MC2: Photon Sources and Electron Accelerators
A05 Synchrotron Radiation Facilities
Paper Title Page
MOXX01
 Scientific Opportunities for 4th Generation Storage Ring Light Sources  
 
  • H. Westfahl Jr.
    LNLS, Campinas, Brazil
  
  Funding: The Sirius project is funded by the Brazilian Federal Government via a contract with the Ministry of Science, Technology & Innovation
The new generation of storage ring light sources based on Multi-Bend Achromat (MBA) magnet lattice provides electron beams with size and divergence that match the phase space of the x-ray photons, approximating their so-called diffraction limit. The dramatic increase in brightness and transversely coherent photon flux from such improvement, combined with advances in mechatronics, optics, detectors, and computing, open new avenues of research within spatiotemporal scales previously inaccessible. This talk will present exciting scientific opportunities to explore the characteristics of biological, hierarchical, and condensed matter systems on these new light sources and particularly on Sirius, the new Brazilian 4th generation storage ring. 		 
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MOXB01
 Progress Towards Realisation of Steady-State Microbunching at the Metrology Light Source  
 
  • J. Feikes, A. Kruschinski, J. Li, A.N. Matveenko, Y. Petenev, M. Ries
    HZB, Berlin, Germany
  • A. Chao
    SLAC, Menlo Park, California, USA
  • X.J. Deng, W.-H. Huang, C.-X. Tang, L.X. Yan
    TUB, Beijing, People’s Republic of China
  • A. Hoehl, R. Klein
    PTB, Berlin, Germany
  
  Coherent radiation is a powerful scheme for storage-ring-based synchrotron radiation sources as its intensity increases with the square of the number of radiating electrons. Formation of bunches or sub-bunches shorter than the radiation wavelength, i.e., microbunching, is necessary for the radiation from different electrons to add in phase and therefore cohere. Recently at the MLS it has been shown that in dedicated isochronous optics an electron beam energy modulation induced by an externally applied 1064-nm-wavelength laser in an undulator leads to the formation of sub-um microbunches one turn later*, providing the basis for the implementation of steady-state microbunching in electron storage rings to generate high-repetition, high-power coherent radiation. Here we report on the recent progress and continuing development of this experiment.
Deng, X., Chao, A., Feikes, J. et al. Experimental demonstration of the mechanism of steady-state microbunching. Nature 590, 576-579 (2021). https://doi.org/10.1038/s41586-021-03203-0 		 
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MOPAB036 Different Operation Regimes at the KIT Storage Ring KARA (Karlsruhe Research Accelerator) 163
 
  • A.I. Papash, M. Brosi, E. Huttel, A. Mochihashi, A.-S. Müller, R. Ruprecht, P. Schreiber, M. Schuh, N.J. Smale
    KIT, Karlsruhe, Germany
  
  The KIT storage ring KARA operates in a wide energy range from 0.5 to 2.5 GeV. Different operation modes have been implemented at KARA, so far, the double-bend achromat (DBA) lattice with non-dispersive straight sections, the theoretical minimum emittance (TME) lattice with distributed dispersion, different versions of low-compaction factor optics with highly stretched dispersion function. Short bunches of a few ps pulse width are available at KARA. Low-alpha optics has been simulated, tested and implemented in a wide operational range of the storage ring and is now routinely used at 1.3 GeV for studies of beam bursting effects caused by coherent synchrotron radiation in the THz frequency range. Different non-linear effects, in particular residual high-order components of the magnetic field, generated in high-field superconducting wigglers have been studied and cured. Based on good agreement between computer simulations and experiments, a new operation mode at high vertical tune was implemented. The beam performance during user operation as well as at low-alpha regimes has been improved. A specific optic with negative compaction factor was simulated, tested and is in operation.  
poster icon Poster MOPAB036 [1.477 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB036  
About • paper received ※ 13 May 2021       paper accepted ※ 08 June 2021       issue date ※ 29 August 2021  
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MOPAB048 Robust Design and Control of the Nonlinear Dynamics for BESSY-III 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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MOPAB053 Progress of Lattice Design and Physics Studies on the High Energy Photon Source 229
 
  • Y. Jiao, Y. Bai, X. Cui, C.C. Du, Z. Duan, Y.Y. Guo, P. He, X.Y. Huang, D. Ji, H.F. Ji, S.C. Jiang, B. Li, C. Li, J.Y. Li, N. Li, X.Y. Li, P.F. Liang, C. Meng, W.M. Pan, Y.M. Peng, Q. Qin, H. Qu, S.K. Tian, J. Wan, B. Wang, J.Q. Wang, N. Wang, Y. Wei, G. Xu, H.S. Xu, F. Yan, C.H. Yu, Y.L. Zhao
    IHEP, Beijing, People’s Republic of China
  • X.H. Lu
    IHEP CSNS, Guangdong Province, People’s Republic of China
  
  Funding: Work supported by High Energy Photon Source (HEPS), a major national science and technology infrastructure and NSFC (11922512)
The High Energy Photon Source (HEPS) is a 34-pm, 1360-m storage ring light source being built in the suburb of Beijing, China. The HEPS construction started in mid-2019. While the physics design has been basically determined, modifications on the HEPS accelerator physics design have been made since 2019, in order to deal with challenges emerging from the technical and engineering designs. In this paper, we will introduce the new storage ring lattice and injector design, and also present updated results of related physics issues, including impedance and collective effects, lattice calibration, insertion device effects, injection design studies, etc. 		 
poster icon Poster MOPAB053 [0.699 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB053  
About • paper received ※ 10 May 2021       paper accepted ※ 24 May 2021       issue date ※ 17 August 2021  
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MOPAB055 Generation of Coherent Attosecond X-ray Pulses in the Southern Advanced Photon Source 237
 
  • W. Liu, Y. Zhao
    IHEP CSNS, Guangdong Province, People’s Republic of China
  • Y. Jiao, S. Wang
    IHEP, Beijing, People’s Republic of China
  
  Southern Advanced Photon Source (SAPS) is a fourth-generation storage ring light source that has been considered for construction in Guangdong province of China, adjacent to the China Spallation Neutron Source. As a low-emittance storage ring, the natural emittance of SAPS is below 100 pm. One of the benefits is that the brightness is about 2 orders high than 3rd generation light sources. However, like many other storage ring-based light sources, the time resolution is limited by the electron bunch length in the range of picoseconds. In this work, we propose a new scheme for the generation of coherent attoseconds X-ray pulses with a high repetition rate in SAPS. A numerical demonstration of the scheme is presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB055  
About • paper received ※ 17 May 2021       paper accepted ※ 26 May 2021       issue date ※ 26 August 2021  
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MOPAB058 Swap-Out Safety Tracking for the Advanced Photon Source Upgrade 249
 
  • M. Borland, J.S. Downey, M.S. Jaski
    ANL, Lemont, Illinois, USA
  
  Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The Advanced Photon Source upgrade will operate in swap-out mode, which is similar to top-up but involves complete replacement of individual depleted bunches in a single shot. As with top-up, safety is a concern given that this process will take place with beamline shutters open. We describe the methods used to model swap-out safety, including creation and validation of a full ring lattice based on 3D field maps. We also describe a new method of implementing complex, intersecting channels for electron beams and photon beams, as well as a method of easily identifying potentially dangerous stray particles. Numerous potential errors (e.g., magnet shorts) were modeled, giving a reliable indication of performance of proposed stored beam and magnet interlocks. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB058  
About • paper received ※ 14 May 2021       paper accepted ※ 28 May 2021       issue date ※ 29 August 2021  
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MOPAB061 Comparison Simulation Results of the Collimator Aperture in HEPS Storage Ring 257
 
  • Y.L. Zhao, Y. Jiao, N. Li
    IHEP, Beijing, People’s Republic of China
  
  The High Energy Photon Source (HEPS) is a 6 GeV diffraction-limited storage ring light source, which is under construction and planned to be in operation in 2025. To protect the sensitive elements from being damaged and reduce the radiation level of the site, collimators will be installed in the storage ring to localize the particle losses. The Touschek scattering is the main cause of particle losses during daily nominal operations. Based on the elegant simulations, we evaluate the physical design of the collimators, especially analysis the collimator performance with different collimator apertures. The simulation results will be introduced in this paper.  
poster icon Poster MOPAB061 [0.701 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB061  
About • paper received ※ 13 May 2021       paper accepted ※ 17 August 2021       issue date ※ 21 August 2021  
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MOPAB062 A Single Dipole Source for Broad-Band Soft Photon Beamlines in Diamond-II 261
 
  • M. Apollonio, G. Cinque, H. Ghasem, A.N. Jury, I.P.S. Martin, R. Rambo
    DLS, Oxfordshire, United Kingdom
  
  Diamond-II is a project based at Diamond Light Source for an upgrade towards a Storage Ring characterized by a reduction of a factor 20 in its natural emittance and a doubling of the number of straight sections. At Diamond-II the majority of existing beamline capacity should be maintained, while enhancing their performance thanks to the increase in brightness at the source points. The substantial modification of the lattice imposes a likewise re-design of the broad-band sources, presently based on standard dipoles. In this paper we discuss a possible solution for the IR/THz beamline B22 operating within a photon energy range between 1meV and 1eV. This proposal, ideal for low critical energy and single source point sources, entails the insertion of a dipole in one of the newly created mid-cell straights of the machine, while reducing the bending power of the nearby gradient dipoles. After performing the linear matching of the lattice, reproducing a comparable phase advance in the modified cell, we studied the non-linear dynamics of the system. Comparison of the main observables (Dynamic Aperture, Injection Efficiency and Lifetime) with the baseline case is discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB062  
About • paper received ※ 18 May 2021       paper accepted ※ 28 May 2021       issue date ※ 12 August 2021  
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MOPAB063 Commissioning Strategy for Diamond-II 265
 
