Keyword: sextupole
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MOPAB019 Possible Application of Round-to-Flat Hadron Beam Creation Using 3rd Order Coupling Resonances for the Electron-Ion Collider resonance, emittance, coupling, electron 99
 
  • J. Kallestrup
    PSI, Villigen PSI, Switzerland
  • X. Gu
    BNL, Upton, New York, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
An Electron-Ion Collider (EIC) is planned to be built in Brookhaven National Laboratory with the contribution from Jefferson National Laboratory. To have a high luminosity, both the EIC ion bunch and the EIC electron bunch are designed to be flat during their collision. The existing injector source provides a round beam of width 2.5 um rad transverse emittances. In this paper we investigate the option of dynamically crossing the 2Qx-Qy coupling resonance in order to create a flat-beam with emittance ratio Ex/Ey of up to 4. Furthermore, we explore the possibility of using a pulsed- or AC skew sextupole magnets to achieve a similar effect. Using one of these methods for flat beam creation will help lower the ion beam cooling time. 		 
poster icon Poster MOPAB019 [0.323 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB019  
About • paper received ※ 19 May 2021       paper accepted ※ 02 June 2021       issue date ※ 24 August 2021  
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MOPAB020 Improvements to the SLS Booster Synchrotron Performance Towards SLS 2.0 booster, emittance, coupling, injection 103
 
  • J. Kallestrup, M. Aiba
    PSI, Villigen PSI, Switzerland
  
  The Swiss Light Source (SLS) storage ring will undergo a major upgrade to a multi-bend achromat lattice. The existing injector complex will be reused with few modifications. However, the SLS booster synchrotron has not been studied since the initial commissioning in years 2000-2001. We plan to apply an emittance exchange in the booster to lower the horizontal emittance, which is a critial parameter for the injection. Here, we present improvements to the SLS booster as a preparation for SLS 2.0 upgrade project. The vertical beam size is decreased by 50\% by the use of vertical orbit correctors without beam position monitors, leading also to suppression of vertical dispersion and a factor 10 reduction of the transverse coupling coefficient. The emittance exchange reflected these improvements in the horizontal emittance, achieving a factor of 9-10 reduction. Lastly, a fast head-tail instability limiting the injection rate into the storage ring is discovered and subsequently suppressed by correcting the chromaticities.  
poster icon Poster MOPAB020 [0.380 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB020  
About • paper received ※ 19 May 2021       paper accepted ※ 01 June 2021       issue date ※ 30 August 2021  
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MOPAB035 Modified Lattice of the Compact Storage Ring in the cSTART Project at Karlsruhe Institute of Technology quadrupole, lattice, octupole, storage-ring 159
 
  • A.I. Papash, E. Bründermann, B. Härer, A.-S. Müller, R. Ruprecht, J. Schäfer, M. Schuh
    KIT, Karlsruhe, Germany
  
  A very large acceptance compact storage ring (VLA-cSR) is under design at the Institute for Beam Physics and Technology (IBPT) of the Karlsruhe Institute of Technology (KIT, Germany). The combination of a compact storage ring and a laser wakefield accelerator (LWFA) might be the basis for future compact light sources and advancing user facilities. Meanwhile, the post-LWFA beam should be adapted for storage and accumulation in a dedicated storage ring. Modified geometry and lattice of a VLA-cSR operating at 50 MeV energy range have been studied in detailed simulations. The main features of a new model are described here. The new design, based on 45° bending magnets, is suitable to store the post-LWFA beam with a wide momentum spread (1% to 2%) as well as ultra-short electron bunches in the fs range from the Ferninfrarot Linac- Und Test- Experiment (FLUTE). The DBA-FDF lattice with relaxed settings, split elements, and higher-order optics of tolerable strength allows improving the dynamic aperture to an acceptable level. This contribution discusses the lattice features in detail and different possible operation schemes of a VLA-cSR.  
poster icon Poster MOPAB035 [1.405 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB035  
About • paper received ※ 10 May 2021       paper accepted ※ 27 May 2021       issue date ※ 24 August 2021  
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MOPAB038 Robustness Studies and First Commissioning Simulations for the SOLEIL Upgrade Lattice lattice, alignment, MMI, simulation 171
 
  • D. Amorim, A. Loulergue, L.S. Nadolski, R. Nagaoka
    SOLEIL, Gif-sur-Yvette, France
  
  Diffraction limited light sources will use very strong focusing elements to achieve their emittance goal. The beam will therefore be more sensitive to magnet field and alignment errors. Impact of errors on the lattice proposed for the SOLEIL upgrade was studied with the Accelerator Toolbox (AT) code. The performance achieved with the imperfect lattice will be presented. In particular the effect of girders misalignment was also accounted for. As the lattice uses a large number of permanent magnets for the beam bending as well as the focusing, challenges arise in terms of beam correction. The correctors and BPMs location and number will be investigated to maximize their efficiency, and corrector magnet strength required to obtain a closed orbit will be studied. The commissioning strategy, and in particular the method used to achieve the first turns and a stored beam in the machine will also be exposed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB038  
About • paper received ※ 19 May 2021       paper accepted ※ 31 May 2021       issue date ※ 16 August 2021  
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MOPAB039 Amplitude-Dependent Shift of Betatron Tunes and Its Relation to Long-Term Circumference Variations at NSLS-II lattice, simulation, closed-orbit, wiggler 175
 
  • L.H. Yu, G. Bassi, Y. Hidaka, B. Podobedov, V.V. Smaluk, G.M. Wang, X. Yang
    BNL, Upton, New York, USA
  
  The comparison of amplitude tune dependence measured for NSLSII lattices with models indicated the large change of amplitude tune dependence over time apparently can not be solely explained by magnets variation or beta function changes, but it seems can be explained by energy changes. On the other hand, the energy change required by fitting with the amplitude tune dependence change is too large to be explained by the RF frequency change and the change of the sum of correctors in the period of the measurements. To explain this apparent contradiction, our analysis shows the long term storage ring circumference change can explain the apparent energy change. Our data indeed shows a seasonal change of the amplitude tune dependence over long term observation. This clearly also indicated a relation to long term closed orbit drift. Hence the current work indicates a new strategy to study how to use amplitude tune dependence as a guideline to analyze long term lattice parameter shifts and closed orbit drift, and improve the orbit and machine performance stability.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB039  
About • paper received ※ 09 May 2021       paper accepted ※ 26 May 2021       issue date ※ 26 August 2021  
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MOPAB048 Robust Design and Control of the Nonlinear Dynamics for BESSY-III lattice, controls, optics, synchrotron 209
 
