Keyword: emittance
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MOYD3 EIC Transverse Emittance Growth Due to Crab Cavity RF Noise: Estimates and Mitigation cavity, feedback, simulation, target 6
 
  • T. Mastoridis, P. Fuller, P. Mahvi, Y. Matsumura
    CalPoly, San Luis Obispo, California, USA
  
  Funding: This work is partially supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics, under Award Number DE-SC-0019287.
The Electron-Ion Collider (EIC) requires crab cavities to compensate for a 25 mrad crossing angle and achieve maximum luminosity. The crab cavity Radio Frequency (RF) system will inject low levels of noise to the crabbing field, generating transverse emittance growth and potentially limiting luminosity lifetime. In this work, we estimate the transverse emittance growth rate as a function of the Crab Cavity RF noise and quantify RF noise specifications for reasonable performance. Finally, we evaluate the possible mitigation of the RF noise induced emittance growth via a dedicated feedback system. 		 
slides icon Slides MOYD3 [0.223 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOYD3  
About • Received ※ 28 July 2022 — Revised ※ 01 August 2022 — Accepted ※ 07 August 2022 — Issue date ※ 04 October 2022
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MOYD4 Model Parameters Determination in EIC Strong-Strong Simulation simulation, electron, proton, collider 9
 
  • D. Xu, C. Montag
    BNL, Upton, New York, USA
  • Y. Hao
    FRIB, East Lansing, Michigan, USA
  • Y. Luo
    Brookhaven National Laboratory (BNL), Electron-Ion Collider, Upton, New York, USA
  • J. Qiang
    LBNL, Berkeley, California, USA
  
  The ion beam is sensitive to numerical noise in the strong-strong simulation of the Electron-Ion Collider (EIC). This paper discusses the impact of model parameters — macro particles, transverse grids and longitudinal slices — on beam size evolution in PIC based strong-strong simulation. It will help us to understand the emittance growth in strong-strong simulation.  
slides icon Slides MOYD4 [0.849 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOYD4  
About • Received ※ 02 August 2022 — Revised ※ 03 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 11 August 2022
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MOZD5 ERL-Based Compact X-Ray FEL electron, FEL, optics, laser 37
 
  • F. Lin, V.S. Morozov
    ORNL RAD, Oak Ridge, Tennessee, USA
  • J. Guo, Y. Zhang
    JLab, Newport News, Virginia, USA
  
  Funding: Work supported by UT-Battelle, LLC, under contract DE-AC05-00OR22725, and by Jefferson Science Associates, LLC, under contract DE-AC05-06OR23177
We propose to develop an energy-recovery-linac (ERL)-based X-ray free-electron laser (XFEL). Taking advantage of the demonstrated high-efficiency energy recovery of the beam power in the ERL, the proposed concept offers the following benefits: i) recirculating the electron beam through high-gradient superconducting RF (SRF) cavities shortens the linac, ii) energy recovery in the SRF linac saves the klystron power and reduces the beam dump power, iii) the high average beam power produces a high average photon brightness. In addition, such a concept has the capability of delivering optimized high-brightness CW X-ray FEL performance at different energies with simultaneous multipole sources. In this paper, we will present the preliminary results on the study of feasibility, optics design and parameter optimization of such a device. 		 
slides icon Slides MOZD5 [2.870 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOZD5  
About • Received ※ 02 August 2022 — Revised ※ 04 August 2022 — Accepted ※ 04 August 2022 — Issue date ※ 11 September 2022
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MOZE3 Emittance Measurements and Simulations from an X-Band Short-Pulse Ultra-High Gradient Photoinjector gun, linac, simulation, laser 45
 
  • G. Chen, D.S. Doran, C.-J. Jing, S.Y. Kim, W. Liu, W. Liu, P. Piot, J.G. Power, C. Whiteford, E.E. Wisniewski
    ANL, Lemont, Illinois, USA
  • C.-J. Jing, E.W. Knight, S.V. Kuzikov
    Euclid TechLabs, Solon, Ohio, USA
  • C.-J. Jing
    Euclid Beamlabs, Bolingbrook, USA
  • X. Lu, P. Piot, W.H. Tan
    Northern Illinois University, DeKalb, Illinois, USA
  
  Funding: This work is supported by the U.S. DOE, under award No. DE-SC0018656 to NIU, DOE SBIR grant No. DE-SC0018709 to Euclid Techlabs LLC, and contract No. DE-AC02-06CH11357 with ANL.
A program is under way at the Argonne Wakefield Accelerator facility, in collaboration with the Euclid Techlabs and Northern Illinois University (NIU), to develop a GeV/m scale photocathode gun, with the ultimate goal of demonstrating a high-brightness photoinjector beamline. The novel X-band photoemission gun (Xgun) is powered by high-power, short RF pulses, 9-ns (FWHM), which, in turn, are generated by the AWA drive beam. In a previous proof-of-principle experiment, an unprecedented 400~MV/m gradient on the photocathode surface* was demonstrated. In the current version of the experiment, we added a linac to the beamline to increase the total energy and gain experience tuning the beamline. In this paper, we report on the very first result of emittance measurement as well as several other beam parameters. This preliminary investigation has identified several factors to be improved on in order to achieve one of the ultimate goals; low emittance.
* W. H. Tan et al., "Demonstration of sub-GV/m Accelerating Field in a Photoemission Electron Gun Powered by Nanosecond X-Band Radiofrequency Pulses", 2022. arXiv:2203.11598v1 		 
slides icon Slides MOZE3 [5.565 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOZE3  
About • Received ※ 03 August 2022 — Revised ※ 05 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 14 August 2022
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MOPA09 Design of a 4D Emittance Diagnostic for Low-Energy Ion Beams diagnostics, quadrupole, simulation, linac 67
 