  • M. Apollonio, R.T. Fielder, H. Ghasem, I.P.S. Martin
    DLS, Oxfordshire, United Kingdom
  
  At Diamond Light Source we are working on the upgrade towards a machine aimed at a factor 20 reduction in emittance and an increase of the capacity for beamlines. Crucially the success of the programme depends on the ability to inject and capture the electrons in the storage ring, and finally reach control of beam alignment and the linear optics. The paper presents the series of strategies adopted to achieve the commissioning of the machine, from the threading procedure ensuring the first turn of the electron beam, to the orbit corrections in the storage ring. Beam based alignment of the quadrupoles and skew quadrupoles is illustrated and restoration of the linear optics (LOCO) for the storage ring is presented. Main performance parameters (Dynamic Apertures, Injection Efficiency and Lifetime) are calculated to evaluate the performance of the commissioned lattices.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB063  
About • paper received ※ 18 May 2021       paper accepted ※ 28 May 2021       issue date ※ 14 August 2021  
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MOPAB065 Optimization of the Lattice Replacement Options for the Next Generation Australian Synchrotron 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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MOPAB068 Collective Effects Studies for the SOLEIL Upgrade 274
 
  • A. Gamelin, D. Amorim, P. Brunelle, W. Foosang, A. Loulergue, L.S. Nadolski, R. Nagaoka, R. Ollier, M.-A. Tordeux
    SOLEIL, Gif-sur-Yvette, France
  
  The SOLEIL upgrade project aims to replace the actual SOLEIL storage ring by a 4th generation light source. The project has just finished its conceptual design report (CDR) phase*. Compared to the SOLEIL storage ring, the upgraded storage ring design includes many new features of 4th generation light sources that will impact collective effects, such as reduced beam pipe apertures, a smaller momentum compaction factor and the presence of harmonic cavities (HC). To mitigate them, we rely on several damping mechanisms provided by the synchrotron radiation, the transverse feedback system, and the HC (Landau damping and bunch lengthening). This article presents a first estimate of the collective effects impact of the upgraded design.
* Conceptual Design Report: Synchrotron SOLEIL Upgrade, 2021, in press. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB068  
About • paper received ※ 17 May 2021       paper accepted ※ 02 June 2021       issue date ※ 12 August 2021  
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MOPAB071 Progress with the Booster Design for the Diamond-II Upgrade 286
 
  • I.P.S. Martin, C. Christou, M.P. Cox, R.T. Fielder, J. Kallestrup, A. Shahveh, W. Tizzano
    DLS, Oxfordshire, United Kingdom
  • A.D. Brynes, J.K. Jones, B.D. Muratori, H.L. Owen
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  
  Efficient injection into the Diamond-II storage ring [*, **] will require an emittance and bunch length substantially below the values produced from the existing booster. Whilst an earlier design for a replacement based on TME cells was able to meet the target values of <30 nm.rad and <40 ps respectively [***, ****], several technical constraints have led to a rethink of this solution. The revised booster lattice utilises a larger number of cells based on combined-function magnets with lower peak fields that still meets the emittance and bunch length goals. In addition, the new ring has been designed to have low impedance to maximise the extracted charge per shot. In this paper we describe the main features of the lattice, present the status of the engineering design and quantify the expected performance.
*Diamond-II Conceptual Design Report, Diamond Light Source
**H. Ghasem et al, these proceedings
***I. Martin, R. Bartolini, J.Phys.:Conf. Ser., 1067, 032005
****I. Martin et al, IPAC 2019, WEPMP042 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB071  
About • paper received ※ 18 May 2021       paper accepted ※ 31 May 2021       issue date ※ 02 September 2021  
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MOPAB072 Single-Bunch Thresholds for the Diamond-II Storage Ring 290
 
  • T. Olsson, R.T. Fielder
    DLS, Oxfordshire, United Kingdom
  
  The proposed Diamond Light Source upgrade will see the storage ring replaced with a multibend achromat lattice, increasing the capacity of the facility whilst reducing the emittance and providing higher brightness for the users. As part of the design work, tracking studies have been performed to determine the single-bunch thresholds including both the resistive-wall and geometric contributions to the impedance. As the machine design also foresees a third order harmonic cavity, the paper also provides an initial assessment of the effects of bunch lengthening on the single-bunch thresholds.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB072  
About • paper received ※ 18 May 2021       paper accepted ※ 01 June 2021       issue date ※ 23 August 2021  
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MOPAB073 Beam Loss Simulations During Beam Dumping in Heps 294
 
  • X. Cui, Y. Jiao, Y.L. Zhao
    IHEP, Beijing, People’s Republic of China
  
  The High Energy Photon Source (HEPS) is a 6 GeV storage ring light source under construction in China. Several collimators installed in the vacuum chamber will be used as beam dump in the storage ring operation. Preliminary simulations showed that the temperature rise caused by the beam power deposited on the collimators will far exceed the melting point of the collimator material. In order to cure this problem, special kickers are proposed to be installed in the ring to modulate the beam during beam dumping, thereby increasing the size of the beam hit on the collimators. In this article, some simulation results of the density of particles on the collimators during beam dumping for different HEPS lattice and different kicker parameters are shown.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB073  
About • paper received ※ 17 May 2021       paper accepted ※ 07 June 2021       issue date ※ 31 August 2021  
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MOPAB075 Proposal of the Southern Advanced Photon Source and Current Physics Design Study 300
 
  • S. Wang, J. Chen, L. Huang, Y. Jiao, B. Li, Z.P. Li, W. Liu, S.Y. Xu
    IHEP, Beijing, People’s Republic of China
  • Y. Han, X.H. Lu, Y. Zhao
    IHEP CSNS, Guangdong Province, People’s Republic of China
  • X. Liu
    Department of Energy Sciences, Tokyo Institute of Technology, Yokohama, Japan
  
  It has been considered to build a mid-energy fourth-generation storage ring light source neighbouring the China Spallation Neutron Source, in Guangdong Province, the south of China. The light source is named the Southern Advanced Photon Source (SAPS). Preliminary physics design studies on the SAPS have been implemented for a few years. In this paper, we will describe considerations of technical roadmap and key parameter choice for this light source, and introduce the up-to-date lattice designs and related physics studies on the SAPS.  
poster icon Poster MOPAB075 [1.689 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB075  
About • paper received ※ 12 May 2021       paper accepted ※ 20 May 2021       issue date ※ 21 August 2021  
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MOPAB077 Anomaly Detection in Accelerator Facilities Using Machine Learning 304
 
  • A. Das
    Stanford University, Stanford, California, USA
  • M. Borland, L. Emery, X. Huang, H. Shang, G. Shen
    ANL, Lemont, Illinois, USA
  • D.F. Ratner
    SLAC, Menlo Park, California, USA
  • R.M. Smith, G.M. Wang
    BNL, Upton, New York, USA
  
  Synchrotron light sources are user facilities and usually run about 5000 hours per year to support many beamlines operations in parallel. Reliability is a key parameter to evaluate machine performance. Even many facilities have achieved >95% beam reliability, there are still many hours of unscheduled downtime and every hour lost is a waste of operation costs along with a big impact on individual scheduled user experiments. Preventive maintenance on subsystems and quick recovery from machine trips are the basic strategies to achieve high reliability, which heavily depends on experts’ dedication. Recently, SLAC, APS, and NSLS-II collaborated to develop machine-learning-based approaches aiming to solve both situations, hardware failure prediction and machine failure diagnosis to find the root sources. In this paper, we report our facility operation status, development progress, and plans.  
poster icon Poster MOPAB077 [1.240 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB077  
About • paper received ※ 16 May 2021       paper accepted ※ 14 June 2021       issue date ※ 01 September 2021  
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MOPAB079 Experience of the First Six Years Operations and Plans in NSlS-II 308
 
  • G.M. Wang
    BNL, Upton, New York, USA
  
  NSLS-II is a 3 GeV third-generation synchrotron light source at BNL. The storage ring was commissioned in 2014 and began its routine operations in the December of the same year. Since then, we have been continuously installing and commissioning new insertion devices, their front-ends, and beamlines. At this point, the facility hosts 28 operating beamlines from various radiation sources, including damping wiggler, IVU, EPU, 3PW, and bending magnets for infrared beamlines. Over the past six years, the storage ring performance continuously improved, including 500 mA with limited insertion devices close due to RF power limitation and routinely 400 mA top off operation, >95% operation reliability, maintenance of beam motion short- and long-term stability. In this paper, we report NSLS-II accelerator operations experience and plans for future facility developments.  
poster icon Poster MOPAB079 [2.064 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB079  
About • paper received ※ 17 May 2021       paper accepted ※ 21 June 2021       issue date ※ 25 August 2021  
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MOPAB081 Feasibility Study of Using Multipole Injection Kicker (MIK) and Sextupole for TPS Injection 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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MOPAB084 Acceptance Tests and Installation of the IVU and Front End for the XAIRA Beamline of ALBA 318
 
  • J. Campmany, J. Marcos, V. Massana
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
  
  XAIRA is a new beamline being built at ALBA synchrotron for macromolecular crystallography (MX) devoted to the study of small bio crystals. It aims at providing a full beam with a size of 3x1 µm2 FWHM (hxv) and flux of >3·1012 ph/s (250 mA in Storage Ring) at 1 Å wavelength (12.4 keV) to tackle MX projects for which only tiny (<10 μm) or imperfect crystals are obtained. Besides, XAIRA aims at providing photons at low energies, down to 4 keV, to support MX experiments exploiting the anomalous signal of the metals naturally occurring in proteins (native phasing), which is enhanced in the case of small crystals and long wavelengths. To this end, an in-vacuum undulator has been built by a consortium between Kyma and Research Instruments companies. In this paper, we present the results of the Site Acceptance Tests made at ALBA using a new bench developed to measure closed structures, and also the steps done for its installation in the ALBA tunnel.  
poster icon Poster MOPAB084 [1.715 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB084  
About • paper received ※ 11 May 2021       paper accepted ※ 20 May 2021       issue date ※ 25 August 2021  
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MOPAB085 Design and Fabrication of a Short Multipole Wiggler and the Front End for the New ALBA Beamline FAXTOR 321
 
  • J. Campmany, J. Marcos, V. Massana
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
  
  FAXTOR is a new hard XR tomography beam line that is being built at ALBA in order to fulfil the needs that cannot be currently covered by the MISTRAL VUV and soft XR beamline. This beam line needs a small source size as well higher than 1012 Photons per second through an aperture of 4x1 mm2 in the whole range 5 to 60 keV, for a current of 250 mA in Storage Ring with source size maintained below 310 µm horizontal and 25 µm vertical. The contract was awarded to AVS-US Company. In this paper we present the design finally selected as well as the preliminary design carried out by manufacturer to implement the conceptual model designed by ALBA.  
poster icon Poster MOPAB085 [1.879 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB085  
About • paper received ※ 11 May 2021       paper accepted ※ 20 May 2021       issue date ※ 31 August 2021  
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MOPAB086 Design of Front End and a 3-Pole-Wiggler as a Photon Source for BEATS Beamline at SESAME 324
 
  • J. Campmany, J. Marcos
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
  • M. Al Nadjawi, M. Attal, G. Lori
    SESAME, Allan, Jordan
  • I. Cudin
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • S. Guiducci
    INFN/LNF, Frascati, Italy
  • P. Van Vaerenbergh
    ESRF, Grenoble, France
  
  BEATS is an international collaboration funded by EU in order to design and implement an XR tomography beam line in SESAME Jordanian synchrotron. ALBA contribution consists in the design of the photon source and the Front End elements. In this paper we present the conceptual designs of both the 3-pole wiggler uses as photon source as well as the Front End elements designed for the beamline.  
poster icon Poster MOPAB086 [2.306 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB086  
About • paper received ※ 11 May 2021       paper accepted ※ 21 May 2021       issue date ※ 17 August 2021  
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MOPAB087 Design of a Multi-Bunch Feedback Kicker in SPEAR3 327
 
  • K. Tian, J.B. Langton, NL. Parry, J.A. Safranek, J.J. Sebek
    SLAC, Menlo Park, California, USA
  
  The new Multi-bunch feedback kickers have been designed to replace the current device loaned from ALS. In this paper, we first present the specification of the kickers based on the beam physics requirements. Then the mechanical design of the kicker is elaborated. Numerical simulations, both in time domain and in frequency domain, are conducted for evaluating the shunt impedance and beam coupling impedance of the kicker. Surface heating induced from the beam or the external source is estimated from the numerical results as well.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB087  
About • paper received ※ 19 May 2021       paper accepted ※ 11 June 2021       issue date ※ 01 September 2021  
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MOPAB088 Beam-Based Measurement on the Performance of Ferrite Dampers in an In-Vacuum Undulator 331
 
  • K. Tian, A. Ringwall, J.J. Sebek
    SLAC, Menlo Park, California, USA
  
  In this paper, we first present the tracking studies for SPEAR3 with the new BL17 ID and estimate its impact on the dynamic aperture of the low emittance lattice. Then the ferrite dampers installations in the device is briefly reviewed. After that, we will show that, based on beam-based measurements, the performance of the dampers is as being expected from earlier numerical studies.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB088  
About • paper received ※ 19 May 2021       paper accepted ※ 18 June 2021       issue date ※ 24 August 2021  
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MOPAB089 Effect of Different Models of Combined-function Dipoles on the HEPS Parameters 335
 
  • Y.Y. Guo, Y. Jiao, N. Li
    IHEP, Beijing, People’s Republic of China
  
  The high energy photon source (HEPS) is a 6 GeV, kilometer-scale storage ring light source being built in Beijing, China. In the current ring lattice, the combined-function dipoles are used and assumed to have constant dipole field. However, in the actual magnet design, an eccentrically placed quadrupole is adopted, in which the bending field along the trajectory is not constant. In this paper, we will present the effect of the two models of combined-function dipoles on the parameters of the storage ring.  
poster icon Poster MOPAB089 [0.590 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB089  
About • paper received ※ 13 May 2021       paper accepted ※ 25 May 2021       issue date ※ 27 August 2021  
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MOPAB090 Status of HEPS Insertion Devices Design 339
 
  • X.Y. Li, Y. Jiao, H.H. Lu, S.K. Tian
    IHEP, Beijing, People’s Republic of China
  
  HEPS is a 4th generation light source with the energy of 6 GeV and ultralow emittance of 34 pm.rad. A total of 14 beamlines with 19 insertion devices has been planned in the first phase, including 6 cryogenic undulators, 5 in-vacuum undulators, and two special non-planar IDs. The schemes and parameters of all the IDs are planned to be determined in this year. We report on the status of the design of these IDs and their effects on beam dynamics.  
poster icon Poster MOPAB090 [0.633 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB090  
About • paper received ※ 13 May 2021       paper accepted ※ 01 July 2021       issue date ※ 10 August 2021  
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MOPAB091 Injection Section Upgrading with the Septum-Magnet Replacement in KEK-PF Ring 342
 
  • C. Mitsuda, K. Harada, N. Higashi, T. Honda, Y. Kobayashi, H. Miyauchi, S. Nagahashi, N. Nakamura, T. Nogami, T. Obina, M. Tadano, R. Takai, H. Takaki, Y. Tanimoto, T. Uchiyama, A. Ueda
    KEK, Ibaraki, Japan
  
  In 2015, the water leakage happened at the cooling pipe of the in-vacuum septum magnet installed into the injection point. Because the maintenance of the leakage needed the total replacement of the magnet, the water circulation was stopped permanently, and accordingly, the light absorber was installed upstream in the storage ring to prevent the synchrotron light of the bending magnet from coming to the septum wall. This treatment temporally worked well, but the beam injection efficiency was decreased to about 30% due to the physical aperture narrowed by the absorber. With the desired replacement of septum magnet to maintainable out-vacuum type, the injection section upgrading was simultaneously planned to recover and improve the injection efficiency. In this upgrade, the injection beam is closed to the stored beam more than before by adapting the thinner septum structure as a way to improve the injection efficiency. And some new ideas are introduced in the part of monitor and beam duct, for example, realtime beam monitor, thinner Inconel duct. The detailed design of the upgraded injection section and technical points will be reviewed in this conference.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB091  
About • paper received ※ 19 May 2021       paper accepted ※ 26 May 2021       issue date ※ 02 September 2021  
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MOPAB092 Project of Wuhan Photon Source 346
 
  • H.H. Li, Y. Deng, J.H. He, Y. Nie, L. Tang, J. Wang, Y.X. Zhu
    IAS, Wuhan City, People’s Republic of China
  
  Wuhan Photon Source (WHPS) has been designed as a fourth-generation light source, which consists of a low energy storage ring (1.5 GeV), a medium energy storage ring (4.0 GeV), and a linac working as a full energy injector. It has been planned to build the low energy light source first as the Phase I project, and then the medium energy light source after its completion. The low energy storage ring has been optimized with the main design parameters as following: An 8-cell, 500 mA storage ring, with a circumference of 180 m and nature emittance 238.4 pm-rad. Based on hybrid-7BA lattice structure, it reaches the soft X-ray diffraction limit. And at the middle of each cell, a 3.5 T superB magnet is used to extend the photon energy to the hard X-ray region. The swap-out injection is chosen due to the small dynamic aperture and a full energy S-band LINAC will be used as its injector. A 3rd harmonic cavity is designed for bunch lengthening to keep a sufficient lifetime. More details of the WHPS phase I project will be described in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB092  
About • paper received ※ 10 June 2021       paper accepted ※ 23 June 2021       issue date ※ 24 August 2021  
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MOPAB093 Operational Status of Photon Factory Light Sources 350
 
  • T. Honda, Y. Kobayashi, C. Mitsuda, S. Nagahashi, R. Takai, H. Takaki
    KEK, Ibaraki, Japan
  
  One of the recent topics of Photon Factory light sources, PF-ring and PF-AR, is a construction of a GeV-class beamline for testing detectors at the PF-AR. The bremsstrahlung photons generated by a thin carbon wire are brought to a copper target to generate e+e− pairs. Sufficient count rates can be expected when the thin wire touching halo of the stored beam, and the test beamline can be used without disturbing the synchrotron radiation experiments. In addition to the usual 6.5-GeV operation, a low-energy operation at 5-GeV was started recently at PF-AR to secure operation time by saving electricity costs. At the PF-ring, the injection section has been upgraded with the septum-magnet replacement. By the top-up injection and improved bunch feedback, the hybrid-fill mode operation has become convenient for both single-bunch users and multi-bunch users, and about 30% or 40% of the user time is scheduled as the hybrid-fill mode now.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB093  
About • paper received ※ 21 May 2021       paper accepted ※ 25 May 2021       issue date ※ 13 August 2021  
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MOPAB095 Concept Design for the CLS2 Accelerator Complex 354
 
