipole Field Quality for the Beta-Beam Decay Ring	dipole, multipole, sextupole, resonance	3904
	A. Chance J. Payet CEA, Gif-sur-Yvette
	Funding: European Community under the FP6 - Research Infrastructure Action - Structuring the European Research Area - EURISOL DS Project Contract no. 515768 RIDS. The aim of the beta-beams is to produce highly energetic beams of pure electron neutrino and anti-neutrino, coming from beta-decays of the ¹⁸Ne¹⁰⁺ and ⁶He²⁺, both at γ=100, directed towards experimental halls situated in the Frejus tunnel. The high intensity ion beams are stored in a ring until the ions decay. The beta decay products have a magnetic rigidity different from the one of the parent ions and are differently deflected in the 6T superconducting dipoles. Consequently, all the injected ions are lost anywhere in the ring, generating a high level of irradiation. So, the dipole apertures need to be large enough to avoid the decay products hitting their walls, which may worsen the field quality. A study on its tolerances has been carried out. Since the decay ring has to accept the beam during a large number of turns, the chosen criteria is the size of the dynamic aperture that the multipolar defects in the dipoles may shrink. Tolerances on the systematic and random errors of these defects have been investigated. In order to relax the tolerances, a routine was written which enlarges automatically the dynamic aperture in presence of field errors.

FRPMS099	The Poincare Map, Lie Generator, Nonlinear Invariant, Parameter Dependance, and Dynamic Aperture for Rings	lattice, controls, optics, sextupole	4315
	J. Bengtsson
	Funding: Work supported by U. S. DOE, Contract No. DE-AC02-98CH10886. In earlier work related to the NSLS-II project we have outlined a control theory approach for the dynamic aperture problem. In particular, an algorithm for the joint optimization of the Lie generator and the working point for the Poincare map. This time we report on how the Lie generator provides guidelines on acceptable magnitudes for e.g. the intrinsic nonlinear effects from insertion devices, and the nonlinear pseudo-invariant can be used to optimize the dynamic aperture. We also show how a polymorphic beam line class can be used to study the parameter dependance and rank conditions for control of optics and dynamic aperture. bengtsson@bnl.gov

FRPMS111	Dynamic Aperture Evaluation at the Current Working Point for RHIC Polarized Proton Operation	sextupole, resonance, multipole, dipole	4363
	Y. Luo M. Bai, J. Beebe-Wang, W. Fischer, A. K. Jain, C. Montag, T. Roser, S. Tepikian, D. Trbojevic BNL, Upton, Long Island, New York
	Funding: Work supported by U. S. DOE under contract No DE-AC02-98CH10886. To further improve the the polarized proton (pp) luminosity in the Relativistic Heavy Ion Collider, the beta functions at the two interaction points (IPs) will be reduced from 1.0 m to 0.9m in 2007. In addition, it is planned to increase the bunch intensity from 1.510¹¹ to 2.010¹¹. To accommodate these changes, the nonlinear chromaticities and the third resonance driving term should be corrected. In 2007, the number of the arc sextupole power supplies will be doubled from 12 to 24, which allows nonlinear chromaticity correction. With the updated field errors in the interaction regions (IRs), detailed dynamic aperture studies are carried out to optimize the nonlinear correction schemes, and increase the available tune space in collision.