  • T.R. Curtin, M.S. Curtin
    Ion Linac Systems, Inc., Albuquerque, USA
  
  Characterization of ion beams from an ion injector consisting of an electron-cyclotron-resonance (ECR) source in combination with a low-energy-beam-transport (LEBT) typically exhibits a complex four-dimensional transverse phase-space distribution. The importance of measuring the ion beam correlations following extraction and transport of the low-energy beam is critical to enabling optimization of beam transmission through downstream accelerating structures. A design for a transverse, four-dimensional emittance meter for low-energy protons from the Ion Linac Systems (ILS) ECR-LEBT ion injector is provided.  
poster icon Poster MOPA09 [0.479 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA09  
About • Received ※ 03 August 2022 — Revised ※ 27 September 2022 — Accepted ※ 05 December 2022 — Issue date ※ 05 December 2022
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MOPA36 Optimization of Superconducting Linac for Proton Improvement Plan-II (PIP-II) linac, cavity, quadrupole, solenoid 132
 
  • A. Pathak, E. Pozdeyev
    Fermilab, Batavia, Illinois, USA
  
  PIP-II is an essential upgrade of the Fermilab complex that will enable the world’s most intense high-energy beam of neutrinos for the international Deep Underground Neutrino Experiment at LBNF and support a broad physics program at Fermilab. Ultimately, the PIP-II superconducting linac will be capable of accelerating the H− CW beam to 800 MeV with an average power of 1.6 MW. To operate the linac with such high power, beam losses and beam emittance growth must be tightly controlled. In this paper, we present the results of global optimization of the Linac options towards a robust and efficient physics design for the superconducting section of the PIP-II linac. We also investigate the impact of the nonlinear field of the dipole correctors on the beam quality and derive the requirement on the field quality using statistical analysis. Finally, we assess the need to correct the quadrupole focusing produced by Half Wave, and Single Spoke accelerating cavities. We assess the feasibility of controlling the beam coupling in the machine by changing the polarity of the field of Linac focusing solenoids  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA36  
About • Received ※ 02 August 2022 — Revised ※ 04 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 01 October 2022
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MOPA50 Integrated Photonics Structure Cathodes for Longitudinally Shaped Bunch Trains wakefield, cathode, simulation, laser 160
 
  • S.J. Coleman, D.T. Abell, C.C. Hall
    RadiaSoft LLC, Boulder, Colorado, USA
  • R. Kapadia
    University of Southern California, Los Angeles, California, USA
  • S.S. Karkare
    Arizona State University, Tempe, USA
  • S.Y. Kim, P. Piot, J.F. Power
    ANL, Lemont, Illinois, USA
  
  Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award Number DOE DE-SC0021681
Compact, high-gradient structure wakefield accelerators can operate at improved efficiency using shaped electron beams, such as a high transformer ratio beam shape, to drive the wakes. These shapes have generally come from a photocathode gun followed by a transverse mask to imprint a desired shape on the transverse distribution, and then an emittance exchanger (EEX) to convert that transverse shape into a longitudinal distribution. This process discards some large fraction of the beam, limiting wall-plug efficiency as well as leaving a solid object in the path of the beam. In this paper, we present a proposed method of using integrated photonics structures to control the emission pattern on the cathode surface. This transverse pattern is then converted into a longitudinal pattern at the end of an EEX. This removes the need for the mask, preserving the total charge produced at the cathode surface. We present simulations of an experimental set-up to demonstrate this concept at the Argonne Wakefield Accelerator. 		 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA50  
About • Received ※ 03 August 2022 — Revised ※ 05 August 2022 — Accepted ※ 26 August 2022 — Issue date ※ 03 October 2022
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MOPA57 Online Models for X-Ray Beamlines optics, synchrotron, radiation, controls 170
 
  • B. Nash, D.T. Abell, M.V. Keilman, P. Moeller, I.V. Pogorelov
    RadiaSoft LLC, Boulder, Colorado, USA
  • Y. Du, A. Giles, J. Lynch, T. Morris, M.S. Rakitin, A. Walter
    BNL, Upton, New York, USA
  • N.B. Goldring
    STATE33 Inc., Portland, Oregon, USA
  
  Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Science, under Award Number DE-SC0020593
X-ray beamlines transport synchrotron radiation from the magnetic source to the sample at a synchrotron light source. Alignment of elements such as mirrors and gratings are often done manually and can be quite time consuming. The use of photon beam models during operations is not common in the same way that they are used to great benefit for particle beams in accelerators. Linear and non-linear optics including the effects of coherence may be computed from source properties and augmented with measurements. In collaboration with NSLS-II, we are developing software tools and methods to include the model of the x-ray beam as it passes on its way to the sample. We are integrating the Blue-Sky beamline control toolkit with the Sirepo interface to several x-ray optics codes. Further, we are developing a simplified linear optics approach based on a Gauss-Schell model and linear canonical transforms as well as developing Machine Learning models for use directly from diagnostics data. We present progress on applying these ideas on NSLS-II beamlines and give a future outlook on this rather large and open domain for technological development. 		 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA57  
About • Received ※ 27 July 2022 — Revised ※ 02 August 2022 — Accepted ※ 07 August 2022 — Issue date ※ 11 August 2022
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MOPA64 Circular Modes for Mitigating Space-Charge Effects and Enabling Flat Beams quadrupole, space-charge, optics, coupling 189
 