  • J. Bengtsson, M. Abo-Bakr, P. Goslawski, A. Jankowiak, B.C. Kuske
    HZB, Berlin, Germany
  
  The design philosophy for a robust prototype lattice design for BESSY III, i.e., that is insensitive to small parameter changes, e.g. engineering tolerances - based on a higher-order-achromat, a la: SLS, NSLS-II, MAX IV, and SLS 2 - is outlined & presented. As usual, a well optimized design requires a clear understanding of the end-user requirements and close collaboration between the linear optics designer and nonlinear dynamics specialist for a systems approach.  
poster icon Poster MOPAB048 [1.202 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB048  
About • paper received ※ 17 May 2021       paper accepted ※ 24 May 2021       issue date ※ 27 August 2021  
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MOPAB065 Optimization of the Lattice Replacement Options for the Next Generation Australian Synchrotron lattice, emittance, synchrotron, storage-ring 269
 
  • R. Auchettl, R.T. Dowd, Y.E. Tan
    AS - ANSTO, Clayton, Australia
  
  The design of a next generation Australian Synchrotron replacement lattice is a multi-objective and multi-constrained problem. Our group was tasked to produce a low emittance design while re-using the existing tunnel infrastructure and injector system. Our objectives coupled with the set infrastructure constraints are not straightforward to achieve with manual design. Several variables act at cross-purposes to one-another, leading to a conflicting trade-off between objectives. Recently we have investigated replacement options for the Australian Synchrotron containing longitudinal gradient and reverse bends in the form of a 4BA (4-bend achromat) lattice. In this work, optimise the lattice design for a potential fourth generation Australian Synchrotron facility. We outline the baseline 4BA solution to the lowest emittance lattice that can reuse the existing tunnels and injector system.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB065  
About • paper received ※ 19 May 2021       paper accepted ※ 28 May 2021       issue date ※ 19 August 2021  
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MOPAB074 Preliminary Study of Design Method for Hybrid MBA Lattice lattice, resonance, linear-dynamics, emittance 297
 
  • J.J. Tan, Z.H. Bai, Z.L. Ren, J.H. Xu
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
  • Q. Zhang
    INEST, Hefei, People’s Republic of China
  
  Nonlinear optimization of hybrid multi-bend-achromat (HMBA) lattice is a difficult task due to its quite limited variables of multipole magnets. As a result, it is necessary to consider nonlinear potential of the lattice in its linear design. Nonlinear dynamics can be estimated by nonlinear driving terms and detuning terms. In this paper, we propose a design method for HMBA lattice. In this method, objective functions include emittance and two indicators of nonlinear dynamics, which consist of nonlinear driving terms and detuning terms. As an example, an HMBA lattice for a 2.2 GeV storage ring with circumference of 460.8 m was designed to demonstrate the method.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB074  
About • paper received ※ 19 May 2021       paper accepted ※ 21 May 2021       issue date ※ 21 August 2021  
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MOPAB081 Feasibility Study of Using Multipole Injection Kicker (MIK) and Sextupole for TPS Injection injection, storage-ring, kicker, GUI 312
 
  • C.-S. Fann, C.K. Chan, C.-C. Chang, H.-P. Chang, Y.-S. Cheng, M.-S. Chiu, Y.L. Chu, K.T. Hsu, S.Y. Hsu, K.H. Hu, J.C. Huang, C.-S. Hwang, S.H. Lee, K.-K. Lin, C.Y. Wu, C.S. Yang
    NSRRC, Hsinchu, Taiwan
  • S.-Y. Lee
    Indiana University, Bloomington, Indiana, USA
  
  Feasibility of applying MIK/sextupole injection at TPS is evaluated in this study. This study adopts layout similar to MAX IV injection scheme and their collaboration project with SOLEIL for MIK. Although the light source service fulfills present user needs, yet the increasing demands for a transparent injection is inevitable in the foreseeable future. Notice that this preliminary study is constrained under routine user operation, the optional pinger ceramic chamber, located between existing injection kicker-3 and kicker-4, is chosen for the purpose. Kick strength requirement of the MIK is estimated with minor trajectory adjustment upstream at the booster to storage ring transfer line. Since the realization of MIK fabrication takes time, therefore a fast-built sextupole is prepared to examine the proposed injection scheme beforehand. The test result will be described in this report.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB081  
About • paper received ※ 17 May 2021       paper accepted ※ 20 May 2021       issue date ※ 21 August 2021  
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MOPAB103 Study of Transverse Oscillation Coupling and Possibility of Its Minimization in SKIF (Novosibirsk) coupling, quadrupole, emittance, storage-ring 383
 
  • D. Leshenok
    BINP, Novosibirsk, Russia
  • G.N. Baranov, E.B. Levichev, S.A. Nikitin
    BINP SB RAS, Novosibirsk, Russia
  
  The vertical emittance and, in general, the vertical beam size and angular divergence are of paramount importance in the SKIF (Russian acronym for Siberian Circular Photon Source) project developed in Novosibirsk. Therefore, a detailed simulation of the corresponding influence of possible errors in the storage ring was carried out with cross-validation by different methods. Variants of cross-coupling correction are proposed and modeled to obtain a vertical emittance of the order of one picometer simultaneously with minimizing vertical dispersion.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB103  
About • paper received ※ 18 May 2021       paper accepted ※ 17 August 2021       issue date ※ 19 August 2021  
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MOPAB106 Enhancing the MOGA Optimization Process at ALS-U with Machine Learning lattice, dynamic-aperture, emittance, storage-ring 387
 
  • Y. Lu, M.P. Ehrlichman, T. Hellert, S.C. Leemann, H. Nishimura, C. Sun, M. Venturini
    LBNL, Berkeley, California, USA
  
  Funding: This research is funded by the US Department of Energy(BES & ASCR Programs), and supported by the Director of the Office of Science of the US Department of Energy under Contract No. DEAC02-05CH11231.
The bare lattice optimization for the linear and nonlinear ALS-U storage ring lattice, even without reverse bending, comprises 11 degrees of freedom (DoF) and is therefore a very complex and highly time-consuming process. This design process relies heavily on multi-objective genetic algorithms (MOGA), usually requiring many months of experienced scientists’ time. The main problem lies in having to evaluate numbers of candidate lattices due to the stochastic process of MOGA. Although almost all of these candidates are eventually rejected, they nevertheless require extensive particle tracking to arrive at a Pareto front. We therefore propose a novel Machine Learning (ML) pipeline that nonlinear tracking is replaced by two well-trained neural networks (NNs) to predict dynamic aperture (DA) and momentum aperture (MA) for any lattice candidate. Initial training of these models takes only several minutes on conventional CPUs while predictions are then rendered near instantaneously. We present this novel method and demonstrate the resulting orders of magnitude speedup of the ML-enhanced MOGA process on a 2-DoF problem as well as first results on a more complex 11-DoF problem. 		 
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DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB106  
About • paper received ※ 19 May 2021       paper accepted ※ 01 June 2021       issue date ※ 18 August 2021  
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MOPAB109 A Lattice for PETRA IV Based on the Combination of Different Arc Cell Designs lattice, undulator, emittance, resonance 399
 
  • J. Keil, I.V. Agapov, R. Brinkmann
    DESY, Hamburg, Germany
  
  The 6 GeV synchrotron light source PETRA III at DESY is in user operation since 2009. In 2016 investigations of upgrading PETRA III into a diffraction limited storage ring at 10 keV have been started. The ambitious goal is to achieve an emittance in the range of 10-30 pm*rad. For the conceptual design report (CDR) of PETRA IV a lattice based on hybrid multi-bend achromats (HMBA) has been chosen. It consists of eight arcs connected by eight long straight sections whereas each arc consists of eight HMBA cells. While this lattice variant has an advantage in terms of simplicity of magnet and girder design it is challenging in regards of multipole strengths and beam dynamic properties. However, only a part of all eight arcs will be used for undulator beamlines. This offers the possibility to choose a more relaxed optics design in the arcs without undulators while preserving the ultra-low emittance. In addition, the use of reverse bends in the undulator cells allows smaller beta functions at the undulators for an increased brilliance. The design and the beam dynamic properties of this combi lattice are discussed in this paper and compared to the lattice based on HMBA cells.  
poster icon Poster MOPAB109 [1.338 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB109  
About • paper received ※ 18 May 2021       paper accepted ※ 28 May 2021       issue date ※ 30 August 2021  
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MOPAB110 An Electron Synchrotron Lattice Based on Theoretic Minimal Emittance Cell emittance, lattice, extraction, synchrotron 403
 
  • H.C. Chao
    DESY, Hamburg, Germany
  
  A design of an electron synchrotron featuring the theoretic minimal emittance (TME) cells is presented. It has 32 superperiods and the circumference is around 300 m. It offers versatile functions with the equilibrium emittance less than 10 nm-rad at 6 GeV. The beam energy can go up to 7 GeV. Locations with proper phase advances are found to form effective vertical orbit bumps, which can be used for the injections and extraction. A tune scan study shows the sweet spot for the working point. Some discussions of other usages and studies of synchro-betatron coupling effects are also included in this article.  
poster icon Poster MOPAB110 [0.777 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB110  
About • paper received ※ 11 May 2021       paper accepted ※ 28 May 2021       issue date ※ 30 August 2021  
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MOPAB183 A Framework for Dynamic Aperture Studies for Colliding Beams in the High-Luminosity Large Hadron Collider luminosity, simulation, operation, beam-beam-effects 620
 
  • S. Kostoglou, H. Bartosik, Y. Papaphilippou, G. Sterbini
    CERN, Geneva, Switzerland
  
  During the last physics run of the Large Hadron Collider (LHC), Dynamic Aperture (DA) studies have been successfully employed to optimize the accelerator’s performance by guiding the selection of the beam and machine parameters. In this paper, we present a framework for single-particle tracking simulations aiming to refine the envisaged operational scenario of the future LHC upgrade, the High-Luminosity LHC (HL-LHC), including strong non-linear fields such as beam-beam interactions. The impact of several parameters and beam processes during the cycle is initially illustrated with frequency maps and then quantified with DA studies.  
poster icon Poster MOPAB183 [2.789 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB183  
About • paper received ※ 17 May 2021       paper accepted ※ 06 July 2021       issue date ※ 23 August 2021  
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MOPAB220 Towards Deterministic Design of MBA-Lattices dipole, lattice, emittance, quadrupole 722
 
  • B.C. Kuske
    HZB, Berlin, Germany
  
  Funding: Work supported by the German Bundesministerium für Bildung und Forschung, Land Berlin and grants of the Helmholtz Association
Since the pioneering work of MAX IV *, multi-bend achromat (MBA) lattices have become the standard in lattice design for 4th generation lights sources as well as upgrades of 3rd generation storage rings. The distribution of the bending angle to many weak dipoles enables to reach unprecedented low emittance and highest brightness. In their most basic form, MBA-lattices consist of a repetitive unit cell and two identical matching cells on either end of the achromatic arc. The simplicity of both cells allows for a unique determination of the linear lattice parameters in dependence on boundary conditions defined by the design goals. Those might be the emittance, momentum compaction factor, chromaticity, as well as phase advances with respect to achieving higher-order achromatic structures. A scan of optional lattice prototypes is quickly obtained. We demonstrate this concept and apply it in the design of the first candidates for the lattice of BESSY III, a green-field 4th generation storage ring being currently planned at HZB, Berlin, Germany.
* https://www.maxiv.lu.se/accelerators-beamlines/accelerators/accelerator-documentation/max-iv-ddr/ 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB220  
About • paper received ※ 17 May 2021       paper accepted ※ 23 July 2021       issue date ※ 26 August 2021  
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MOPAB225 A HMBA Lattice Design Study for the 4 GeV Light Source lattice, storage-ring, emittance, dipole 734
 
  • S.W. Jang, E.-S. Kim
    KUS, Sejong, Republic of Korea
  
  The 4th generation storage ring (4GSR) project will start from 2022 in South Korea. We proposed HMBA (Hybrid Multi-Bend Achromatic) lattice for 4GSR with super-bend at the center of the lattice. The 4GSR lattice is designed to combined HMBA lattice with a 4 GeV, 53 pm-rad emittance and 843m. The storage ring including 32 long with 5.65m, 16 short straight with 1.3m sections for IDs and 16 super-bend sections for more different type of beam line experiments. A calculated dynamic aperture is more larger than 15mm in both direction and the beam life time is expected to 4.7 hour. In this paper, we will describe the study results of the HMBA lattice design with a 4GeV light source.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB225  
About • paper received ※ 20 May 2021       paper accepted ※ 24 May 2021       issue date ※ 30 August 2021  
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MOPAB229 Compensations of Third-Order Resonances in J-PARC MR resonance, operation, optics, survey 744
 
  • T.Y. Yasui, S. Igarashi, T. Koseki, Y. Kurimoto, Y. Morita, K. Ohmi, Y. Sato, T. Shimogawa
    KEK, Tokai, Ibaraki, Japan
  
  The main ring synchrotron (MR) of the Japan Proton Accelerator Research Complex (J-PARC) provides high-power proton beams for the neutrino and hadron experiments. In the fast extraction (FX) operation, the beams are injected with the energy of 3 GeV and the intensity of 3.3 × 1013 protons per bunch, and accelerated to 30 GeV. Most of the beam losses are observed in the low-energy period, because the space charge tune spread is large, and crosses various kinds of resonances. In this study, the compensations of the third-order resonances are performed. The present operation tune is (νx, νy) = (21.35, 21.43) in FX operation. The nearest third-order structure resonance is νx-2νy=-21. It was clearly compensated by optimizing the phase advances in the arc sections. The compensation was confirmed by the aperture survey simulations and demonstrated by the three different experiments. The third-order nonstructure resonances near the operation tune are 3νx=64 and νx+2νy=64. They are simultaneously compensated by introducing four trim coils of the sextupole magnets. The beam loss was successfully reduced by adopting the compensations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB229  
About • paper received ※ 20 May 2021       paper accepted ※ 02 June 2021       issue date ※ 29 August 2021  
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MOPAB230 The Optics Design for the Final Focus System of CLIC 380 GeV optics, luminosity, quadrupole, target 748
 
  • A. Pastushenko, R. Tomás García
    CERN, Geneva, Switzerland
  • A. Faus-Golfe
    Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
  
  The first stage of the Compact Linear Collider (CLIC) is planned to be at the center-of-mass energy of 380 GeV. The final focus system (FFS) was re-optimized for this energy and for L* of 6 m (distance between the Interaction Point (IP) and the last quadrupole, QD0). Furthermore, the FFS optics was optimized for the vertical beta-function of 70 microns to approach the Hourglass effect limit. This paper reports the exploration of shortening the Final Doublet (FD) within the FFS to reduce the chromaticity. In addition, an alternative optics design is investigated with a different dispersion profile along the FFS, which outperforms the previous optics with the same β*, increasing luminosity by 5 %.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB230  
About • paper received ※ 19 May 2021       paper accepted ※ 14 June 2021       issue date ※ 11 August 2021  
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MOPAB254 Measurement of Horizontal Beam Size Using Sextupole Magnets quadrupole, storage-ring, positron, dipole 802
 
  • J.A. Crittenden, K.E. Deitrick, H.X. Duan, G.H. Hoffstaetter, V. Khachatryan, D. Sagan
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  
  Funding: This work is supported by National Science Foundation award number DMR-1829070.
The quadratic dependence of sextupole fields on position results in a beam-size-dependent kick on a beam traversing a sextupole magnet. A change in sextupole strength changes the closed orbit and the tune of the beam in a storage ring. Measuring both therefore allows conclusions about the beam size in the sextupole. Here we derive the pertinent formula and discuss the applicability to storage rings. In particular we investigate the measurement accuracy that can be achieved at the Cornell High Energy Synchrotron Source. The Cornell Electron-positron Storage Ring underwent a major upgrade in 2018 with the goal of reducing the emittance by a factor of four. A variety of beam size measurement methods have been developed to monitor the positron beam size, including visible synchrotron light and interferometry. We investigate the sensitivity of the sextupole method and compare to other measurement techniques. The design horizontal emittance of the 6-GeV positron beam is about 30 nm-rad with typical beam sizes of about 1 mm, setting the scale for the required accuracy in the beam-size measurement. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB254  
About • paper received ※ 19 May 2021       paper accepted ※ 22 June 2021       issue date ※ 01 September 2021  
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MOPAB261 NSLS-II Storage Ring Lattice Analysis using Response Matrices lattice, quadrupole, alignment, storage-ring 829
 
  • J. Choi
    BNL, Upton, New York, USA
  
  Funding: Work supported by the U.S. Department of Energy (DOE) under contract No. DE-SC0012704.
Affected from various sources, the NSLS-II storage ring lattice is slightly changing operation to operation and, for the operational performance, we are continually optimizing the lattice and maintaining the response matrices for the feedback and lattice analysis. Because not all sources are identified, we are investing efforts to identify as many as possible. As one of such efforts, we also study the measured response matrices. In this paper, we present the results of lattice studies using a pair of recently measured response matrices. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB261  
About • paper received ※ 20 May 2021       paper accepted ※ 02 June 2021       issue date ※ 19 August 2021  
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MOPAB262 First Thoughts on Lattices for a possible Metrology Light Source 2 lattice, emittance, dipole, radiation 833
 
  • M. Arlandoo, M. Abo-Bakr, P. Goslawski, J. Li
    HZB, Berlin, Germany
  
  The Physikalisch-Technische Bundesanstalt (PTB), in cooperation with the Helmholtz-Zentrum Berlin (HZB), operates the Metrology Light Source (MLS), which is a low-energy electron storage ring. The MLS can be operated in a low-alpha mode to produce coherent synchroton ration in the far-IR and THz spectral range. In the scope of the Conceptual Design process for a BESSY II successor, the PTB also requested for an MLS successor to cover their increasing demands on synchrotron radiation. A combination of two different machines, one optimized for low emittance (BESSY III) and one for flexible timing capabilities (MLS II), would provide best radiation capabilities for our user community. In this paper, we discuss the demands on the MLS II and propose first lattice candidates which may meet the needs of the PTB and HZB. Currently, we focus on linear lattices for standard user mode with first steps towards nonlinear optimization.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB262  
About • paper received ※ 18 May 2021       paper accepted ※ 02 June 2021       issue date ※ 17 August 2021  
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TUPAB005 Emittance Estimates for the Future Circular Collider emittance, quadrupole, alignment, simulation 1338
 
  • L. van Riesen-Haupt, T.K. Charles, R. Tomás García, F. Zimmermann
    CERN, Meyrin, Switzerland
  • T.K. Charles
    The University of Liverpool, Liverpool, United Kingdom
  
  The alignment strategy of the FCC-ee has a large impact on its luminosity. Larger alignment tolerances result in increased coupling and a subsequently higher vertical emittance. At the same time, tighter alignment tolerances around the 100 km ring are a major cost driver. This paper applies analytical emittance estimate methods to the FCC-ee and compares their predictions to data from simulations with different alignment tolerances. These methods can be used to help understand the impact of misalignments of certain magnet groups and to come up with an efficient alignment strategy.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB005  
About • paper received ※ 16 May 2021       paper accepted ※ 14 June 2021       issue date ※ 26 August 2021  
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TUPAB058 Online Optimizations of Several Observable Parameters at the Advanced Photon Source injection, storage-ring, kicker, photon 1492
 
  • Y.P. Sun
    ANL, Lemont, Illinois, USA
  
  Funding: The work is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
Online optimizations are known to be powerful tools which may quickly and efficiently improve the particle accelerator key performance parameters in a model-independent way. In this paper, it is presented on the online optimizations of several observable parameters at the Advanced Photon Source storage ring. These observable parameters include the beam lifetime, injection efficiency and topup efficiency, transverse beam sizes, and turn by turn beam position monitors. It is demonstrated that the particle accelerator performance may be greatly enhanced in a relatively short time frame, by optimizing these observable parameters. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB058  
About • paper received ※ 20 May 2021       paper accepted ※ 24 June 2021       issue date ※ 16 August 2021  
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TUPAB213 Important Drift Space Contributions to Non-Linear Beam Dynamics resonance, lattice, operation, storage-ring 1914
 
  • J. Frank, M. Arlandoo, P. Goslawski, J. Li, T. Mertens, M. Ries
    HZB, Berlin, Germany
  
  This paper presents an in-depth analysis of the non-linear contributions of drift spaces in beam dynamics for the creation of Transverse Resonance Island Buckets (TRIBs). TRIBs have been successfully generated in BESSY II and MLS at the Helmholtz-Zentrum Berlin für Materialien und Energie GmbH (HZB). They offer the possibility of generating a second stable orbit and, by populating the orbit with a different electron bunch pattern, allow to effectively have two distinct radiation sources in the same machine individually tailored to different user needs. We demonstrate the generation of TRIBs by order of non-linearity on simple lattice configurations by only treating the drift space as the non-linear element. Moreover, we also insert other non-linear magnets to show how they modify the already generated TRIBs from the drift spaces. We conclude by giving a qualitative analysis of the occurring effects, which provides a guideline as to when the linear approximation is insufficient and the non-linear contribution has to be taken into account.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB213  
About • paper received ※ 12 May 2021       paper accepted ※ 31 August 2021       issue date ※ 29 August 2021  
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TUPAB223 Design of Double- and Multi-Bend Achromat Lattices with Large Dynamic Aperture and Approximate Invariants lattice, storage-ring, resonance, betatron 1945
 
  • Y. Li, R.S. Rainer, V.V. Smaluk
    BNL, Upton, New York, USA
  • K. Hwang, C.E. Mitchell, R.D. Ryne
    LBNL, Berkeley, California, USA
  
  Funding: Funded by U.S. Department of Energy (DOE) under Contract No. DE-SC0012704 (BNL) and DE-AC02-05CH11231 (LBNL), U.S. DOE Early Career Research Program under the Office of High Energy Physics.
A numerical method to design nonlinear double- and multi-bend achromat (DBA and MBA) lattices with approximate invariants of motion is described. The search for such nonlinear lattices is motivated by Fermilab’s Integrable Optics Test Accelerator (IOTA), whose design is based on an integrable Hamiltonian system with two invariants of motion. While it may not be possible to design an achromatic lattice for a dedicated synchrotron light source storage ring with one or more exact invariants of motion, it is possible to tune the sextupoles and octupoles in existing DBA and MBA lattices to produce approximate invariants. In our procedure, the lattice is tuned while minimizing the turn-by-turn fluctuations of the Courant-Snyder actions Jx and Jy at several distinct amplitudes, while simultaneously minimizing diffusion of the on-energy betatron tunes. The resulting lattices share some important features with integrable ones, such as a large dynamic aperture, trajectories confined to invariant tori, robustness to resonances and errors, and a large amplitude-dependent tune-spread. 		 
poster icon Poster TUPAB223 [2.392 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB223  
About • paper received ※ 10 May 2021       paper accepted ※ 15 June 2021       issue date ※ 20 August 2021  
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TUPAB227 Simultaneous Compensation of Phase and Amplitude Dependent Geometrical Resonances Using Octupoles octupole, lattice, emittance, resonance 1960
 
  • F. Plassard, Y. Hidaka, Y. Li, T.V. Shaftan, V.V. Smaluk, G.M. Wang
    BNL, Upton, New York, USA
  
  As the new generation of light sources are pushing toward diffraction limited storage rings with ultra-low emittance beams, nonlinear beam dynamics become increasingly difficult to control. It is a common practice for modern designs to use a sextupole scheme that allows simultaneous correction of natural chromaticity and energy independent, or geometrical, sextupolar resonances. However, the remaining higher order terms arising from the cross talks of the sextupole families set a strong limitation on the achievable dynamic aperture. This paper presents a simulation-based recipe to use octupoles together with this sextupole scheme to provide simultaneous self-compensation of linear amplitude dependent tune shift together with phase-dependent octupolar and higher order geometrical resonant driving terms. The correction method was built based on observations made on a simple FODO model, then applied to a realistic low emittance lattice, designed in the framework of the upgrade of the National Synchrotron Light Source II (NSLS-II).  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB227  
About • paper received ※ 19 May 2021       paper accepted ※ 23 June 2021       issue date ※ 14 August 2021  
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TUPAB235 Dynamic Aperture Optimization in the EIC Electron Storage Ring with Two Interaction Points electron, lattice, collider, dynamic-aperture 1984
 
  • D. Marx, Y. Li, C. Montag, S. Tepikian, F.J. Willeke
    BNL, Upton, New York, USA
  • Y. Cai, Y.M. Nosochkov
    SLAC, Menlo Park, California, USA
  • G.H. Hoffstaetter, J.E. Unger
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 and by SLAC under Contract No. DE-AC02-76SF00515 with the U.S. Department of Energy.
In the Electron-Ion Collider (EIC), which is currently being designed for construction at Brookhaven National Laboratory, electrons from the electron storage ring will collide with hadrons, producing luminosities up to 1034 cm-2 s-1. The baseline design includes only one interaction point (IP), and optics have been found with a suitable dynamic aperture in each dimension. However, the EIC project asks for the option of a second IP. The strong focusing required at the IPs creates a very large natural chromaticity (about -125 in the vertical plane for the ring). Compensating this linear chromaticity while simultaneously controlling the nonlinear chromaticity to high order to achieve a sufficient momentum acceptance of 1% (10 σ) at 18 GeV is a considerable challenge. A scheme to compensate higher-order chromatic effects from 2 IPs by setting the phase advance between them does not, by itself, provide the required momentum acceptance for the EIC Electron Storage Ring. A thorough design of the nonlinear optics is underway to increase the momentum acceptance using multiple sextupole families, and the latest results are presented here. 		 
poster icon Poster TUPAB235 [3.426 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB235  
About • paper received ※ 19 May 2021       paper accepted ※ 19 July 2021       issue date ※ 20 August 2021  
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TUPAB238 Algorithm to Analyze Complex Magnetic Structures Using a Tube Approach quadrupole, multipole, HOM, octupole 1995
 
  • B. Riemann, M. Aiba
    PSI, Villigen PSI, Switzerland
  
  Modern synchrotron light sources often require sophisticated multipole field distributions that need to be realized by complex magnet structures. To pre-validate these magnet structures via simulations, the extraction procedure needs to output standard multipoles as well as fringe effects. The approach presented in this manuscript uses a volumetric grid map of the magnetic flux density as input. After computation of the reference trajectory (leapfrog integration), a large linear system is solved to compute transverse polynomial coefficients of the magnetic scalar potential in a series of interconnected thin cylinders (linear basis functions) along with that reference. The import of these coefficients into a lattice simulation is discussed using a modification of the tracking code Tracy. The shown approach is routinely used to check models of SLS 2.0 magnets for their properties.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB238  
About • paper received ※ 18 May 2021       paper accepted ※ 17 June 2021       issue date ※ 31 August 2021  
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TUPAB311 Nonlinear Correctors Tuning for the Collector Ring Isochronous Mode betatron, optics, controls, proton 2218
 
  • M.A. Lyalin, I. Koop, D.B. Shwartz
    BINP SB RAS, Novosibirsk, Russia
  • I. Koop, M.A. Lyalin, D.B. Shwartz
    NSU, Novosibirsk, Russia
  
  One of the operating modes for the Collector Ring (CR) under construction in Darmstadt is the isochronous mode, in which the captured ions circulate with an equal period regardless of their momentum. The measurement of the orbital period T by the time-of-flight sensors makes it possible to precisely determine the mass to the charge ratio of the ion under study. For this, the change of the circulation period dT should not exceed 1·10-6 for dT/T in the entire momentum acceptance of the 0.62%. Modeling in the Strategic Accelerator Design code showed that without nonlinear effects compensation, the orbital period variation is 1·10-5. In this work, the parameters of nonlinear correctors, which are sextupoles and octupoles in CR, are determined, necessary for the isochronous mode implementation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB311  
About • paper received ※ 29 May 2021       paper accepted ※ 16 June 2021       issue date ※ 14 August 2021  
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TUPAB369 A Fast Non-Linear Model for the EBS Combined Sextupole-Corrector Magnets SRF, dipole, multipole, quadrupole 2381
 
  • G. Le Bec
    ESRF, Grenoble, France
  
  Corrector are often integrated in higher order accelerator magnets. In the new ESRF-EBS storage ring, the sextupoles include additional windings allowing for dipole and skew quadrupole corrections. The accurate modelization of such magnets is not as trivial as it may appear, due to their non-linearities and to the crosstalk between their channels. Changing any corrector current induce non-linear errors in the other corrector channels and in the main sextupole strength, making difficult the trimming of the magnets. A model based on a non-linear excitation curve and quadratic contributions from corrector currents was developed. This model is very fast and was included in the accelerator control system to compute the corrector currents in real-time. It was tested against 3D magnetic simulations and magnetic measurements and compared to a simpler matrix-based model.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB369  
About • paper received ※ 17 May 2021       paper accepted ※ 31 August 2021       issue date ※ 22 August 2021  
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TUPAB379 Superconducting Magnets for Super-FRS: Production and Testing Status dipole, quadrupole, superconductivity, superconducting-magnet 2405
 
  • H. Müller, A. Chiuchiolo, E.J. Cho, G. Golluccio, F. Greiner, P. Kosek, M. Michels, C. Roux, K. Sugita, V.V. Velonas, M. Winkler
    GSI, Darmstadt, Germany
  • H. Allain, A. Madur
    CEA-IRFU, Gif-sur-Yvette, France
  • A. Borceto, G. Drago, G. Valesi
    ASG, Genova, Italy
  • M. Garcia Escudero, M. Lopez, J. Lucas
    Elytt Energy, Madrid, Spain
  • G. Riddone, S. Russenschuck
    CERN, Geneva, Switzerland
  
  The Super FRS is a two-stage in flight separator to be built next to the site of GSI, Darmstadt, Germany as part of FAIR (Facility for Anti-proton and Ion Research). Its three branches allow to carry out a wide variety of experiments. Due to the large acceptance needed, the magnets of the Super-FRS require a large aperture and therefore only a superconducting solution is feasible. A superferric design was chosen in which the magnetic field is shaped by an iron yoke. For the dipole magnets only the superconducting coils are in a cryostat. These magnets are manufactured by Elytt Energy (Spain). The multiplets, assemblies of quadrupoles and higher order multipole magnets, are completely immersed in a liquid Helium bath. They are being built at ASG (Italy). The first of two first of series multiplets, a short assembly containing 2 magnets, was tested at a dedicated test facility at CERN (Switzerland). The 2nd FoS multiplet, containing 9 magnets, and the FoS dipole will be tested soon. Series production of the multiplets has started. In this paper we will present the status of production and testing of the different superconducting magnets for Super-FRS.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB379  
About • paper received ※ 19 May 2021       paper accepted ※ 31 August 2021       issue date ※ 16 August 2021  
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WEPAB011 Update on the Low Emittance Tuning of the e+/e- Future Circular Collider alignment, emittance, quadrupole, lattice 2601
 
  • T.K. Charles
    The University of Liverpool, Liverpool, United Kingdom
  • B.J. Holzer, F. Zimmermann
    CERN, Geneva, Switzerland
  • K. Oide
    KEK, Ibaraki, Japan
  
  The FCC-ee project studies the design of a future 100 km e+/e circular collider for precision studies and rare decay observations in the range of 90 to 350 GeV center of mass energy with luminosities in the order of 1035 cm-2 s−1. To achieve ultra-low vertical emittance a highly effective emittance tuning scheme is required. In this paper, we describe a comprehensive correction strategy used for the low emittance tuning. The strategy includes Dispersion Free Steering, linear coupling compensation based on Resonant Driving Terms and beta beat correction utilising response matrices.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB011  
About • paper received ※ 18 May 2021       paper accepted ※ 23 June 2021       issue date ※ 02 September 2021  
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WEPAB074 A Distributed Sextupoles Lattice for the ALBA Low Emittance Upgrade lattice, emittance, injection, optics 2762
 
  • G. Benedetti, M. Carlà, U. Iriso, Z. Martí, F. Pérez
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
  
  The first lattice studied in 2019 for the ALBA upgrade was a 7BA lattice with two dispersion bumps, for localised chromatic correction. That lattice had limited dynamic aperture and momentum acceptance. In 2020 we started to explore a different approach to find an MBA lattice with distributed chromatic correction that meets the same emittance goal with larger dynamic aperture and momentum acceptance. The choice of the number of bendings per cell, as well as the tuning of the magnet gradients, is carried out by developing a light weight solver that performs both the emittance and chromaticity optimisation of the arcs and the matching of the linear optics in the straight sections. We present the status of the storage ring upgrade studies, the performance of the new developed lattice, together with the issues related with the injection scheme.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB074  
About • paper received ※ 19 May 2021       paper accepted ※ 16 June 2021       issue date ※ 22 August 2021  
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WEPAB121 Design and Simulation of Transparent Injection Upgrade for the CLS Storage Ring injection, storage-ring, kicker, simulation 2885
 
  • P.J. Hunchak, M.J. Boland
    University of Saskatchewan, Saskatoon, Canada
  • D. Bertwistle, M.J. Boland
    CLS, Saskatoon, Saskatchewan, Canada
  
  The Canadian Light Source (CLS) synchrotron uses four fast kicker magnets to inject electrons into the storage ring from a 2.9 GeV booster ring. The injection occurs over several turns of the stored beam, which is also perturbed by the injection kickers. The resultant oscillations of the stored beam can negatively affect beamline experiments, so it is desirable to implement an injection scheme which does not disturb the stored beam. Injection schemes of this type allow for transparent injection and are beneficial for planned top-up operations of the CLS storage ring. Many alternative injection techniques were examined as they apply to the CLS storage ring. Pulsed multipole magnets and a non-linear kicker (NLK) are the most viable options for integration with the current ring. Non-linear kicker designs are also being considered for the proposed CLS2 and studying the NLK in the limitations of the current machine provides insight to guide the work on the new machine. Simulation with the accelerator code ELEGANT shows the viability of the non-linear kicker design as developed at BESSY, MAX IV and SOLEIL for transparent injection at the CLS.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB121  
About • paper received ※ 19 May 2021       paper accepted ※ 16 July 2021       issue date ※ 01 September 2021  
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WEPAB205 XiPAF Synchrotron Slow Extraction Commissioning extraction, experiment, synchrotron, proton 3106
 
  • W.B. Ye, X. Guan, Y. Li, X.Y. Liu, M.W. Wang, X.W. Wang, Y. Yang, H.J. Yao, H.J. Zeng, S.X. Zheng
    TUB, Beijing, People’s Republic of China
  • W.L. Liu, D. Wang, M.C. Wang, Z.M. Wang, Y. Yang, M.T. Zhao
    NINT, Shannxi, People’s Republic of China
  
  Xi’an 200 MeV Proton Application Facility (XiPAF) is a project to fulfill the need for the experimental simulation of the space radiation environment. It comprises a 7 MeV H− linac, a 60~230 MeV proton synchrotron, and experimental stations. Slow extraction commissioning for 60 MeV proton beam in XiPAF synchrotron has been finished. After commissioning, the maximal experiment extraction efficiency with the RF-knockout (RF-KO) method can up to 85%. The reason for beam loss has been analyzed and presented in this paper. Besides, an experiment of multiple energy extraction has been conducted in XiPAF synchrotron. The proton beams of 3 different energies were successfully extracted in 1.54 s.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB205  
About • paper received ※ 18 May 2021       paper accepted ※ 07 July 2021       issue date ※ 31 August 2021  
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WEPAB263 Complex Unit Lattice Cell for Low-Emittance Synchrotrons lattice, emittance, focusing, synchrotron 3254
 
  • Z.L. Ren, Z.H. Bai, J.J. Tan, L. Wang, H. Xu, P.H. Yang
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
  
  To reach the real diffraction-limited emittance, it is generally required to increase the number of bends in multi-bend achromat (MBA) lattices that are used in the designs of fourth-generation synchrotron light sources. For an MBA lattice with distributed chromatic correction, more bends mean much tighter space and much stronger magnets. Inspired by the hybrid MBA lattice concept, in this paper we propose a new lattice concept called complex unit lattice cell, which can save space and reduce magnet strengths. A 17BA lattice based on the complex unit cell concept is designed for a 3 GeV synchrotron light source with a circumference of 537.6 m, which reaches a natural emittance of about 21 pm·rad. Comparison is also made between this 17BA lattice and the 17BA lattice with distributed chromatic correction to demonstrate the merit of the complex unit cell concept.  
poster icon Poster WEPAB263 [1.279 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB263  
About • paper received ※ 16 May 2021       paper accepted ※ 02 July 2021       issue date ※ 12 August 2021  
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THPAB016 Revisit of Nonlinear Dynamics in Hénon Map Using Square Matrix Method resonance, lattice, site, dynamic-aperture 3788
 
  • Y. Hao, K.J. Anderson
    FRIB, East Lansing, Michigan, USA
  • L.H. Yu
    BNL, Upton, New York, USA
  
  Funding: Work supported by the Accelerator Stewardship program, award number DE-SC0019403 with the U.S. Department of Energy
Hénon map (2D or 4D) represents a thin lens sextupole in an otherwise linear lattice and had been well studied for many decades. We revisit the nonlinear properties of the Hénon map with the aid of the square matrix method and Arnold theorem, including acquiring the resonance structure and amplitude-dependent frequency. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB016  
About • paper received ※ 17 May 2021       paper accepted ※ 12 July 2021       issue date ※ 17 August 2021  
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THPAB073 Study of Seven-Bend-Achromat Lattice Option for Half lattice, emittance, storage-ring, octupole 3926
 
  • J.H. Xu, Z.H. Bai, Z.L. Ren, J.J. Tan, P.H. Yang
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
  • Q. Zhang
    INEST, Hefei, People’s Republic of China
  
  A seven-bend-achromat (7BA) storage ring lattice design for Hefei Advanced Light Facility (HALF) with a beam energy of 2.2 GeV and a circumference of 388.8 m is presented. The 7BA lattice is designed with the combined function bends and reverse bends which has a natural emittance of about 67 pm·rad. Two lattice candidates with different tunes have been selected. One lattice has better nonlinear dynamic performance for off-axis injection. The other lattice provides lower beta functions at the center of straight sections. The results of these studies are discussed in this paper.  
poster icon Poster THPAB073 [1.146 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB073  
About • paper received ※ 15 May 2021       paper accepted ※ 28 July 2021       issue date ※ 16 August 2021  
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THPAB090 Progress with the Diamond-II Storage Ring Lattice storage-ring, lattice, emittance, injection 3973
 
  • H. Ghasem, I.P.S. Martin, B. Singh
    DLS, Oxfordshire, United Kingdom
  
  Building on the CDR proposal for the Diamond-II storage ring, a number of changes have been implemented to improve the performance of the lattice. Firstly, anti-bend magnets have been utilized to provide additional control over the dispersion function, and an improved symmetrization in the phase advance between the sextupoles was found to be beneficial for the dynamic aperture. Furthermore, the longitudinal variable bends have been tailored to reduce the emittance and have had transverse gradient added to improve the optics control in the mid-straights. In the absence of IDs, the current design provides 161 pm electron beam emittance, reducing to 139 pm once all effects are taken into account. The dynamic aperture is large enough to support an off-axis injection scheme using a nonlinear kicker and has a lifetime greater than 4 h. In this paper, the main parameters and magnet specifications for the Diamond-II lattice are provided. The related linear and non-linear beam dynamics issues are discussed, along with the impact of IDs.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB090  
About • paper received ※ 19 May 2021       paper accepted ※ 17 June 2021       issue date ※ 26 August 2021  
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THPAB123 Pytomic: A Python Tool for Polarized Atomic Beam Tracking simulation, detector, polarization, target 4002
 
  • J.L. Martinez Marin, W. Armstrong, B.M. Mustapha
    ANL, Lemont, Illinois, USA
  
  Funding: This work was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357 through ANL’s LDRD program.
Pytomic is a new tool for the simulation and analysis of atomic beams through magnetic systems. It is written in Python and based on the same fundamentals as other particle tracking codes but for atomic beams instead of charged beams. In this case, the manipulation and control of neutral atomic beams is via a force due to the spin interacting with a magnetic field gradient. An object-oriented tool was developed to aid in the design of a beamline through the manipulation of modular elements. The Python language allowed for a smooth implementation and kept the code clear and simple. The primary purpose of developing this code was to have a tool to design, simulate, and optimize a Breit-Rabi Polarimeter to measure the polarization of an atomic beam. Therefore, different set-ups with different magnets need to be simulated and optimized for direct comparison. In addition to simulation and tracking modules, a new data analysis module was developed to be able to quickly analyze simulation results, gaining insight from each iteration of the simulation, leading to an efficient and rapid design process. Example applications to design polarimeters for atomic beams will be presented. 		 
poster icon Poster THPAB123 [7.765 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB123  
About • paper received ※ 20 May 2021       paper accepted ※ 21 June 2021       issue date ※ 27 August 2021  
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