  • M.J. Boland, P.J. Hunchak
    University of Saskatchewan, Saskatoon, Canada
  • C.K. Baribeau, D. Bertwistle, J.M. Patel, H. Shaker, X. Shen, M.J. Sigrist
    CLS, Saskatoon, Saskatchewan, Canada
  • F. Le Pimpec
    EuXFEL, Schenefeld, Germany
  • E.J. Wallén
    LBNL, Berkeley, California, USA
  
  The Canadian Light Source has been in operation since 2005 and is now looking at a design concept to upgrade to a fourth generation storage ring. A brief overview is given of a possible accelerator complex layout, including some details on the lattice design and injection system. A full energy linac is being explored as an option for top-up injection and to future proof the facility for a potential FEL upgrade in the future.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB095  
About • paper received ※ 23 May 2021       paper accepted ※ 28 July 2021       issue date ※ 13 August 2021  
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MOPAB096 Rocking Curve Imaging Experiment at SSRL 10-2 Beamline 357
 
  • A. Halavanau, R. Arthur, B. Johnson, J.P. MacArthur, G. Marcus, R.A. Margraf, Z. Qu, T. Rabedeau, T. Sato, C.J. Takacs, D. Zhu
    SLAC, Menlo Park, California, USA
  
  Stanford Synchrotron Radiation Lightsource (SSRL) serves a wide scientific community with its variety of X-ray capabilities. Recently, we have employed a wiggler source located at beamline 10-2 to perform high resolution rocking curve imaging (RCI) of diamond and silicon crystals. In-house X-ray RCI capability is important for the upcoming cavity-based x-ray source development projects at SLAC, such as cavity-based XFEL (CBXFEL) and X-ray laser oscillator (XLO). In this proceeding, we describe theoretical considerations, and provide experimental results, validating the design of our apparatus. We also provide a plan for future improvements of the RCI@SSRL program.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB096  
About • paper received ※ 19 May 2021       paper accepted ※ 27 July 2021       issue date ※ 10 August 2021  
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MOPAB102 CSR Impedance in HEPS Storage Ring 379
 
  • H.S. Xu, X.Y. Li, N. Wang
    IHEP, Beijing, People’s Republic of China
  
  High Energy Photon Source (HEPS) is under construction in Beijing, China. The relatively complete impedance model has been built up based on the element-by-element impedance calculation. However, Coherent Synchrotron Radiation (CSR) impedance, which might affect the longitudinal performance of the beam, was not included in the impedance model of the HEPS storage ring in the preliminary design stage. For completeness, we would like to take the CSR impedance into consideration. The most important contributions to the total CSR impedance come from the bending magnets and insertion devices. We therefore calculate the CSR impedance from both above mentioned elements in HEPS storage ring. The influence of the CSR impedance on the microwave instability threshold is studied and presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB102  
About • paper received ※ 17 May 2021       paper accepted ※ 18 June 2021       issue date ※ 27 August 2021  
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MOPAB103 Study of Transverse Oscillation Coupling and Possibility of Its Minimization in SKIF (Novosibirsk) 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 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. 		 
poster icon Poster MOPAB106 [0.918 MB]  
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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MOPAB107 RF Plans for the Diamond-II Upgrade 391
 
  • C. Christou, P. Gu, P.J. Marten, S.A. Pande, A.F. Rankin
    DLS, Oxfordshire, United Kingdom
  
  The RF system for the proposed Diamond-II upgrade will be based on normal-conducting EU HOM-damped cavities powered by high powered solid state amplifiers and controlled by digital low level RF systems built on the microTCA platform. Reasons for these design choices are discussed, and experience of the selected technologies in the Diamond-I ring are reviewed. The storage ring will also include a third harmonic cavity, and the different design options for this device are discussed. RF design of the booster ring is presented, and details are given of an upgraded linac and gun design intended to improve the charge delivered for top-up.  
poster icon Poster MOPAB107 [1.703 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB107  
About • paper received ※ 18 May 2021       paper accepted ※ 20 May 2021       issue date ※ 12 August 2021  
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MOPAB108 ESRF-EBS 352.37 MHz Radio Frequency System 395
 
  • J. Jacob, P.B. Borowiec, A. D’Elia, G. Gautier, V. Serrière
    ESRF, Grenoble, France
  
  The ESRF 352 MHz Radio Frequency (RF) system has been upgraded and tailored to the new 4th Generation Extremely Brilliant Source EBS, that was installed in 2019 and commissioned in 2020. The five former five-cell cavities were replaced with 13 single cell strongly HOM damped cavities that were developed in house, 10 of which are powered from existing 1 MW klystron transmitters. The remaining three cavities are individually fed by three 150 kW solid state amplifiers. All this required a reconstruction in record time of an elaborate WR2300 waveguide network. The low level RF system as well as the cavity and transmitter control system have been rebuilt. The RF design, commissioning and operation experience will be reported, including plans for a 4th harmonic RF system for bunch lengthening to further improve the performance of the new EBS ring.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB108  
About • paper received ※ 19 May 2021       paper accepted ※ 27 May 2021       issue date ※ 02 September 2021  
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MOPAB109 A Lattice for PETRA IV Based on the Combination of Different Arc Cell Designs 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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MOPAB112 A Modified Hybrid 6BA Lattice for the HALF Storage Ring 407
 
  • Z.H. Bai, G.Y. Feng, T.L. He, W. Li, W.W. Li, G. Liu, Z.L. Ren, L. Wang, P.H. Yang, S.C. Zhang, T. Zhang
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
  
  In this paper, we propose a modified hybrid 6BA lattice as the baseline lattice of the Hefei Advanced Light Facility (HALF) storage ring. Similar to the Diamond-II lattice, the proposed lattice cell has one long straight section and one mid-straight section; but the two bend units adjacent to the mid-straight are LGB/RB units (LGB: longitudinal gradient bend, RB: reverse bend), which can give both lower emittance and shorter damping times. The designed HALF storage ring, with an energy of 2.2 GeV and 20 lattice cells, has a natural emittance of about 85 pm·rad.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB112  
About • paper received ※ 15 May 2021       paper accepted ※ 20 May 2021       issue date ※ 01 September 2021  
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MOPAB114 Development of a Decoherence Kicker for the ALS Upgrade Project (ALS-U) 414
 
  • C. Sun, S. De Santis, M.P. Ehrlichman, T. Hellert, T. Oliver, G. Penn, C. Steier, M. Venturini, W.L. Waldron
    LBNL, Berkeley, California, USA
  
  The Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory is upgrading the existing storage-ring lattice to a nine-bend-achromat lattice with on-axis swap-out injection. The upgraded storage ring will provide a highly focused beam of about 10 um in both horizontal and vertical directions with a single bunch train energy of about 60 J at 2.0 GeV. Such a small and intense beam could cause damage to the transfer line vacuum chambers in case of extraction element failures or damage to the storage ring vacuum chamber in case of RF failures. To mitigate these potential damages, a fast kicker magnet (so-called decoherence kicker) will be installed in the ALS-U storage ring and activated to dilute the beam charge density either on a train to be swapped out a few 100s turns before extraction or on the whole beam after RF failures. In this paper, we will present both physics and engineering designs of this decoherence kicker.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB114  
About • paper received ※ 19 May 2021       paper accepted ※ 27 May 2021       issue date ※ 20 August 2021  
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MOPAB116 A Flexible Injection Scheme for the ESRF-EBS 421
 
  • S.M. White, N. Carmignani, L.R. Carver, M. Dubrulle, L. Hoummi, S.M. Liuzzo, M. Morati, T.P. Perron
    ESRF, Grenoble, France
  
  The ESRF-EBS storage ring light source started commissioning in 2019 and successfully resumed users operation in 2020. Due to the smaller emittance and consequently reduced lifetime frequent injections are required that can potentially disturb beam lines experiments. In addition, operating the machine with low beta straight section and reduced insertion devices (ID) gaps are considered, therefore reducing the vertical aperture of the machine. Alternatives to the standard off-axis injection scheme allowing for efficient injection in reduced apertures with minimized perturbations are explored. A flexible layout for potential integration in the ESRF-EBS lattice is proposed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB116  
About • paper received ※ 11 May 2021       paper accepted ※ 27 May 2021       issue date ※ 24 August 2021  
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MOPAB118 The Impact of Short-Range Wakes on Injection Into the ALS-U Accumulator Ring 429
 
  • G. Penn, M.P. Ehrlichman, T. Hellert, C. Steier, C. Sun, M. Venturini, D. Wang
    LBNL, Berkeley, California, USA
  
  Funding: This work was supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DEAC02-05CH11231.
As part of the ALS-U design, bunches with small charge will be added to the accumulator ring in a manner that initially leaves both the stored and injected bunches displaced from the nominal orbit. While the beam current is below instability thresholds, transient effects due to the combination of short-range wake fields and large initial displacements can have an impact on injection efficiency. In this paper, the impact of wake fields on the two bunches is detailed using the elegant simulation code, and different techniques to optimize the injection efficiency are explored. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB118  
About • paper received ※ 19 May 2021       paper accepted ※ 31 May 2021       issue date ※ 12 August 2021  
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MOPAB119 Comparisons Between AT and Elegant Tracking 432
 
  • G. Penn, T. Hellert, M. Venturini
    LBNL, Berkeley, California, USA
  
  Funding: This work was supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DEAC02-05CH11231.
The simulation codes Elegant* and Accelerator Toolbox (AT)** are both in common use for the study of particle accelerators and light sources. They use different software platforms and have different capabilities, so there is a strong motivation to be able to switch from one version to another to achieve different goals. In addition, it is useful to directly compare results for benchmarking studies. We discuss differences in tracking methods and results for various elements, and explore the impact on simulations performed with lattices designed for the ALS-U. In addition to single-particle tracking, global properties such as chromaticity, dynamics aperture, momentum aperture and beam lifetime are also investigated. We have also developed scripts to translate AT lattices into elegant lattice files to facilitate comparisons.
* M. Borland, Advanced Photon Source LS-287, September 2000.
** A. Terebilo, Particle Accelerators Conference 2001, p. 3203. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB119  
About • paper received ※ 20 May 2021       paper accepted ※ 31 May 2021       issue date ※ 30 August 2021  
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MOPAB120 Update on Injector for the New Synchrotron Light Source in Thailand 435
 
  • T. Chanwattana, S. Chunjarean, N. Juntong, K. Kittimanapun, S. Klinkhieo, P. Sudmuang
    SLRI, Nakhon Ratchasima, Thailand
  • K. Manasatitpong
    Synchrotron Light Research Institute (SLRI), Muang District, Thailand
  
  Design of the new 3-GeV synchrotron light source in Thailand, Siam Photon Source II (SPS-II), has been updated. The SPS-II accelerator complex consists of a 150-MeV injector linac, a 3-GeV booster synchrotron and a 3-GeV storage ring. The RF system of both storage ring and booster is based on a frequency of 119 MHz. In this paper, design considerations and specifications of the SPS-II injector linac are presented. A study on the injector linac in multi-bunch mode (MBM) and single-bunch mode (SBM) was done to get appropriate parameters for top-up injection and different filling patterns in the storage ring.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB120  
About • paper received ※ 18 May 2021       paper accepted ※ 20 May 2021       issue date ※ 24 August 2021  
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MOPAB121 Progress Towards Soft X-Ray Beam Position Monitor Development 438
 
  • B. Podobedov, C. Eng, S. Hulbert, C. Mazzoli
    BNL, Upton, New York, USA
  • D. Donetski, K. Kucharczyk, J. Liu, R. Lutchman
    Stony Brook University, Stony Brook, New York, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
X-ray beam position monitors (BPMs) are instrumental for storage ring light sources, where they reliably provide positional measurements of high-power beams in hard X-ray beamlines. However, despite a growing need, coming especially from coherent soft X-ray beamlines, non-invasive soft X-ray BPMs have not been demonstrated yet. We are presently working on a funded R&D proposal to develop a non-invasive soft X-ray BPM with micron-scale resolution for high-power white beams. In our approach, multi-pixel GaAs detector arrays are placed into the beam halo and beam position is inferred from the pixel photocurrent levels. Presently, the first detector array prototypes have been manufactured and are being prepared for low-power beam tests. The mechanical design of a BPM test-stand, which will be installed in the 23-ID canted soft X-ray undulator beamline at NSLS-II, is well under way. In addition, we are developing new algorithms of beam position calculation which take full advantage of extended multi-pixel detector arrays. In this paper we will review our design choices and discuss recent progress. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB121  
About • paper received ※ 03 June 2021       paper accepted ※ 13 July 2021       issue date ※ 28 August 2021  
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MOPAB122 Present Status of HiSOR 442
 
  • M. Katoh
    UVSOR, Okazaki, Japan
  • K. Goto, M. Katoh, M. Shimada
    HSRC, Higashi-Hiroshima, Japan
  • H. Miyauchi
    KEK, Ibaraki, Japan
  
  HiSOR is a compact synchrotron light source of 700MeV. The circumference is 22m. The ring has two straight sections for undulators, which provide high brilliance VUV radiation. Two 180 bending magnets have 2.7 T field strength, which provide broadband radiation in VUV and soft X-ray range. The injector is a 150 MeV microtron. The beam injection is made twice a day with a 5 hour interval. Although the accelerators are being operated stably, the large emittance of 400nm makes it difficult to compete with high brilliance light sources of new generations. The compactness of the configuration makes it difficult to introduce new technologies. We have started seeking possible upgrades.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB122  
About • paper received ※ 18 May 2021       paper accepted ※ 20 May 2021       issue date ※ 30 August 2021  
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MOPAB123 Radiation Safety Considerations For The APS Upgrade Injector 445
 
  • K.C. Harkay, J.R. Calvey, S. Chitra, G.I. Fystro, M.J. Henry, E.E. Heyeck, B.J. Micklich, K.P. Wootton
    ANL, Lemont, Illinois, USA
  
  Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
The Advanced Photon Source Upgrade (APS-U) is a high-performance fourth-generation storage ring light source based on multibend achromat optics. As such, APS-U will require on-axis injection. The injectors will need to supply full-current bunch replacement in the ring; therefore, the injected bunch charge will be up to five times higher than what is typical for APS. A program was conducted to measure the radiation dose above the injector transport line to the APS storage ring for both normal operation conditions and controlled loss scenarios. Standard survey meters were used to record the dose. A review of the dose data identified opportunities to minimize the potential dose under normal APS-U high charge operation and fault conditions; these include improving the supplemental shielding and adding engineered controls. In addition, the dose data provide a benchmark for evaluating new radiation monitors for APS-U. 		 
poster icon Poster MOPAB123 [1.317 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB123  
About • paper received ※ 18 May 2021       paper accepted ※ 24 May 2021       issue date ※ 12 August 2021  
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MOPAB124 APS Booster Injection Horizontal Trajectory Control Upgrade 449
 
  • C. Yao, J.R. Calvey, G.I. Fystro, A.F. Pietryla, H. Shang
    ANL, Lemont, Illinois, USA
  
  Funding: * Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-ACO2-O6CH11357.
The APS booster is a 7-GeV electron synchrotron with a 0.5-second cycle. The booster runs a set of injection control programs that correct the beam trajectory in the horizontal and longitudinal planes, and the betatron tunes. Recently we developed a single-turn BPM controllaw program for horizontal trajectory control to replace the previous FFT based horizontal controllaw program. We present the system configuration and results. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB124  
About • paper received ※ 15 May 2021       paper accepted ※ 27 May 2021       issue date ※ 21 August 2021  
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MOPAB126 BESSY III & MLS II - Status of the Development of the New Photon Science Facility in Berlin 451
 
  • P. Goslawski, M. Abo-Bakr, F. Andreas, M. Arlandoo, J. Bengtsson, V. Dürr, K. Holldack, J.-G. Hwang, A. Jankowiak, B.C. Kuske, J. Li, A.N. Matveenko, T. Mertens, A. Meseck, E.C.M. Rial, M. Ries, M.K. Sauerborn, A. Schälicke, M. Scheer, P. Schnizer, L. Shi, J. Viefhaus
    HZB, Berlin, Germany
  • J. Lüning
    UPMC, Paris, France
  
  HZB operates and develops two synchrotron radiation sources at Berlin Adlershof. The larger one, BESSY II with an energy of 1.7 GeV and 240 m circumference is optimized for soft-X rays and in operation since 1999. The smaller one is the MLS (Metrology Light Source), owned by the Physikalische Technische Bundesanstalt (PTB) - Germany’s National Metrology Institute. It is designed to fulfill the special metrology needs of the PTB with an energy of 0.6 GeV and 48 m circumference, covering the spectral range from THz and IR to EUV/VUV. In 2020 a discussion process has been started to define the requirements for successors of BESSY II and MLS and to study the possibilities integrate them into a new photon science facility in Berlin Adlershof. Here, we give a status report and present a first envisaged parameter space to both machines (see also MOPAB262, MOPAB220, MOPAB048, MOPAB242).  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB126  
About • paper received ※ 18 May 2021       paper accepted ※ 24 June 2021       issue date ※ 18 August 2021  
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MOPAB127 Construction of an Impedance Model for Diamond-II 455
 
  • R.T. Fielder, T. Olsson
    DLS, Oxfordshire, United Kingdom
  
  Impedance models for accelerators have traditionally been presented in a static form, usually as tables or spreadsheets which must be read manually. As part of the Diamond-II upgrade work, we have developed an impedance model using a lattice structure. This allows more direct integration with simulation codes while keeping important information easily human readable. We present here a description of this implementation method, along with an overview of the Diamond-II impedance model derived from the latest engineering design.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB127  
About • paper received ※ 18 May 2021       paper accepted ※ 20 May 2021       issue date ※ 11 August 2021  
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MOPAB131 Synchrotron SOLEIL Upgrade Project 463
 
  • A. Nadji
    SOLEIL, Gif-sur-Yvette, France
  
  To remain competitive in the future, SOLEIL is also working on an upgrade project plan based on Multi-Bend Achromat (MBA) lattices. The Technical Design Report of the project is expected to start in early 2021 immediately after the completion of the Conceptual Design Report (CDR) phase. The achieved equilibrium emittance in the CDR reference lattice (80 pm-rad) is about 50 times smaller than that of the existing storage ring (4000 pm-rad). By operating on a linear coupling resonance, round beam sizes in Insertion Devices straight sections of less than 10 microns RMS in both planes can be produced. These performances rely on the use of a 10 mm inner diameter circular copper vacuum chamber with NEG-coating allowing reaching strong quadrupole gradients and very strong sextupole and octupole strengths. As all these technical challenges are pushing the engineering technology to the limits, they are being investigated through an intensive R&D program based on extensive numerical simulations, prototyping, and measurement with the beam. Extensive use of the pure permanent magnet technology beyond what has been done so far in the other similar projects is considered in this project.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB131  
About • paper received ※ 22 May 2021       paper accepted ※ 27 July 2021       issue date ※ 30 August 2021  
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TUPAB044 Preliminary Study of the on-Axis Swap-Out Injection Scheme for the Southern Advanced Photon Source 1447
 
  • Y. Han, X.H. Lu, Y. Zhao
    IHEP CSNS, Guangdong Province, People’s Republic of China
  • L. Huang, Y. Jiao, X. Liu, S. Wang
    IHEP, Beijing, People’s Republic of China
  
  The Southern Advanced Photon Source (SAPS) is a project under design, which aims at constructing a 4th generation storage ring with emittance below 100 pm.rad at the electron beam energy of around 3.5 GeV. The extremely low emittance will result in a very small dynamic aperture for the storage ring which makes it difficult to use the conventional off-axis accumulation injection. In this case, it is probably necessary to consider the transverse on-axis injection or the longitudinal injection. In this paper, the transverse on-axis swap-out injection scheme for the SAPS storage ring is presented. The preliminary parameters of the septum magnets and fast kickers are carefully evaluated.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB044  
About • paper received ※ 17 May 2021       paper accepted ※ 10 June 2021       issue date ※ 27 August 2021  
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TUPAB045 The Low Energy Injector Design for the Southern Advanced Photon Source 1450
 
  • Y. Han
    IHEP CSNS, Guangdong Province, People’s Republic of China
  • Y. Jiao, B. Li, X. Liu, S. Wang
    IHEP, Beijing, People’s Republic of China
  
  The Southern Advanced Photon Source (SAPS) is a project under design, which aims at constructing a 4th generation storage ring with emittance below 100 pm.rad at the electron beam energy of around 3.5 GeV. At present, two injector options are under consideration. One is a full energy booster plus a low energy injector, and another is a full energy linac injector. In this paper, a preliminary design of the low energy injector is presented, which consists of an DC thermionic electron gun, a bunching section and an accelerating section. The beam energy at the end of the injector is about 150 MeV.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB045  
About • paper received ※ 17 May 2021       paper accepted ※ 09 June 2021       issue date ※ 18 August 2021  
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TUPAB048 HMBA Optics Correction Experience at ESRF 1462
 
  • S.M. Liuzzo, N. Carmignani, L.R. Carver, L. Farvacque, T.P. Perron, P. Raimondi, S.M. White
    ESRF, Grenoble, France
  
  The ESRF-EBS storage ring, successfully commissioned in 2020, operates the HMBA lattice, first proposed in * and then adopted in several recent upgrade programs. The successful and timely commissioning of the storage is in large part due to the excellent optics control achieved over that period. Design performance were obtained with lower than predicted correction strengths, localized for the most part in the vicinity of sextupoles. This remarkable behavior is not only the result of the corrective actions taken during the commissioning but also of the extremely accurate conception and alignment of the machine. This report summarizes the steps that lead to the present performances and discusses their stability over time.
* J.Biasci et al. Synchrotron Radiation News27, 8 (2014), https://doi.org/10.1080/08940886.2014.970931. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB048  
About • paper received ※ 10 May 2021       paper accepted ※ 11 June 2021       issue date ※ 20 August 2021  
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TUPAB049 USSR HMBA Storage Ring Lattice Options 1466
 
  • S.M. Liuzzo, N. Carmignani, L.R. Carver, J. Chavanne, L. Hoummi, J. Jacob, T.P. Perron, R. Versteegen, S.M. White
    ESRF, Grenoble, France
  • I.A. Ashanin, V.S. Dyubkov, S.M. Polozov
    MEPhI, Moscow, Russia
  • I.A. Ashanin, V.S. Dyubkov, T. Kulevoy, S.M. Polozov
    NRC, Moscow, Russia
  • T. Kulevoy
    ITEP, Moscow, Russia
  
  Funding: European Union’s Horizon 2020 research and innovation program under grant #871072 Russian federation resolution #287
Several new accelerator facilities will be built in Russia in a few years from now. One of those facilities is a 6GeV storage ring (SR) light source (USSR - Ultimate Source of Synchrotron Radiation) to be built in Protvino, near Moscow. The Cremlin+ project aims to incorporate in this activity the best experience of European Accelerator Laboratories. The design of the optics for this SR is presented here in two declinations leading to 70 pm-rad equilibrium horizontal emittance. The first is a 40 cells lattice, the second is the same but includes high field Short Bending magnet sources in each cell. Optics and high order multipole optimizations are performed to obtain sufficient lifetime and dynamic aperture for a conservative off-axis injection. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB049  
About • paper received ※ 12 May 2021       paper accepted ※ 11 June 2021       issue date ※ 21 August 2021  
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TUPAB050 A Long Booster Option for the USSR 6 GeV Storage Ring 1470
 
  • S.M. Liuzzo, N. Carmignani, L.R. Carver, L. Hoummi, T.P. Perron, R. Versteegen, S.M. White
    ESRF, Grenoble, France
  • I.A. Ashanin, S.M. Polozov
    MEPhI, Moscow, Russia
  • I.A. Ashanin, T. Kulevoy, S.M. Polozov
    NRC, Moscow, Russia
  • T. Kulevoy
    ITEP, Moscow, Russia
  
  Funding: European Union’s Horizon 2020 research and innovation program under grant #871072 Russian federation resolution no. 287
The design of the optics of a full length 6 GeV booster for the USSR (Ultimate Source of Synchrotron Radiation) are presented. This option already followed with success by other laboratories, would allow to obtain a small emittance injected beam thus enabling smooth top-up operation. Details of the design inspired by the ESRF DBA lattice and the possible operating modes are described. The transfer lines booster to storage ring are also addressed in this paper. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB050  
About • paper received ※ 12 May 2021       paper accepted ※ 11 June 2021       issue date ※ 24 August 2021  
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TUPAB051 Elettra and Elettra 2.0 1474
 
  • E. Karantzoulis, A. Carniel, D. Castronovo, S. Di Mitri, B. Diviacco, S. Krecic
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  
  The status of the Italian 2.4/2.0 GeV third generation light source Elettra is presented together with the future upgrade concerning the new ultra-low emittance light source Elettra 2.0 that will provide ultra-high brilliance while the very short pulses feasibility study for time resolved experiments is in progress.  
poster icon Poster TUPAB051 [1.632 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB051  
About • paper received ※ 10 May 2021       paper accepted ※ 27 May 2021       issue date ※ 20 August 2021  
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TUPAB052 Current Study of Applying Machine Learning to Accelerator Physics at IHEP 1477
 
  • J. Wan, Y. Jiao
    IHEP, Beijing, People’s Republic of China
  
  Funding: National Natural Science Foundation of China(No.11922512), Youth Innovation Promotion Association of Chinese Academy of Sciences(No.Y201904) and National Key R&D Program of China(No.2016YFA0401900).
In recent years, machine learning (ML) has attracted increasing interest among the accelerator field. As a complex collection of multiple physical subsystems, the design and operation of an accelerator can be very nonlinear and complicated, while ML is taken as a powerful tool to solve such nonlinear and complicated problems. In this study, we report on several successful applications of ML to accelerator physics at IHEP. The nonlinear dynamics optimization of the High Energy Photon Source (HEPS) that is a 4th-generation light source is a challenging topic. In this optimization, we use a ML surrogate model to fast select the potentially competitive solutions for a multiobjective genetic algorithm that can significantly improve the convergence rate and the diversity among obtained solutions. Besides, we also tried to apply a generative adversarial net to solve one-to-many problems of longitudinal beam current profile shaping. Unlike most supervised machine learning methods than cannot learn one-to-many maps, the generative adversarial net-based method is able to predict multiple solutions instead of one for a 4-dipole chicane to realize several desired custom current profiles. 		 
poster icon Poster TUPAB052 [0.913 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB052  
About • paper received ※ 11 May 2021       paper accepted ※ 21 June 2021       issue date ※ 27 August 2021  
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TUPAB053 Design Progress of ALS-U 3rd-Harmonic Cavity 1481
 
  • T.H. Luo, K.M. Baptiste, S. De Santis, D. Li, J.W. Staples, M. Venturini
    LBNL, Berkeley, California, USA
  • H.Q. Feng
    TUB, Beijing, People’s Republic of China
  
  Funding: Director, Office of Science, Office of Basic Energy Sciences, and LDRD Program of Lawrence Berkeley National Laboratory, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231
A higher-harmonic rf cavity (HHC) system is required in the ALS-U storage ring to lengthen the bunches, reduce intrabeam-scattering effects, and improve Touschek beam lifetime. A 3rd harmonic, normal conducting, passive-cavity system has been chosen based on beam-dynamics requirements and cost considerations. We have explored two options for ALS-U 3HC system: a high-R/Q re-entrant cavity with waveguide HOM dampers, and a low-R/Q system with two elliptical cavities and HOM beam line absorbers. In this paper, we present the recent progress on the cavity design and related beam dynamics studies. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB053  
About • paper received ※ 19 May 2021       paper accepted ※ 11 June 2021       issue date ※ 14 August 2021  
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TUPAB054 CDR BASELINE LATTICE FOR THE UPGRADE OF SOLEIL 1485
 
  • A. Loulergue, D. Amorim, P. Brunelle, A. Gamelin, A. Nadji, L.S. Nadolski, R. Nagaoka, R. Ollier, M.-A. Tordeux
    SOLEIL, Gif-sur-Yvette, France
  
  Previous MBA studies converged toward a lattice composed of 20 7BA solution elaborated by adopting the sextupole pairing scheme with dispersion bumps originally developed at the ESRF-EBS. It provided a low natural horizontal emittance value of 70-80 pm-rad range at an energy of 2.75 GeV. Due to difficulties to accommodate such lattice geometry in the SOLEIL present tunnel as well as to preserve at best the beamline positioning, alternative lattice based on HOA (Higher-Order Achromat) type cell has been recently investigated. The HOA type cell being more modular and possibly exhibiting larger momentum acceptance as well as low emittances, a solution alternating 7BA and 4BA cells was then identified as the best to adapt the current beamline positioning. The SOLEIL CDR upgrade reference lattice is then composed of 20 HOA cells alternating 7BA and 4BA giving a natural horizontal emittance of 80 pm-rad. The linear and non-linear beam dynamic properties of the lattice along with the possibility of horizontal off-axis injection at full betatron coupling are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB054  
About • paper received ※ 21 May 2021       paper accepted ※ 02 July 2021       issue date ※ 10 August 2021  
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TUPAB058 Online Optimizations of Several Observable Parameters at the Advanced Photon Source 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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TUPAB059 Measurement of the Advanced Photon Source Lifetime at Different Level of Beta-Beating 1496
 
  • 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.
Linear optics correction of a particle accelerator may not be perfect due to the existence of different errors sources in response matrix measurements and optics correction process. Previous numerical simulation study has shown that the single particle beam dynamics performance may be highly correlated with the level of residual beta-beating. In this paper, the machine study results on beam lifetime of the APS storage ring is presented. The experiment is performed at different level of predefined beta-beating with negligible betatron tunes variations. As expected, the measured beam lifetime has an inverse correlation with the level of beta-beating. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB059  
About • paper received ※ 19 May 2021       paper accepted ※ 17 June 2021       issue date ※ 16 August 2021  
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TUPAB060 Machine Learning on Beam Lifetime and Top-Up Efficiency 1499
 
  • 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.
Both unsupervised and supervised machine learning techniques are employed for automatic clustering, modeling and prediction of Advanced Photon Source (APS) storage ring beam lifetime and top-up efficiency archived in operations. The naive Bayes classifier algorithm is developed and combined with k-means clustering to improve accuracy, where the unsupervised clustering of APS beam lifetime and top-up efficiency is consistent with either true label from data archive or Gaussian kernel density estimation. Artificial neural network algorithms have been developed, and employed for training and modelling the arbitrary relations of beam lifetime and top-up efficiency on many observable parameters. The predictions from artificial neural network reasonably agree with the APS operation data. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB060  
About • paper received ※ 22 May 2021       paper accepted ※ 21 June 2021       issue date ※ 22 August 2021  
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TUPAB061 Anomaly Detection by Principal Component Analysis and Autoencoder Approach 1502
 
  • 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.
Several different approach are employed to identify the abnormal events in some Advanced Photon Source (APS) operation archived dataset, where dimensionality reduction are performed by either principal component analysis or autoencoder artificial neural network. It is observed that the APS stored beam dump event, which is triggered by magnet power supply fault, may be predicted by analyzing the magnets capacitor temperatures dataset. There is reasonable agreement among two principal component analysis based approaches and the autoencoder artificial neural network approach, on predicting future overall system fault which may result in a stored beam dump in the APS storage ring. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB061  
About • paper received ※ 22 May 2021       paper accepted ※ 18 June 2021       issue date ※ 19 August 2021  
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TUPAB063 Study of PF-Ring Infrastructure Improvements Using Temperature Measurements in the Ring Tunnel 1508
 
  • N. Nakamura, K. Haga, T. Nogami, M. Tadano
    KEK, Ibaraki, Japan
  
  Temperature measurements have been performed in the PF-ring tunnel in order to understand the infrastructure performance and the temperature stability towards the PF upgrade project, where better beam stability will be required. Based on the temperature measurements, possible improvements of the PF-ring infrastructure such as an air-conditioning system have been studied to enhance the temperature stability in the PF-ring tunnel. In this paper, we present results of the temperature measurements in the PF-ring tunnel and a proposal of the PF-ring infrastructure improvements for the temperature stabilization.  
poster icon Poster TUPAB063 [6.169 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB063  
About • paper received ※ 18 May 2021       paper accepted ※ 26 May 2021       issue date ※ 16 August 2021  
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TUPAB065 Solaris Storage Ring Performance After 6 Years of Operation 1515
 
  • A.I. Wawrzyniak, A. Curcio, K. Gula, M.A. Knafel, G.W. Kowalski, A.M. Marendziak, R. Panaś, M. Waniczek, M. Wiśniowski
    NSRC SOLARIS, Kraków, Poland
  
  Solaris is a third generation light source operating since 2015 in Kraków, Poland. Between 2015 and 2018 the synchrotron as well as two beamlines were commissioned. During commissioning phases, the good performance of Solaris storage ring has been reached. The beam optics was brought close to the design one. Since October 2018 Solaris storage ring is in the user operation mode. Moreover, two other beamlines with the elliptically polarized undulators used as source were installed and are under commissioning now. In 2020 the total beam availability of 93% was reached with the average circulating current of 400 mA and the total lifetime of 15 h. Over last two years few improvements of the storage ring were done to optimize the storage ring performance. The Landau cavities were tuned to improve the Touschek lifetime and suppress the instabilities. Two diagnostics beamlines were installed and commissioned allowing for the beam sizes in three planes and emittance measurements. The storage ring optics was fine-tuned to increase the dynamic aperture.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB065  
About • paper received ※ 19 May 2021       paper accepted ※ 26 May 2021       issue date ※ 16 August 2021  
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TUPAB066 Status of the Short-Pulse Source at DELTA 1518
 
  • A. Held, B. Büsing, H. Kaiser, S. Khan, D. Krieg, A.R. Krishnan, C. Mai
    DELTA, Dortmund, Germany
  
  Funding: Work supported by BMBF (05K19PEB).
At the synchrotron light source DELTA operated by the TU Dortmund University, the short-pulse source employs the seeding scheme coherent harmonic generation (CHG) and provides ultrashort pulses in the vacuum ultraviolet and terahertz regime. Here, the interaction of laser pulses with the stored electron bunches result in a modulation of the longitudinal electron density which gives rise to coherent emission at harmonics of the laser wavelength. Recently, investigations of the influence of the Gouy phase shift at the focal point of the laser pulses on the laser-electron interaction have been performed. For the planned upgrade towards the more sophisticated seeding scheme echo-enabled harmonic generation (EEHG) featuring a twofold laser-electron interaction, simulations of the ideal parameters of the laser beams have been carried out. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB066  
About • paper received ※ 19 May 2021       paper accepted ※ 22 July 2021       issue date ※ 28 August 2021  
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THPAB065 Experimental Verification of the Source of Excessive Helical SCU Heat Load at APS 3904
 
  • V. Sajaev, J.C. Dooling, K.C. Harkay
    ANL, Lemont, Illinois, USA
  
  Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
Immediately after the installation of the Helical superconducting undulator (HSCU) in the APS storage ring, higher than expected heating was observed in the cryogenic cooling system. Steering the electron beam orbit in the upstream dipole reduced the amount of synchrotron radiation reaching into the HSCU and allowed the device to properly cool and operate. The simplest explanation of the excessive heat load was higher than expected heat transfer from the vacuum chamber to the magnet coils. However, modeling of the synchrotron radiation interaction with the HSCU vacuum chamber showed that Compton scattering could also result in synchrotron radiation penetrating the vacuum chamber and depositing energy directly into the HSCU coils**. In this paper, we present experimental evidence that the excessive heat load of the HSCU coils is not caused by the heat transfer from the vacuum chamber but resulted from the synchrotron radiation penetrating the vacuum chamber.
* M. Kasa et. al., Phys. Rev. AB, v. 23 050701 (2020)
** J. Dooling et. al., IPAC 2019 Proc., THPTS093 (2019) 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB065  
About • paper received ※ 12 May 2021       paper accepted ※ 02 September 2021       issue date ※ 16 August 2021  
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THPAB066 Ground Diffusion Measurement and Its Effect on APS-U Orbit Stability 3907
 
  • V. Sajaev
    ANL, Lemont, Illinois, USA
  
  Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
Spatial and temporal ground diffusion can be approximately described by the ATL law*,**. Ground diffusion can have an important effect on the long-term stability of the accelerator alignment. To estimate the possible consequences of the ground diffusion on the APS Upgrade performance, the ground diffusion constant of the existing APS tunnel was measured using historical data of the orbit correction effort and then used to estimate the ground diffusion effect on the orbit stability of the APS Upgrade. In this paper, we will describe the diffusion constant measurement and present the estimations of the expected APS-U alignment and orbit stability.
* B.A. Baklakov et. al., Technical Physics, v.38(10), pp.894-898(1993)
** V. Shiltsev, Physical Review Letters, 104(23), p.238501 (2010). 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB066  
About • paper received ※ 12 May 2021       paper accepted ※ 13 July 2021       issue date ※ 24 August 2021  
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THPAB067 Simulation of the APS-U Orbit Motion Due to RF Noise 3911
 
  • V. Sajaev
    ANL, Lemont, Illinois, USA
  
  Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
APS Upgrade storage ring will keep the same rf system that is presently used at APS. This rf system has amplitude and phase noise dominated by the lines at 60, 180, and 360 Hz. APS presently operates with synchrotron frequency close to 2 kHz, which is far away from the rf noise frequencies, and still the rf system noise contributes over 2 micrometers rms into the horizontal orbit noise due to beam energy variation. APS-U will operate with a bunch-lengthening cavity, which will lower the synchrotron frequency down to about 200 Hz. This could potentially lead to large orbit noise and other negative consequences due to energy variation caused by the rf system noise. In this paper, we will present simulations of the rf noise-induced orbit motion at APS and APS-U and define the rf amplitude and phase noise requirements that need to be achieved for APS-U operation. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB067  
About • paper received ※ 12 May 2021       paper accepted ※ 13 July 2021       issue date ※ 23 August 2021  
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THPAB073 Study of Seven-Bend-Achromat Lattice Option for Half 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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THPAB074 ESRF-EBS: Implementation, Performance and Restart of User Operation 3929
 
  • J.-L. Revol, P. Berkvens, J.-F. Bouteille, N. Carmignani, L.R. Carver, J.M. Chaize, J. Chavanne, F. Ewald, A. Franchi, L. Hardy, J. Jacob, L. Jolly, G. Le Bec, I. Leconte, S.M. Liuzzo, D. Martin, J. Pasquaud, T.P. Perron, Q. Qin, P. Raimondi, B. Roche, K.B. Scheidt, R. Versteegen, S.M. White
    ESRF, Grenoble, France
  
  The European Synchrotron Radiation Facility - Extremely Brilliant Source (ESRF-EBS) is a facility upgrade allowing its scientific users to take advantage of the first high-energy 4th generation light source. In December 2018, after 30 years of operation, the beam stopped for a 12-month shutdown to dismantle the old storage ring and to install the new X-ray source. In December 2019, the first beam was stored and accumulated in the storage ring, allowing the vacuum conditioning and tuning to be started. The beam was delivered to beamlines in March 2020 for their commissioning. On 25 August, the user programme was restarted with beam parameters very close to nominal values. In this report, the milestones and key aspects of the return to user-mode operation are presented and discussed.  
poster icon Poster THPAB074 [2.864 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB074  
About • paper received ※ 19 May 2021       paper accepted ※ 26 July 2021       issue date ※ 01 September 2021  
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THPAB078 SOLEIL Update Status 3945
 
  • L.S. Nadolski, G. Abeillé, Y.-M. Abiven, F. Bouvet, P. Brunelle, A. Buteau, N. Béchu, I. Chado, M.-E. Couprie, X. Delétoille, A. Gamelin, C. Herbeaux, N. Hubert, J.-F. Lamarre, V. Leroux, A. Lestrade, A. Loulergue, P. Marchand, O. Marcouillé, A. Nadji, R. Nagaoka, S. Pierre-Joseph Zéphir, F. Ribeiro, G. Schagene, K. Tavakoli, M.-A. Tordeux
    SOLEIL, Gif-sur-Yvette, France
  
  SOLEIL is both a synchrotron light source and a research laboratory at the cutting edge of experimental techniques dedicated to matter analysis down to the atomic scale, as well as a service platform open to all scientific and industrial communities. This French 2.75 GeV third generation synchrotron light source provides today extremely stable photon beams to 29 beamlines (BLs) complementary to ESRF. We report facility performance, ongoing projects and recent major achievements. Major R&D areas will also be discussed, and progress towards a lattice baseline for making SOLEIL a diffraction limited storage ring.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB078  
About • paper received ※ 22 May 2021       paper accepted ※ 12 July 2021       issue date ※ 22 August 2021  
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THPAB089 Lattice Design for a Future Plan of UVSOR Synchrotron 3970
 
  • E. Salehi, M. Katoh
    UVSOR, Okazaki, Japan
  • M. Katoh
    HSRC, Higashi-Hiroshima, Japan
  
  UVSOR is a 750 MeV synchrotron light source with a moderately small emittance of about 17nm. We surveyed the periodic solutions by drawing a tie diagram and mapped the emittance and the dynamic aperture on the tune diagram. The aim of this work is to search for a possible low emittance solution without a major change of the lattice. Although, we could not find a solution which has a drastically small emittance, we have found a few solutions which has a significantly smaller emittance than present value. They may be useful for some special low emittance operation modes dedicated to developments on new light sources technologies and their applications.  
poster icon Poster THPAB089 [1.592 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB089  
About • paper received ※ 19 May 2021       paper accepted ※ 27 July 2021       issue date ※ 16 August 2021  
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THPAB090 Progress with the Diamond-II Storage Ring Lattice 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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THPAB097 Towards Arbitrary Pulse Shapes in the Terahertz Domain 3977
 
  • C. Mai, B. Büsing, A. Held, S. Khan, D. Krieg
    DELTA, Dortmund, Germany
  
  Funding: Work supported by the BMBF (05K19PEC).
The TU Dortmund University operates the 1.5-GeV electron storage ring DELTA as a synchrotron light source in user operation and for accererator physics research. At a dedicated beamline, experiments with (sub-)THz radiation are carried out. Here, an interaction of short laser pulses with electron bunches is used to modulate the electron energy which causes the formation of a dip in the longitudinal electron density, giving rise to the coherent emission of radiation between 75 GHz and 6 THz. The standard mode of operation is the generation of broadband radiation. However, more sophisticated energy modulation schemes were implemented using a liquid-crystal phase modulator. Here, a modulation of the spectral phase of the laser is used to control the spectral shape of the THz pulses. The resulting THz spectra have a relative bandwidth of about 2 %. Measurement results from the different THz generation schemes are presented. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB097  
About • paper received ※ 18 May 2021       paper accepted ※ 12 July 2021       issue date ※ 24 August 2021  
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THPAB311 Using Linear Regression to Model the Parameters of the Flat Wires in TLS-EPU56 4399
 
  • S.J. Huang, Y.H. Chang, T.Y. Chung
    NSRRC, Hsinchu, Taiwan
  • Y.W. Chen
    Academia Sinica, Taipei, Taiwan
  
  Although a theoretical calculation might predict the set currents of the flat wires, which are used to compensate the deviation in the Betatron tune caused by the elliptically polarized undulator (EPU), those set currents must still be tuned in reality. To approach this reality, a strategy of Machine Learning was adopted, which included collecting real-condition data and using a linear-regression model to adjust the parameters of the flat wires. After training the model, the predictions in variables tune x, tune y and beam size x were compared with the required amount of correction of the EPU at various gaps and phases. To prove the feasibility of this method, a test was performed under the real conditions of accelerator Taiwan Light Source (TLS).  
poster icon Poster THPAB311 [1.226 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB311  
About • paper received ※ 13 May 2021       paper accepted ※ 28 June 2021       issue date ※ 30 August 2021  
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THPAB347 Status of Sirius Storage Ring RF System 4470
 
  • A.P.B. Lima, D. Daminelli, R.H.A. Farias, F.K.G. Hoshino, F.S. Oliveira, R.R.C. Santos, M.H. Wallner
    LNLS, Campinas, Brazil
  
  The design configuration of the Sirius Light Source RF System is based on two superconducting RF cavities and eight 60 kW solid state amplifiers operating at 500 MHz. The current configuration, based on a 7-cell room temperature cavity, was initially planned for commissioning and initial tests of the beamlines. However, it will have to remain in operation longer than planned. Sirius has been operating in decay mode for beamline tests with an initial current of 70 mA. We present an overview of the first-year operation of the RF system and the preparations for the installation of the two superconducting cavities, which is expected to take place in 2023.  
poster icon Poster THPAB347 [1.322 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB347  
About • paper received ※ 16 May 2021       paper accepted ※ 23 July 2021       issue date ※ 26 August 2021  
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FRXA01 Full Energy On-Demand Beam Injection from SACLA into the SPring-8 Storage Ring 4508
 
  • H. Maesaka, T. Fukui, T. Hara, T. Hiraiwa, T. Inagaki, E. Iwai, H. Tanaka, K. Togawa
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
  • H. Dewa, T. Fujita, K. Fukami, N. Hosoda, A. Kiyomichi, M. Masaki, S. Matsubara, T. Ohshima, M. Oishi, K. Soutome, S. Takano, T. Watanabe
    JASRI/SPring-8, Hyogo-ken, Japan
  • C. Kondo
    JASRI, Hyogo, Japan
  
  The beam injector for the SPring-8 storage ring (SR) was switched from the booster synchrotron to the SACLA linac, a driver for X-ray free-electron laser (XFEL). The low-emittance beam from SACLA (~100 pm rad, 8 GeV) is delivered to the SR through a 600m-long beam transport line. This low-emittance beam can be applied to the new low-emittance storage ring after the SPring-8 upgrade planed in the coming years. The shutdown of the booster synchrotron and 1-GeV linac saves energy consumption and operation cost. To provide the electron beam injected to the SR on demand for the top-up injection during the XFEL operation, the SACLA linac must be synchronized to the desired bucket of the SR, the beam energy and route must be switched shot-to-shot, and the XFEL performance must not be degraded. We developed a precise synchronization system, on-demand beam route and parameter switching system, a pulsed magnet for the switchyard, isolated bunch purification system, etc. In this presentation, we will show the design and performance of each component for the beam injection and the results from beam commissioning of the accelerator and transport line.  
slides icon Slides FRXA01 [3.446 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-FRXA01  
About • paper received ※ 19 May 2021       paper accepted ※ 01 July 2021       issue date ※ 31 August 2021  
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