  • O. Gilanliogullari
    IIT, Chicago, Illinois, USA
  • B. Mustapha
    ANL, Lemont, Illinois, USA
  • P. Snopok
    Illinois Institute of Technology, Chicago, Illlinois, USA
  
  Funding: This work was supported by the U.S. Department of Energy, under Contract No. DE-AC02-06CH11357
Flat beams are preferred in high-intensity accelerators and high-energy colliders due to one of the transverse plane emittances being smaller, which enhances luminosity and beam brightness. However, flat beams are devastating at low energies due to space charge forces which are significantly enhanced in one plane. The same is true, although to a lesser degree, for non-symmetric elliptical beams. In order to mitigate this effect, circular mode beam optics can be used. In this paper, we show that circular mode beams dilute space charge effects at lower energies, and can be transformed to flat beams later on. 		 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA64  
About • Received ※ 09 August 2022 — Revised ※ 11 August 2022 — Accepted ※ 12 August 2022 — Issue date ※ 23 August 2022
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MOPA79 Studying the Emission Characteristics of Field Emission Cathodes with Various Geometries cathode, experiment, ECR, simulation 226
 
  • M.R. Howard, S.M. Lidia
    FRIB, East Lansing, Michigan, USA
  • J.E. Coleman
    LANL, Los Alamos, New Mexico, USA
  
  Funding: Work supported by the NNSA of US DOE under contract 89233218CNA000001 and partially supported by the US DOE under Cooperative Agreement award number DE-SC0018362 and Michigan State University.
The cathode test stand (CTS) at LANL is designed to hold off voltages of up to 500kV and can supply pulse durations up to 2.6 μs. Using this test stand, we are able to test both field emission and photocathodes with different geometries and materials at various pulse lengths and PFN voltages. Currently, the test stand is used to evaluate field emission using a velvet cathode over various pulse lengths. The CTS employs various diagnostic tools, including E-dots, B-dots, and a scintillator coupled with a pepperpot mask in order to measure the extracted voltage, current, beam distribution, and transverse emittance. Xenos [1] has been used to create and simulate diode geometries that permits study to optimize various beam parameters. These geometries include changing the size and recess of the cathode as well as implementing a Pierce geometry. Here, we will discuss comparisons for various simulated cathodes and how changes in geometry impact given beam parameters.
[1] See https://www.fieldp.com/xenos.html for information about the Xenos software. 		 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA79  
About • Received ※ 02 August 2022 — Revised ※ 10 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 30 August 2022
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MOPA82 Space Charge Driven Third Order Resonance at AGS Injection resonance, experiment, space-charge, injection 236
 
  • M.A. Balcewicz, Y. Hao
    FRIB, East Lansing, Michigan, USA
  • Y. Hao, H. Huang, C. Liu, K. Zeno
    BNL, Upton, New York, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy
Resonance line crossings at significant space charge tune shifts can exhibit various phenomena due to periodic resonance crossing from synchrotron motion* and manifests as halo generation and bunch shortening along with the more mundane emittance growth and beam loss. An injection experiment is conducted at the AGS using the fast wall current monitor and electron collecting Ionization Profile Monitor (eIPM) to probe third order resonances to better characterize the resonance crossing over a 4 ms time scale. This experiment shows some agreement with previous experiments, save for lack of bunch shortening, possibly due to relative resonance strength.
* G. Franchetti et al. PRSTAB 13, 114203. 2010 		 
poster icon Poster MOPA82 [1.924 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA82  
About • Received ※ 02 August 2022 — Revised ※ 09 August 2022 — Accepted ※ 19 August 2022 — Issue date ※ 24 August 2022
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MOPA90 Relating Initial Distribution to Beam Loss on the Front End of a Heavy-Ion Linac Using Machine Learning network, simulation, LEBT, controls 263
 
  • A.D. Tran, Y. Hao
    FRIB, East Lansing, Michigan, USA
  • J.L. Martinez Marin, B. Mustapha
    ANL, Lemont, Illinois, USA
  
  Funding: This work was supported by a sub-reward from Argonne National Laboratory and supported by the U.S. Department of Energy, under Contract No. DE-AC02-06CH11357.
This work demonstrates using a Neural Network and a Gaussian Process to model the ATLAS front-end. Various neural network architectures were created and trained on the machine settings and outputs to model the phase space projections. The model was then trained on a dataset, with non-linear distortion, to gauge the transferability of the model from simulation to machine. 		 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA90  
About • Received ※ 02 August 2022 — Revised ※ 05 August 2022 — Accepted ※ 06 August 2022 — Issue date ※ 11 September 2022
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TUYD3 The Quest for the Perfect Cathode cathode, gun, electron, photon 281
 
  • J.W. Lewellen, J. Smedley, T. Vecchione
    SLAC, Menlo Park, California, USA
  • D. Filippetto
    LBNL, Berkeley, California, USA
  • S.S. Karkare
    Arizona State University, Tempe, USA
  • J.M. Maxson
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • P. Musumeci
    UCLA, Los Angeles, California, USA
  
  Funding: U.S. Department of Energy.
The next generation of free electron lasers will be the first to see the performance of the laser strongly dependent on the materials properties of the photocathode. A new injector proposed for the LCLS-II HE is an example of this revolution, with the goal of increasing the photon energy achievable by LCLS-II to over 20 keV. We must now ask, what is the optimal cathode, temperature, and laser combination to enable this injector? There are many competing requirements. The cathode must be robust enough to operate in a superconducting injector, and must not cause contamination of the injector. It must achieve sufficient charge at high repetition rate, while minimizing the emittance. The wavelength chosen must minimize mean transverse energy while maintaining tolerable levels of multi-photon emission. The cathode must be capable of operating at high (~30 MV/m) gradient, which puts limits on both surface roughness and field emission. This presentation will discuss the trade space for such a cathode/laser combination, and detail a new collaborative program among a variety of institutions to investigate it. 		 
slides icon Slides TUYD3 [1.632 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUYD3  
About • Received ※ 02 August 2022 — Revised ※ 04 August 2022 — Accepted ※ 14 August 2022 — Issue date ※ 26 September 2022
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TUYD4 Towards High Brightness from Plasmon-Enhanced Photoemitters cathode, electron, laser, interface 285
 
  • C.M. Pierce, I.V. Bazarov, J.M. Maxson
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • D.B. Durham, D. Filippetto, F. Riminucci
    LBNL, Berkeley, USA
  • A.H. Kachwala, S.S. Karkare
    Arizona State University, Tempe, USA
  • A. Minor
    UC Berkeley, Berkeley, California, USA
  
  Funding: This work is supported by DOE BES Contract No. DE-AC02-05CH11231. C.P. acknowledges NSF Award PHY-1549132 (CBB) and the US DOE SCGSR program. DD was supported by NSF Grant No. DMR-1548924 (STROBE).
Plasmonic cathodes, whose nanoscale features may locally enhance optical energy from the driving laser trapped at the vacuum interface, have emerged as a promising technology for improving the brightness of metal cathodes. A six orders of magnitude improvement [1] in the non-linear yield of metals has been experimentally demonstrated through this type of nanopatterning. Further, nanoscale lens structures may focus light below its free-space wavelength offering multiphoton photoemission from a region near 10 times smaller [2] than that achievable in typical photoinjectors. In this proceeding, we report on our efforts to characterize the brightness of two plasmonic cathode concepts: a spiral lens and a nanogroove array. We demonstrate an ability to engineer and fabricate nanoscale patterned cathodes by comparing their optical properties with those computed with a finite difference time domain (FDTD) code. The emittance and nonlinear yield of the cathodes are measured under ultrafast laser irradiation. Finally, prospects of this technology for the control and acceleration of charged particle beams are discussed.
[1] Polyakov, A., et al. (2013). Physical Review Letters, 110(7), 076802.
[2] Durham, D. B., et al. (2019). Physical Review Applied, 12(5), 054057.
 		 
slides icon Slides TUYD4 [7.160 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUYD4  
About • Received ※ 05 August 2022 — Revised ※ 08 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 13 September 2022
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TUZD5 Experience and Challenges with Electron Cooling of Colliding Ion Beams in RHIC electron, operation, collider, cathode 325
 
  • A.V. Fedotov, X. Gu, D. Kayran, J. Kewisch, S. Seletskiy
    BNL, Upton, New York, USA
  
  Funding: Work supported by the U.S. Department of Energy.
Electron cooling of ion beams employing rf-accelerated electron bunches was successfully used for the RHIC physics program in 2020 and 2021 and was essential in achieving the required luminosity goals. This presentation will summarize experience and challenges with electron cooling of colliding ion beams in RHIC. We also outline ongoing studies using rf-based electron cooler LEReC. 		 
slides icon Slides TUZD5 [1.373 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUZD5  
About • Received ※ 02 August 2022 — Accepted ※ 04 August 2022 — Issue date ※ 14 September 2022  
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TUZE4 Particle-in-Cell Simulations of High Current Density Electron Beams in the Scorpius Linear Induction Accelerator simulation, electron, plasma, induction 339
 
  • S.E. Clark, Y.-J. Chen, J. Ellsworth, A.T. Fetterman, C.N. Melton, W.D. Stem
    LLNL, Livermore, USA
  
  Funding: This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
Particle-in-cell (PIC) simulations of a high current density (I > 1 kA), and highly relativistic electron beam (E ~ 2-20 MeV) in the Scorpius Linear Induction Accelerator (LIA) are presented. The simulation set consists of a 3D electrostatic/magnetostatic simulation coupled to a 2D XY slice solver that propagates the beam through the proposed accelerator lattice for Scorpius, a next-generation flash X-ray radiography source. These simulations focus on the growth of azimuthal modes in the beam (e.g. Diocotron instability) that arise when physical ring distributions manifest in the beam either due to electron optics or solenoidal focusing and transport. The saturation mechanism appears to lead to the generation of halo particles and conversion down to lower mode numbers as the width of the ring distribution increases. The mode growth and saturation can contribute to the generation of hot spots on the target as well possible azimuthal asymmetries in the radiograph. Simulation results are compared to linear theory and tuning parameters are investigated to mitigate the growth of azimuthal modes in the Scorpius electron beam.
* LLNL-ABS-830595, Approved for public release. Distribution Unlimited. 		 
slides icon Slides TUZE4 [4.305 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUZE4  
About • Received ※ 02 August 2022 — Revised ※ 05 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 21 September 2022
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TUZE5 Studies of Ion Beam Heating by Electron Beams electron, experiment, gun, solenoid 343
 
  • S. Seletskiy, A.V. Fedotov, D. Kayran
    BNL, Upton, New York, USA
  
  Presence of an electron beam created by either electron coolers or electron lenses in an ion storage ring is associated with an unwanted emittance growth (heating) of the ion bunches. In this paper we report experimental studies of the electron-ion heating in the Low Energy RHIC electron Cooler (LEReC).  
slides icon Slides TUZE5 [1.368 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUZE5  
About • Received ※ 01 August 2022 — Revised ※ 09 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 17 September 2022
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TUZE6 Studies of Ion Instability Using a Gas Injection System simulation, feedback, injection, experiment 347
 
  • J.R. Calvey, M. Borland, L. Emery, P.S. Kallakuri
    ANL, Lemont, Illinois, USA
  
  Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
Ion trapping occurs when a negatively charged beam ionizes residual gas inside an accelerator vacuum chamber, and the resulting ions become trapped in the beam potential. Trapped ions can cause a variety of undesirable effects, including coherent instability and incoherent emittance growth. Because of the challenging emittance and stability requirements of next generation light sources, ion trapping is a serious concern. To study this effect at the present APS, a gas injection system was designed and installed at two different locations in the ring. The system creates a controlled and localized pressure bump of nitrogen gas, so the resulting ion instability can be studied. Measurements were taken under a wide variety of beam conditions, using a spectrum analyzer, pinhole camera, and bunch-by-bunch feedback system. The feedback system was also used to perform grow-damp measurements, allowing us to measure the growth rate of individual unstable modes. This paper will present some of the results of these experiments. Simulations using the IONEFFECTS element in the particle tracking code elegant will also be presented. 		 
slides icon Slides TUZE6 [2.425 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUZE6  
About • Received ※ 03 August 2022 — Revised ※ 07 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 24 August 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPA18 Promise and Challenges of a Method for 5x5 Sigma Matrix Measurement in a Transport Line quadrupole, booster, extraction, simulation 382
 
  • M. Borland, V. Sajaev, K.P. Wootton
    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 (APS) is upgrading the storage ring to a design that requires on-axis injection. Matching between the incoming beam and the ring is important to ensure high injection efficiency. Toward this end, we have developed and tested a method for measuring all σ matrix elements except those related to the time coordinate. We report on challenges inherent in this technique, based on simulation and real-world trials. 		 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA18  
About • Received ※ 29 July 2022 — Accepted ※ 05 August 2022 — Issue date ※ 29 September 2022  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPA48 Effect of Lattice Misalignments on Beam Dynamics in LANSCE Linear Accelerator alignment, linac, lattice, simulation 455
 
  • Y.K. Batygin, S.S. Kurennoy
    LANL, Los Alamos, New Mexico, USA
  
  Funding: Work supported by US DOE under contract 89233218CNA000001
Accelerator channel misalignments can significantly affect beam parameters in long linear accelerators. Measurements of misalignments of the LANSCE linac lattice elements was performed by the Mechanical Design Engineering Group of the Los Alamos Accelerator Operations and Technology Division. In order to determine effect of misalignment on beam parameters in LANSCE linac, the start-to-end simulations of LANSCE accelerator were performed using Beampath and CST codes including measured displacements of quadrupoles and accelerating tanks. Simulations were done for both H+ and H− beams with various beam flavors. Effect of misalignments was compared with those due to beam space charge and distortion of RF field along the channel. Paper presents results of simulation and comparison with experimental data of beam emittance growth along the machine. 		 
poster icon Poster TUPA48 [1.547 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA48  
About • Received ※ 23 July 2022 — Revised ※ 28 July 2022 — Accepted ※ 04 August 2022 — Issue date ※ 14 August 2022
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TUPA57 Electromagnetic and Beam Dynamics Modeling of the LANSCE Coupled-Cavity Linac cavity, linac, simulation, quadrupole 472
 
  • S.S. Kurennoy, Y.K. Batygin, D.V. Gorelov
    LANL, Los Alamos, New Mexico, USA
  
  The 800-MeV proton linac at LANSCE consists of a drift-tube linac, which brings the beam to 100 MeV, followed by a coupled-cavity linac (CCL) consisting of 44 modules. Each CCL module contains multiple tanks, and it is fed by a single 805-MHz klystron. CCL tanks are multi-cell blocks of identical re-entrant side-coupled cavities, which are followed by drifts with magnetic quadrupole doublets. Bridge couplers - special cavities displaced from the beam axis - electromagnetically couple CCL tanks over such drifts. We have developed 3D CST models of CCL tanks. Their electromagnetic analysis is performed using MicroWave Studio. Beam dynamics is modeled with Particle Studio for bunch trains with realistic beam distributions using the CST calculated RF fields and quadrupole magnetic fields to determine the output beam parameters. Beam dynamics results are crosschecked with other multi-particle codes.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA57  
About • Received ※ 15 July 2022 — Revised ※ 01 August 2022 — Accepted ※ 08 August 2022 — Issue date ※ 19 August 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPA72 Comparison Study on First Bunch Compressor Schemes by Conventional and Double C-Chicane for MaRIE XFEL dipole, electron, FEL, radiation 496
 
  • H. Xu, P.M. Anisimov, L.D. Duffy, Q.R. Marksteiner
    LANL, Los Alamos, New Mexico, USA
  
  Funding: Laboratory Directed Research and Development program of Los Alamos National Laboratory, project number 20200287ER.
We report our comparison study on the first stage electron bunch compression schemes at 750 MeV using a conventional and a double C-chicane for the X-ray free electron laser (XFEL) under development for the Matter-Radiation Interactions in Extremes (MaRIE) initiative at Los Alamos National Laboratory. Compared to the performance of the conventional C-chicane bunch compressor, the double C-chicane scheme exhibits the capability of utilizing the transverse momentum shift induced by the coherent synchrotron radiation in the second C-chicane to compensate that generated in the first C-chicane, resulting in a compressed electron bunch with minimized transverse momentum shift along the beam. It is also found that the double C-chicane scheme can be designed to significantly better preserve the beam emittance in the course of the bunch compression. This is particularly beneficial for the MaRIE XFEL whose lasing performance critically depends on the preservation of the ultralow beam emittance. 		 
poster icon Poster TUPA72 [1.339 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA72  
About • Received ※ 01 August 2022 — Accepted ※ 06 August 2022 — Issue date ※ 15 August 2022  
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TUPA86 Simulations of Nanoblade Cathode Emissions with Image Charge Trapping for Yield and Brightness Analyses electron, brightness, laser, scattering 535
 
  • J.I. Mann, G.E. Lawler, J.B. Rosenzweig, B. Wang
    UCLA, Los Angeles, California, USA
  • T. Arias, J.K. Nangoi
    Cornell University, Ithaca, New York, USA
  • S.S. Karkare
    Arizona State University, Tempe, USA
  
  Funding: National Science Foundation Grant No. PHY-1549132
Laser-induced field emission from nanostructures as a means to create high brightness electron beams has been a continually growing topic of study. Experiments using nanoblade emitters have achieved peak fields upwards of 40 GV/m according to semi-classical analyses, begging further theoretical investigation. A recent paper has provided analytical reductions of the common semi-infinite Jellium system for pulsed incident lasers. We utilize these results to further understand the physics underlying electron rescattering-type emissions. We numerically evaluate this analytical solution to efficiently produce spectra and yield curves. The effect of space-charge trapping at emission may be simply included by directly modifying these spectra. Additionally, we use a self-consistent 1-D time-dependent Schrödinger equation with an image charge potential to study the same system as a more exact, but computationally costly, approach. With these results we may finally investigate the mean transverse energy and beam brightness at the cathode in these extreme regimes. 		 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA86  
About • Received ※ 02 August 2022 — Revised ※ 08 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 03 September 2022
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WEXD2 Storage Ring Tracking Using Generalized Gradient Representations of Full Magnetic Field Maps lattice, dipole, quadrupole, sextupole 542
 
  • R.R. Lindberg, M. Borland
    ANL, Lemont, Illinois, USA
  
  Funding: This work was supported by U.S. Dept. of Energy Office of Sciences under Contract No. DE-AC02-06CH11357.
We have developed a set of tools to simulate particle dynamics in the full magnetic field using the generalized gradients representation. Generalized gradients provide accurate and analytic representations of the magnetic field that allow for symplectic tracking [1]. We describe the tools that convert magnetic field data into generalized gradients representations suitable for tracking in Elegant, and discuss recent results based upon tracking with the full field representations for all magnets in the APS-U storage ring.
[1] A. Dragt. Lie Methods for Nonlinear Dynamics with Applications to Accelerator Physics. University of Maryland (2019). 		 
slides icon Slides WEXD2 [3.841 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEXD2  
About • Received ※ 16 July 2022 — Accepted ※ 29 July 2022 — Issue date ※ 04 August 2022  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEXD3 Map Tracking Including the Effect of Stochastic Radiation radiation, lattice, damping, photon 548
 
  • D. Sagan, G.H. Hoffstaetter
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • E. Forest
    KEK, Ibaraki, Japan
  
  Funding: Department of Energy
Using transfer maps to simulate charged particle motion in accelerators is advantageous since it is much faster than tracking step-by-step. One challenge to using transfer maps is to properly include radiation effects. The effect of radiation can be divided into deterministic and stochastic parts. While computation of the deterministic effect has been previously reported, handling of the stochastic part has not. In this paper, an algorithm for including the stochastic effect is presented including taking into account the finite opening angle of the emitted photons. A comparison demonstrates the utility of this approach. Generating maps which include radiation has been implemented in the PTC software library which is interfaced to the Bmad toolkit. 		 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEXD3  
About • Received ※ 06 August 2022 — Revised ※ 16 August 2022 — Accepted ※ 21 August 2022 — Issue date ※ 24 August 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEXD5 Benchmarking Simulation for AWA Drive Linac and Emittance Exchange Beamline Using OPAL, GPT, and Impact-T simulation, linac, gun, solenoid 552
 
  • S.Y. Kim, G. Chen, D.S. Doran, G. Ha, W. Liu, J.G. Power, E.E. Wisniewski
    ANL, Lemont, Illinois, USA
  • E.A. Frame, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
  
  At the Argonne Wakefield Accelerator (AWA) facility, particle-tracking simulations have been critical to guiding beam-dynamic experiments, e.g., for various beam manipulations using an available emittance-exchange beamline (EEX). The unique beamline available at AWA provide a test case to perform in-depth comparison between different particle-tracking programs including collective effects such as space-charge force and coherent synchrotron radiation. In this study, using AWA electron injector and emittance exchange beamline, we compare the simulations results obtained by GPT, OPAL, and Impact-T beam-dynamics programs. We will specifically report on convergence test as a function of parameters that controls the underlying algorithms.  
slides icon Slides WEXD5 [1.847 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEXD5  
About • Received ※ 03 August 2022 — Revised ※ 06 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 22 August 2022
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WEYD3 Positron Acceleration in Linear, Moderately Non-Linear and Non-Linear Plasma Wakefields positron, plasma, collider, electron 560
 
  • G.J. Cao, E. Adli
    University of Oslo, Oslo, Norway
  • S. Corde
    LOA, Palaiseau, France
  • S.J. Gessner
    SLAC, Menlo Park, California, USA
  
  Accelerating particles to high energies with high efficiency and beam quality is crucial in developing accelerator technologies. The plasma acceleration technique, providing unprecedented high gradients, is considered as a promising future technology. While important progress has been made in plasma-based electron acceleration in recent years, identifying a reliable acceleration technique for the positron counterpart would pave the way to a linear e+e− collider for high-energy physics applications. In this work, we show further studies of positron beam quality in moderately non-linear (MNL)* plasma wakefields. With a positron bunch of initial energy 1 GeV, emittance preservation can be achieved in optimised scenarios at 2.38 mm’mrad. In parallel, asymmetric beam collisions at the interaction point (IP) are studied to evaluate the current luminosity reach and provide insight to improvements required for positron acceleration in plasma. It is necessary to scale down the emittance of the positron bunch. In the MNL regime, a positron beam with 238 ’m’mrad level emittance implies compromise in charge or necessity for ultra-short bunches.
* "Efficiency and beam quality for positron acceleration in loaded plasma wakefields",C. S. Hue, G. J. Cao, et.al Phys. Rev. Research 3, 043063 		 
slides icon Slides WEYD3 [3.635 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEYD3  
About • Received ※ 01 August 2022 — Revised ※ 09 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 24 August 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEYE5 Model/Measurement Comparison of the Transverse Phase Space Distribution of an RFQ-Generated Bunch at the SNS BTF rfq, simulation, MEBT, space-charge 584
 
  • K.J. Ruisard, A.V. Aleksandrov, S.M. Cousineau, A.M. Hoover, A.P. Zhukov
    ORNL, Oak Ridge, Tennessee, USA
  
  Funding: This work is supported by US DOE, Office of Science, HEP. This manuscript is authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with US DOE.
The research program at the SNS Beam Test Facility is focused on resolving observed model/measurement discrepancies that preclude accurate loss prediction in high-power linacs. The current program of study is focused on deploying direct 6D measurements to reconstruct a realistic model of the initial beam distribution at the RFQ output. This detailed characterization also provides an opportunity for benchmark of RFQ simulations. Here we compare PARMTEQ predictions against 5D-resolved (x, x’, y, y’, dE) phase space measurements of the BTF H− bunch, focusing on the transverse distribution. This work is an extension of [1], which focused on the longitudinal phase space.
[1] K. Ruisard et al., doi: 10.1103/PhysRevAccelBeams.23.124201.
[2] A. Hoover et al., "Measurements of the Five-Dimensional Phase Space Distribution of a High-Intensity Ion Beam," these proceedings. 		 
slides icon Slides WEYE5 [2.646 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEYE5  
About • Received ※ 03 August 2022 — Revised ※ 11 August 2022 — Accepted ※ 13 August 2022 — Issue date ※ 04 October 2022
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WEPA01 Beam Dynamics Optimization of a Low Emittance Photoinjector Without Buncher Cavities cavity, electron, cathode, gun 615
 
  • J. Qiang
    LBNL, Berkeley, California, USA
  • F. Ji, T.O. Raubenheimer
    SLAC, Menlo Park, California, USA
  
  The photoinjector plays an important role in generating high brightness low emittance electron beam for x-ray free electron laser applications. In this paper, we report on beam dynamics optimization study of a low emittance photoinjector based on a proposed superconducting gun without including any buncher cavities. Multi-objective optimization with self-consistent beam dynamics simulations was employed to attain the optimal Pareto front.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA01  
About • Received ※ 02 August 2022 — Revised ※ 05 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 11 September 2022
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WEPA02 Beam Dynamics Studies on a Low Emittance Injector for LCLS-II-HE cathode, gun, solenoid, cavity 619
 
  • F. Ji, C. Adolphsen, R. Coy, L. Ge, C.E. Mayes, T.O. Raubenheimer, L. Xiao
    SLAC, Menlo Park, California, USA
  • J. Qiang
    LBNL, Berkeley, California, USA
  
  The SLAC High Energy upgrade of LCLS-II (LCLS-II-HE) will double the beam energy to 8 GeV, increasing the XFEL photon energy reach to about 13 keV. The energy reach can be extended to 20 keV if the beam emittance can be halved, which requires a higher gradient electron gun with a lower intrinsic emittance photocathode. To this end, the Low Emittance Injector (LEI) will be built that will run parallel to the existing LCLS-II Injector. The LEI design will be based on a state-of-the-art SRF gun with a 30 MV/m cathode gradient. The main goal is to produce transverse beam emittances of 0.1 mm-mrad for 100 pC bunch charges. This paper describes the beam dynamics studies on the design of the LEI including the simulations and multi-objective genetic algorithm (MOGA) optimizations. Performance with different injector layouts, cathode gradients, bunch charges and cathode mean transverse energies (MTEs) will be presented.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA02  
About • Received ※ 02 August 2022 — Revised ※ 11 August 2022 — Accepted ※ 12 August 2022 — Issue date ※ 17 August 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPA04 Simulating Two Dimensional Transient Coherent Synchrotron Radiation in Julia radiation, synchrotron-radiation, GPU, synchrotron 627
 
  • W. Lou, Y. Cai, C.E. Mayes
    SLAC, Menlo Park, California, USA
  
  Coherent Synchrotron Radiation (CSR) in bending magnets poses a limit for electron beams to reach high brightness in novel accelerators. While the longitudinal wakefield has been well studied in the one-dimensional CSR theory and implemented in various simulation codes, transverse wakefields have received less attention. Following the recently developed two and three-dimensional CSR theory, we developed software packages in Python and Julia to simulate the 2D CSR effects. The Python packages, PyCSR2D and PyCSR3D, utilize parallel processing in CPU to compute the steady-state CSR wakes. The Julia package, CSR2D.jl, additionally computes the 2D transient CSR wakes with GPU compatibility. We applied these codes to simulate the 2D CSR effects in the LCLS-II and FACET-II particle accelerators at the SLAC National Accelerator Laboratory.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA04  
About • Received ※ 03 August 2022 — Revised ※ 08 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 18 August 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPA24 pyJSPEC - A Python Module for IBS and Electron Cooling Simulation electron, simulation, scattering, experiment 672
 
  • H. Zhang, S.V. Benson, M.W. Bruker, Y. Zhang
    JLab, Newport News, Virginia, USA
  
  Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177.
The intrabeam scattering is an important collective effect that can deteriorate the property of a high-intensity beam and electron cooling is a method to mitigate the IBS effect. JSPEC (JLab Simulation Package on Electron Cooling) is an open-source C++ program developed at Jefferson Lab, which simulates the evolution of the ion beam under the IBS and/or the electron cooling effect. The Python wrapper of the C++ code, pyJSPEC, for Python 3.x environment has been recently developed and released. It allows the users to run JSPEC simulations in a Python environment. It also makes it possible for JSPEC to collaborate with other accelerator and beam modeling programs as well as plentiful python tools in data visualization, optimization, machine learning, etc. In this paper, we will introduce the features of pyJSPEC and demonstrate how to use it with sample codes and numerical results. 		 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA24  
About • Received ※ 02 August 2022 — Revised ※ 08 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 26 August 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPA33 Laser Stripping for 1.3 GeV H− Beam at the SNS laser, injection, photon, experiment 702
 
  • T.V. Gorlov, A.V. Aleksandrov, S.M. Cousineau, Y. Liu, A.R. Oguz
    ORNL, Oak Ridge, Tennessee, USA
  • M.J. Kay
    UTK, Knoxville, Tennessee, USA
  • P.K. Saha
    JAEA/J-PARC, Tokai-mura, Japan
  
  Funding: This work has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy.
A realistic full duty factor laser stripping charge exchange injection scheme for future 1.3 GeV beam at the SNS is considered. Different schemes of laser stripping involving combinations of photoexcitation, photoionization and magnetic field stripping are calculated. The laser power and magnetic field strength needed for different approaches are estimated and compared. The most practical scheme of laser stripping is selected for development. 		 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA33  
About • Received ※ 29 July 2022 — Revised ※ 05 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 23 August 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPA36 Emittance Growth Due to RF Phase Noise in Crab Cavities cavity, simulation, collider, betatron 708
 
  • H. Huang, S. Zhao
    ODU, Norfolk, Virginia, USA
  • F. Lin, V.S. Morozov
    ORNL RAD, Oak Ridge, Tennessee, USA
  • Y. Luo
    Brookhaven National Laboratory (BNL), Electron-Ion Collider, Upton, New York, USA
  • T. Satogata, Y. Zhang
    JLab, Newport News, Virginia, USA
  • B.P. Xiao, D. Xu
    BNL, Upton, New York, USA
  
  The Electron-Ion Collider (EIC) incorporates beam crabbing to recover geometric luminosity loss from the nonzero crossing angle at the interaction point (IP). It is well-known that crab cavity imperfections can cause growth of colliding beam emittances, thus degrading collider performance. Here we report a particle tracking study to quantify these effects. Presently the study is focused on crab cavity RF phase noise. Simulations were carried out using Bmad. Dependence of emittance growth on phase noise level was obtained which could be used for developing crab cavity phase control specifications. We also benchmarked these simulations with theory.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA36  
About • Received ※ 02 August 2022 — Revised ※ 07 August 2022 — Accepted ※ 12 August 2022 — Issue date ※ 02 September 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPA45 Practical Review on Beam Line Commissioning Procedures and Techniques for Scientific and Industrial Electron Accelerators electron, MMI, operation, linac 735
 
  • M.O. Kravchenko, R.D. Berry, A. Diego, D.I. Gavryushkin, M. Ruelas
    RadiaBeam, Santa Monica, California, USA
  
  Accelerator science has a constant demand requiring improved electron beam quality for both scientific and industrial applications. Examples of parameters on existing systems that affect overall beam quality include: vacuum stability, component level alignment, RF phase matching, electron injection parameters, etc. A proper beam commissioning process allows the characterization of initial parameters that tune system setup appropriately in order to improve net beam quality and becomes a valuable source of data to guide system operation. Here we will discuss methods and possible obstacles during the commissioning process of accelerator systems experienced at RadiaBeam. This includes a description of the diagnostic equipment that may be used to commission a beam line such as: current transformers, faraday cups, profile monitors and pyro detectors. The interpretation of raw data from the diagnostics in terms of usefulness for further adjustments and improvements on the beam line as shown in current work. Simulations and empirical comparisons are also presented as examples for commissioning procedures within the aspect of expectations and actual results.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA45  
About • Received ※ 30 July 2022 — Revised ※ 04 August 2022 — Accepted ※ 07 August 2022 — Issue date ※ 09 August 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPA69 The Impact on the Vertical Beam Dynamics Due to the Noise in a Horizontal Crab Crossing Scheme cavity, feedback, electron, hadron 788
 
  • Y. Hao
    BNL, Upton, New York, USA
  • