| Paper | Title | Page |
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| THPMR001 | Online Suppression of the Sextupole Resonance Driving Terms in the Diamond Storage Ring | 3381 |
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Suppression of the sextupole resonance driving terms (RDTs) is a widely used technique for optimising the theoretical on and off-momentum dynamic aperture for electron storage rings. Recently, this technique was applied online to the Diamond storage ring, with suppression of individual RDTs achieved via a sextupole family to RDT response matrix*. In this paper we present recent studies of the method, in which the ability to improve the lifetime and injection efficiency are investigated. An extension of the technique is investigated by combining it with the Robust Conjugate Direction Search (RCDS) optimisation algorithm**.
*J. Bengtsson, et al., Phys. Rev. ST Accel. Beams 18, 074002, (2015). **X. Huang, et al., Nucl. Instrum. Methods Phys. Res. Sect. A 726, 77, (2013). |
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| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR001 | |
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| THPMR002 | Optics Corrections with LOCO in the Fermilab Booster | 3385 |
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Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. The optics of the Fermilab Booster has been corrected with LOCO (Linear Optics from Closed Orbits). However, the first corrections did not show any improvement in capture efficiency at injection. A detailed analysis of the results showed that the problem lay in the MADX optics file. Both the quadrupole and chromatic strengths were originally set as constants independent of beam energy. However, careful comparison between the measured and calculated tunes and chromatcity show that these strengths are energy dependent. After the MADX model was modified with these new energy dependent strengths, the LOCO corrected lattice has been applied to Booster. The effect of the corrected lattice will be discussed here. |
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| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR002 | |
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| THPMR003 | Failure Modes and Beam Losses Studies in ILC Bunch Compressors and Main Linac | 3388 |
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| Proposed International linear collider (ILC) involves high average beam power. Dealing with high average beam power and smaller beam sizes result in stringent tolerances on beam losses and therefore, extensive studies are required to investigate every possible scenarios that lead to beam losses. In this paper we discuss beam losses due to failure of critical elements in beamline for ILC bunch compressors and main linac. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR003 | |
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| THPMR004 | Design of a Compact ion Beam Transport System for the BELLA Ion Accelerator | 3391 |
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Funding: This work was supported by LDRD funding from Lawrence Berkeley National Lab, provided by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The Berkeley Lab Laser Accelerator (BELLA) Center hosts a Ti:sapphire CPA laser providing laser pulses at petawatt-level peak power with a repetition rate of 1 Hz. High irradiances of 1022 W/cm2 can be achieved with a short focal length beamline when the laser is focused to a spot of w0 < 5 um. Under this condition, theoretical and particle-in-cell (PIC) simulations have shown that protons and helium ions at energies up to several hundred MeV/u can be expected from the interaction between BELLA laser pulses and different targets. High ion energies*, low energy spread with high controllability and stability, a new generation of ion accelerators using high performance laser-driven ion beam has numerous potential applications such as injectors for conventional accelerators, radiation therapy, as well as high energy density laboratory physics and material science studies. We will present a preliminary ion optics design to collect, transport, and focus the ions generated from the laser-driven ion accelerator, and beam dynamics results using the ion distribution from the PIC simulation. * S.S. Bulanov et al, Physical Review Special Topics: Accelerators and Beams 18, 061302 (2015). |
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| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR004 | |
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| THPMR005 | Systematic Errors Investigation in Frozen and Quasi-Frozen Spin Lattices of Deuteron EDM Ring | 3394 |
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| The search for the electric dipole moment (EDM) in the storage ring raises two questions: how to create conditions for maximum growth of the total EDM signal of all particles in bunch, and how to differentiate the EDM signal from the induced magnetic dipole moment (MDM) signal. The T-BMT equation distinctly addresses each issue. Because the EDM signal is proportional to the projection of the spin on the direction of the momentum, it is desirable to freeze the spin direction of all particles in a bunch along momentum. It can be successfully implemented in the Quasi Frozen (QFS) and Frozen (FS) Spin structures. However, in case of magnet misalignments, the induced MDM signal may arise in the same plane as the EDM signal and thereby prevent its registration. In this paper, we analyze the effect of errors together with the spin-tune decoherence of all particles in the bunch for FS and QFS options. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR005 | |
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| THPMR006 | Muon Beam Tracking and Spin-Orbit Correlations for Precision g-2 Measurements | 3397 |
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| The main goal of the Muon g-2 Experiment (g-2) at Fermilab is to measure the muon anomalous magnetic moment to unprecedented precision. This new measurement will allow to test the completeness of the Standard Model (SM) and to validate other theoretical models beyond the SM. The close interplay of the understanding of particle beam dynamics and the preparation of the beam properties with the experimental measurement is tantamount to the reduction of systematic errors in the determination of the muon anomalous magnetic moment. We describe progress in developing detailed calculations and modeling of the muon beam delivery system in order to obtain a better understanding of spin-orbit correlations, nonlinearities, and more realistic aspects that contribute to the systematic errors of the g-2 measurement. Our simulation is meant to provide statistical studies of error effects and quick analyses of running conditions for when g-2 is taking beam, among others. We are using COSY, a differential algebra solver developed at Michigan State University that will also serve as an alternative to compare results obtained by other simulation teams of the g-2 Collaboration. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR006 | |
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| THPMR008 | Experimental Crosscheck of Algorithms for Magnet Lattice Correction | 3400 |
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Funding: Work supported by DOE contract DE-AC02-98CH10886 Performance, capabilities and limitations of various algorithms for linear magnet optics correction have been studied experimentally at NSLS-II. For the crosscheck, we have selected 4 algorithms based on turn-by-turn beam position analysis: weighted correction of betatron phase and amplitude, independent component analysis, model-independent analysis, and driving-terms-based linear optics characterization. A LOCO algorithm based on closed orbit measurement has been used as a reference. For the correction, either iterative solving of linear problem (matrix inversion with singular-value decomposition) or variational optimization has been used. For all the algorithms, accuracy limitations and convergence of linear lattice correction are discussed. |
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| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR008 | |
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| THPMR010 | Electron Polarization in the eRHIC Ring-Ring Design | 3403 |
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Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. High electron beam polarization (70-80%) is required in the future electron-ion collider eRHIC over the whole electron beam energy range from 5 GeV to 20 GeV. This paper analyzes important aspects for achieving a high electron polarization level in the ring-ring design option of eRHIC and presents the design of spin rotators required to generate the longitudinal polarization orientation at the interaction point. Experiment considerations require bunch spin patterns with both spins up and down. A highly polarized beam will be produced by a photo-injector, accelerated to full collision energy by an injector accelerator and injected into the storage ring. Beam depolarization time in the storage ring has to be minimized in the presence of spin rotators, detector solenoid and damping wiggler, which establishes specific requirements for the ring lattice. |
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| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR010 | |
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| THPMR011 | Injection Dynamics for Sirius Using a Nonlinear Kicker | 3406 |
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| The concept of injection using a single nonlinear kicker has been proposed and tested in several existing storage rings with reduction in the stored beam oscillations during the accumulation process. Despite the good results, this scheme has not yet been adopted for routine operation in these machines due to the reduced injection efficiency. The main cause for reduction in efficiency is precisely the nonlinearity of the kick at the injected beam position and the generally large injected beam size. In this paper we study the injection dynamics in the Sirius storage ring where beam accumulation is based only on the use of a nonlinear kicker. The whole injection system has been optimized from the start for high injection efficiency. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR011 | |
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| THPMR012 | Optimization of Nonlinear Dynamics for Sirius | 3409 |
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| In this work we describe the optimization of the non-linear dynamics for the Sirius storage ring. The strong sextupoles of the lattice, necessary to correct the linear chromaticities, generate higher order terms in the tune-shifts with amplitude and energy, which may result in a large tune footprint for the machine. The configuration the sextupole families found that wraps this tune footprint and thus avoids dangerous resonances was achieved with minimization of Hamiltonian driving terms and tracking-based multi-objective algorithms include realistic values of misalignment and excitation errors of the magnets, orbit correction, insertion devices fields and real vacuum chamber apertures. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR012 | |
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| THPMR013 | A New Optics for Sirius | 3413 |
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| We report on the latest optics modifications for the 3 GeV Sirius electron storage ring presently under construction at the Brazilian Synchrotron Light Laboratory, LNLS. Although the basic parameters are set and frozen, improvements in the magnetic lattice and beam optics are still being implemented. In particular, the central dipole in the 5BA cell has been replaced by an all-permanent-magnet dipole with a thin superbend in the center with peak magnetic field of 3.2 T and the operation mode has now symmetry 5, with 15 low βx straight sections and 5 high βx sections. The 3 GeV ring bare lattice emittance is now 0.25 nm.rad. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR013 | |
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| THPMR014 | Core-halo Limits and Beam Halo-formation Dynamic | 3417 |
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In high intensity linear accelerators, space charge related instabilities and effects are the cause of emittance increase and beam losses. The mechanism of halo formation due to a mismatched beam causing parametric resonances and energy transfer between phase-spaces is one of them. The previously defined one dimensional core-halo limit [1][2] was extended to two dimensional distributions [3][4]. This halo characterization method is applied to a classical case of transport for halo formation studies: the transport of a mismatched beam. Our method provides a core-halo limit that matches the expected halo formation mechanism with a very good precision.
* Appl. Phys. Lett. 104, 074109 (2014) ** Phys. Plasmas, 22, 083115, (2015) *** IPAC (2015) MOPWA010 **** TBP |
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| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR014 | |
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| THPMR015 | RCDS Optimizations for the ESRF Storage Ring | 3420 |
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The Robust Conjugate Direction Search (RCDS)* optimizer is applied for online optimizations of the ESRF accelerators. This paper presents the successful application of the algorithm in reducing vertical emittance, improving injection efficiency and increasing lifetime. A new set of sextupole settings to increase chromaticity has been obtained with lifetimes comparable to the existing one. This allows to run with double current in a single bunch, and unifies the optics for few bunch (except 4x10 bunches) and multi-bunch modes.
* X. Huang, J. Corbett, J. Safranek, J. Wu, "An algorithm for online optimization of accelerators", Nucl. Instr. Methods, A 726 (2013) 77-83. |
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| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR015 | |
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| THPMR016 | Horizontal Phase Space Shaping for Optimized Off-axis Injection Efficiency | 3424 |
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| With the introduction of top-up operation at the ESRF it becomes important to reduce as much as possible any kind of perturbation seen by the users during injection. For this purpose, a novel technique to improve injection efficiency by shaping the horizontal beam phase space to better match the storage ring acceptance and hence reduce the duration of injections was developed. Theoretical concept, simulations and first experimental results are presented. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR016 | |
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| THPMR017 | Resonance Island Experiments at BESSY II for User Applications | 3427 |
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Beam storage close to a tune resonance (Qx = 1/3, 1/4) can generate resonance island buckets in the x,x' phase space providing a second stable island orbit winding around the standard orbit. Experiments with such an operation mode have been conducted at BESSY II and the Metrology Light Source (MLS)*,**. The two orbits are well separated, with good life time and stability. Such operation mode will offer additional operation flexibility and allows users to choose their radiation source point from one or the other orbit. It has the potential to fulfill simultaneously conflicting user demands, e.g., high vs. low beam current and single or few bunch filling vs. multibunch filling. We discuss the required beam optics setup and present successful measurements taken at photon beamlines at BESSY II.
* P. Goslawski et al., "Bunch Separation by Transverse Resonance Island Buckets", ESLS XXIII Workshop, 2015, Villigen, Switzerland. ** M. Ries et al., Proc. IPAC 2015, Richmond, USA, MOPWA021. |
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| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR017 | |
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| THPMR018 | Ion-Optics of Antiproton Separator at FAIR | 3431 |
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| In the framework of antiproton program at FAIR project, the large acceptance antiproton separator is dedicated for the effective separation of the secondary antiprotons from the primary protons and the secondary beams of other particle species and subsequent transportation to the Collector Ring (CR). Here we present the latest ion-optical layout of the antiproton separator and possible second-order correction scheme as well. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR018 | |
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| THPMR020 | Bunch Purity Measurements at PETRA III | 3434 |
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| Since 2010 the 6 GeV synchrotron light source PETRA III is in operation. With a horizontal emittance of 1.2 nm*rad, a coupling of typically 1% and a total beam current of 100 mA the machine provides extremely brilliant synchrotron radiation for the users. For time-resolved measurements a filling pattern with 40 equidistant bunches with equal charge is used. To measure parasitic bunches between the main bunches two beamlines are equipped with avalanche photodiodes (APD) and time to digital converters (TDC) electronics. Besides parasitic bunches originating from the pre-accelerators of PETRA III it has been observed that initially empty buckets following the main bunch are populated. Measurements of the effect will be discussed and compared with simulations. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR020 | |
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| THPMR021 | Bmad Model of COSY, Status and Progress | 3437 |
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| Abstract The COSY in Jülich is a versatile machine with a long history of polarized proton acceleration. A new model of COSY based on the Bmad library was developed to simulate beam and spin dynamics. Original methods of lattice design, notably multi-objective lattice optimization, were explored. This contribution presents the status and development steps of the Bmad model of COSY. Some of the latest simulations will also be discussed. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR021 | |
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| THPMR022 | Non-linear Optimization of Storage Ring Lattice for the SPring-8 Upgrade | 3440 |
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| A project of upgrading the SPring-8 facility is ongoing to convert the present storage ring to a high-coherence hard X-ray source (SPring-8-II). To achieve the emittance value of less than 0.2 nmrad at 6 GeV, we adopted a 5-bend achromat lattice with dipoles having longitudinal field gradient. In this lattice the betatron phase between the two dispersion arcs was set to (2n+1)PI to suppress dominant harmful effects of chromaticity-correcting sextupoles. By detuning this phase, optimizing sextupole strengths in a cell and introducing octupoles, we obtained a sufficient dynamic aperture (DA) for beam injection even for the symmetry-broken ring having four long straight sections and a high-beta injection section. However, the off-momentum behavior such as the non-linear chromaticity still needs to be optimized to achieve the momentum acceptance (MA) of 3% or larger. We have thus been investigating the possibility to increase both the DA and MA by introducing several phase-matched sextupole pairs. The presentation will report the obtained results by this approach. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR022 | |
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| THPMR025 | Simulation of Beam Behavior Caused by Odd Harmonics of Beam Loading in J-PARC RCS | 3443 |
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| The J-PARC RCS accelerates 2 bunches at the harmonic number 2. The major Fourier component of the beam current is even harmonics. However, the odd harmonics grow under some conditions even though they are very small amplitude at the beginning. We describe the the particle tracking simulation results for the odd harmonic beam loading effect in the RCS. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR025 | |
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| THPMR026 | SESAME Storage Ring Beam Dynamics in View of the Results of its Magnet Measurements | 3446 |
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| SESAME storage ring magnets have been recently constructed and measured. The storage ring beam dynamics is reviewed in this article in view of these results. Moreover it is shown how the optical impact of dipoles main field errors is more mitigated by sorting dipoles in the storage ring in addition to the alignment optimization method suggested by magnetic measurement outcome. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR026 | |
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| THPMR030 | Results of the Use of Axisymmetric RF Focusing in Proton Linacs at Energies up to 7 MeV | 3449 |
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| During a few decades axisymmetric RF structures with a focusing by means of nonsynchronous spatial harmonics of electromagnetic field are offered instead of proven RFQ. An effectiveness of these structures in the energy range up to 2 MeV was shown in a number of papers. An effectiveness of these structures in the energy range up to 7 MeV is considered in this paper. Results of an analytical investigation and a numerical simulation of self-consistent proton dynamics are presented and discussed. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR030 | |
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| THPMR031 | Turn-by-Turn Measurements for Beam Dynamics at Vepp-5 Damping Ring | 3452 |
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| Preinjector complex VEPP-5 is being constructed for high rate production and acceleration of electrons and positrons beams up to energy 510 MeV. Both kinds of particles accumulated in the damping ring and after achieving of needed intensity the beams would be transported alternatively to VEPP-3/VEPP-4M or to BEP/VEPP-2000 colliders. At this paper basic parameters of damping ring presented. All measurements were carried out for electron beam with energy 385 MeV. For turn-by-turn measurements 12 beam position monitors were used. In order to improve precision of measured value NAFF algorithm was applied. For measurements of longitudinal beam profile optical phi-dissector was used. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR031 | |
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| THPMR032 | Dynamical Aperture Control in Accelerator Lattices With Multipole Potentials | 3455 |
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| We apply two analytical methods to control accelerator dynamic aperture (DA) with multipole potentials. Both methods assume that accelerator model can be represented as a product of unperturbed and perturbed exponential operators with exponent of perturbed operator given as formal power series in perturbation parameter and known dependence of series coefficients on lattice parameters such as multipole strength distribution. Normal form method can be applied to the above representation and then lattice parameters are used to control normal form Hamiltonian coefficients. Hamiltonian control can be used to compute control term and lattice parameters are then fitted to approximate corresponding controlled operator. Theoretical results as well as model examples are presented. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR032 | |
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| THPMR034 | Simulation of Single Particle Dynamics in a Compact Planar Wiggler | 3458 |
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In this report a description of a simple approach how to simulate a single particle track in a 3D magnetic field using Radia code is presented. Such a simulation maybe useful in order to briefly estimate in a short time the beam dynamics in the magnetic field produced by means of different types of the magnet devices. As an example, a low energy relativistic electron tracking* is performed in a compact 30 cm planar wiggler which produced ~0.4 T magnetic field. The changes of the electron entrance point and motion direction are also available. This simulation is carried out using three-dimensional magnetostatic code - Radia**, where the 4th order Runge-Kutta method was implemented for the trajectory calculations. Since Radia is the Mathematica add-on then a small Wolfram Language code is developed to create the wiggler model, to calculate the electron trajectory and to illustrate the simulation results.
* Knyazik A. et al. Status of UCLA helical permanent-magnet undulator // Proc. of PAC, Canada, WE5RFP076 (2009) 2441 ** http://www.esrf.eu/Accelerators/Groups/InsertionDevices/Software/Radia |
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| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR034 | |
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| THPMR035 | Low Horizontal Beta Optics for ALBA | 3461 |
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| The ALBA insertion device beamlines have a horizontal and vertical rms source size of 130 and 5.5 microns. Protein crystallography beamlines (Xaloc) would benefit from a reduction of the horizontal and increase of the vertical beam size, to gain spatial resolution and avoid anisotropy effects. A modified lattice with horizontal and vertical beam size of 74 and 9 microns has been setup and tested, breaking the ring symmetry, with different setting of the six neightbouring quadrupoles at each side of the Xaloc insertion device. Such configuration keeps the nominal emittance almost unvaried and the working point is recovered by small changes in the quadrupole strengths of the four symmetric matching sections. A dedicated setting of the nine available sextupole families has been obtained by numerical optimization of the dynamical apertures and tune shifts. The lattice settings have been satisfactorily tested. The measured lifetime is reduced a factor two and the injection efficiency decreases to 60%. Finally, the option of increasing the number of sextupole families, to recover the dynamic aperture and guarantee the injection efficiency, has been studied. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR035 | |
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| THPMR036 | Improved Methods for the Measurement and Simulation of the CERN SPS Non-linear Optics | 3464 |
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| Good knowledge of the non-linear properties of the SPS lattice is crucial for modelling and optimising the machine performance in the presence of collective effects leading to incoherent tune spreads such as space charge, e-cloud and beam coupling impedance. In view of the LHC injectors upgrade (LIU) project and the future SPS operation in a regime dominated by such collective effects, detailed measurements of the SPS non-linear chromaticity and detuning with amplitude have been performed for the two optics configurations presently available for LHC type beams. The measurement results are used to fit systematic multipole components to the main magnets of the SPS MADX model as a basis for the non-linear machine model that can be used for beam dynamics simulations. The implications for the operation of the SPS with the LIU beam parameters are discussed. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR036 | |
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| THPMR037 | Observations of Resonance Driving Terms in the LHC during Runs I and II | 3468 |
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| Future operations of the LHC will require a good understanding of the nonlinear beam dynamics. In 2012, turn-by-turn measurements of large diagonal betatron excitations in LHC Beam 2 were taken at injection energy. Spectral analysis of these measurements shows an anomalous octupolar spectral line at frequency -Qx-2Qy in the horizontal motion. The presence of this spectral line, as well as other lines, was confirmed by measurements taken for LHC Beam 1 and Beam 2 during the commissioning in 2015. We take a close look at the various spectral lines appearing in the LHC transverse motion in order to improve the LHC nonlinear model. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR037 | |
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| THPMR038 | Non-Linear Errors in the Experimental Insertions of the LHC | 3472 |
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| Correction of nonlinear magnetic errors in low-β insertions can be of critical significance for the operation of a collider. This is expected to be of particular relevance to LHC Run II and the HL-LHC upgrade, as well as to future colliders such as the FCC. Current correction strategies for these accelerators have assumed it will be possible to calculate optimized local corrections through the insertions using a magnetic model of the errors. To test this assumption the nonlinear errors in the LHC experimental insertions have been examined via feed-down and amplitude detuning. It will be shown that while in some cases the magnetic measurements provide a sufficient description of the errors, in others large discrepancies exist which will require beam-based correction techniques. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR038 | |
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| THPMR039 | Commissioning of Non-linear Optics in the LHC at Injection Energy | 3476 |
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| Commissioning of the nonlinear optics at injection in the LHC was carried out for the first time in 2015 via beam-based methods. Building upon studies performed during Run I, corrections to the nonlinear chromaticity and detuning with amplitude were obtained. These corrections were observed to reduce beam-loss during measurement of linear optics. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR039 | |
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| THPMR040 | Local Optics Corrections in the HL-LHC IR | 3480 |
| SUPSS046 | use link to see paper's listing under its alternate paper code | |
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| For the high luminosity upgrade of the LHC optics correction in the interaction regions is expected to be challenged by the very low β* and the sizable expected quadrupolar errors in the triplet. This paper addresses the performance and limitations of the segment-by-segment technique to correct quadrupolar and skew quadrupolar errors in the HL-LHC IR via computer simulations. Required improvements to this technique and possible combinations with other correction approaches are also presented including experimental tests in the current LHC IR. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR040 | |
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| THPMR041 | Implementation of High Order Symplectic Integrators with Positive Steps in Tracking Programs | 3484 |
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| The symplectic integrators CSABAν & CSBABν are used in order to calculate single particles dynamics in accelerators and storage rings. These integrators present only positive steps and can be accurate up to the high order. They are compared with already existing splitting methods of MAD-X with respect to their impact on various beam dynamics quantities, for different beam elements. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR041 | |
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| THPMR042 | Design Guidelines for the Injector Complex of the FCC-ee | 3488 |
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| The design of the injector of the FCC-ee, a high-luminosity e+/e− circular collider of 100 km in the Geneva area, is driven by the required particle flux for ring filling or top-up and for a variety of energies, from 45.5 to 175 GeV. In this paper, a set of parameters of the injector complex is presented, fulfilling the collider needs for all running scenarios. In particular, the challenges of the booster ring design are detailed, focusing on issues of optics, layout, low bending fields, injection schemes to the collider for maximizing transfer efficiency and synchrotron radiation handling. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR042 | |
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| THPMR043 | Performance of Transverse Beam Splitting and Extraction at the CERN Proton Synchrotron in the Framework of Multi-turn Extraction | 3492 |
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| Considerable progress has been made in 2015 in the setting up of the multi-turn extraction (MTE) in the CERN Proton Synchrotron (PS). A key ingredient in this novel extraction technique is the beam splitting in transverse phase space. This manipulation is based on adiabatic trapping in stable islands of transverse phase space and requires mastering a number of devices in the PS ring. In addition, an in-depth review of all fast extractions schemes in the PS had been required due to the development and installation of a dummy septum to shield the actual magnetic septum. In this paper, the current performance of the beam splitting and of the extraction including the shadowing effect is presented. Future lines of development will also be discussed. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR043 | |
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| THPMR044 | Short Term Dynamic Aperture with AC Dipoles | 3496 |
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| The dynamic aperture of an accelerator is determined by its non-linear components and errors. Control of the dynamic aperture is important for a good understanding and operation of the accelerator. The AC dipole, installed in the LHC for the diagnostic of linear and non-linear optics, could serve as a tool for the determination of the dynamic aperture. However, since the AC dipole itself modifies the non-linear dynamics, the dynamic aperture with and without AC dipole are expected to differ. This paper will report the results of studies of the effect of the AC dipole on the dynamic aperture. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR044 | |
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| THPMR045 | CLIC Beam Delivery System Rebaselining and Long L* Lattice Optimization | 3500 |
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| This paper summarizes the re-optimization study made on the CLIC Beam Delivery System (BDS) in the framework of the rebaselining for beam collisions at 380 GeV for the initial energy stage. It describes the optimization process applied for the beam parameters as well as for the Final Focus system (FFS) lattice design with respect to the energy upgrade transition to 3 TeV. Both initial and final energy stages were optimized for a short (nominal) and a long L* (6 meters). The long L* option allows the last quadrupole (QD0) to be be located outward of the detector solenoid field influence. FFS optics designs based on the Local chromaticity correction and performance comparisons for both L* options are shown. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR045 | |
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| THPMR046 | Advanced BBA Techniques for the Final Focuses of Future Linear Colliders | 3504 |
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| Tuning the Final-Focus System of future linear colliders is one of the open challenges the linear collider community is undertaking. Future colliders like ILC and CLIC will feature complex lattice design to focus the beams to nanometer level at the Interaction Point. Standard Beam-Based Alignment (BBA) techniques have proven to hardly meet the requirements in terms of acceptable emittance growth, in both machines. A set of new techniques, respectively called: nonlinear Dispersion-Free Steering (DFS), DFS-knobs scan, and hybrid DFS-knobs with beamsize measurements, have been put in place to cope with the challenge. This paper will reveal the key ideas behind the new techniques, and compare their effectiveness w.r.t. the conventional BBA tuning procedures. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR046 | |
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| THPMR047 | Two-beam Tuning in the CLIC BDS | 3508 |
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| Beam tuning in the beam delivery system (BDS) is one of the major challenges for the future linear colliders. In those colliders, due to fast detuning of the final focus optics both beamlines will need to be tuned simultaneously. An initial two-beam tuning study for the Compact Linear Collider (CLIC) BDS had been performed, but was not fully satisfactory. In this paper a more extensive study is presented, as well as several improvements to the tuning algorithm. A comparative study between two competing CLIC final focus systems (FFS), the traditional and the compact FFS, will be discussed. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR047 | |
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| THPMR048 | Analysis of Nonlinear Effects for IDs at the SPS Storage Ring | 3512 |
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Funding: Synchrotron Light Research Institute (Public Organization) To generate intense and high energy synchrotron radiation at the Siam Photon Source (SPS) 1.2 GeV storage ring, two insertion devices (IDs), namely, a 2.2 T hybrid multipole wiggler (MPW) and a 6.5 T superconducting wavelength shifter (SWLS), have been installed and operated since 2013. The angular kicks due to the nonlinear effects generated by the IDs represented by kick maps were used in our analysis. The optics distortion was compared to the ones obtained from calculation using hard-edge model and measurement results. In order to investigate the effects of IDs on the beam dynamics, Frequency Map Analysis (FMA) was employed. The effects of the IDs and their compensation are presented herewith. |
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| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR048 | |
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| THPMR049 | Minimization of Nonlinear Effects of Insertion Devices at SPS Storage Ring | 3515 |
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Funding: Synchrotron Light Research Institute PO. Box 93 Nakhon Ratchasima 30000 Thailand Nonlinear effects of insertion devices were studied for the Siam Photon Source (SPS) storage ring. Despite the fact that shimming technique was used to minimize the nonlinear components of magnetic field integral arising from random errors, the nonlinear dynamics effects still remain. It was found that calculated dynamic field integrals are largest in the 2.2 T Hybrid Multipole Wiggler (MPW). Dynamics effects of insertion devices are attributed to the wiggling trajectory of electron in the region of magnetic field roll-off due to finite pole width. For better and more effective operation of the SPS storage ring, multipole components of the dynamic field integral in the MPW have to be further reduced. |
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| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR049 | |
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| THPMR050 | Studies to Install a Multipole Wiggler by Removing a Chromatic Sextupole in the Diamond Storage Ring | 3518 |
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| Investigations are underway for the possible use of an achromat to install a short multipole wiggler by removing a chromatic sextupole in cell-11 of the storage ring. The effect on emittance and energy spread are found to be small, however the impact on lifetime and injection are very significant if the chromaticity is corrected normally (globally). The MOGA genetic algorithm is used to optimize the lifetime and injection efficiency in this case. We used local mirror chromatic sextupole and other chromatic sextupole family for chromaticity correction in which case the genetic algorithm found solution that restores lifetime and injection efficiency. In this paper the results of MOGA simulations using various schemes for chromaticity correction and test results in presently operational optics will be discussed. | ||
| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR050 | |
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| THPMR052 | Compact, Microtron-Based Gamma Source | 3522 |
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Funding: This work was supported U.S. DOE SBIR Grant DE-SC0013795. The conceptual design of a prototype S-band pulsed, 9.5 MeV compact microtron with type-II injection is described. Estimates of parameters such as beam current and cathode lifetime, and comparisons with X-band and C-band parameters are presented. The electron beam can be extracted at various energies up to 9.5 MeV. Estimated yields of gammas produced at 6.5 MeV operation and estimated yields of gammas and neutrons produced at 9.5 MeV are presented. |
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| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR052 | |
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| THPMR053 | Influence of Magnet Multipole Field Components on Beam Dynamics in the JLEIC Ion Collider Ring | 3525 |
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Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contracts No. DE-AC05-06OR23177 and DE-AC02-06CH11357. Work supported also by the U.S. DOE Contract DE-AC02-76SF00515. To get a luminosity level of a few 1033 cm-2ses−1 at all design points of the Jefferson Lab Electron Ion Collider (JLEIC) project, small β* values in both horizontal and vertical planes are necessary at the Interaction Point (IP) in the ion collider ring. This also means large β in the final focus area, chromaticity correction sections, etc. which sets a constraint on the field quality of magnets in large beta areas, in order to ensure a large enough dynamic aperture (DA). In this context, limiting multipole field components of magnets are surveyed to find a possible compromise between the requirements and what can be realistically achieved by a magnet manufacturer. This paper describes that work. Moreover, non-linear field dedicated correctors are also studied to provide semi-local corrections of specific multipole field components. |
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| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR053 | |
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| THPMR054 | Error Correction for the JLEIC Ion Collider Ring | 3528 |
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Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contracts No. DE-AC05-06OR23177 and DE-AC02-06CH11357. Work supported also by the U.S. DOE Contract DE-AC02-76SF00515. The sensitivity to misalignment, magnet strength error, and BPM noise is investigated in order to specify design tolerances for the ion collider ring of the Jefferson Lab Electron Ion Collider (JLEIC) project. Those errors, including horizontal, vertical, longitudinal displacement, roll error in transverse plane, strength error of main magnets (dipole, quadrupole, and sextupole), BPM noise, and strength jitter of correctors, cause closed orbit distortion, tune change, beta-beat, coupling, chromaticity problem, etc. These problems generally reduce the dynamic aperture at the Interaction Point (IP). According to real commissioning experiences in other machines, closed orbit correction, tune matching, beta-beat correction, decoupling, and chromaticity correction have been done in the study. Finally, we find that the dynamic aperture at the IP is restored. This paper describes that work. |
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| DOI • | reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR054 | |
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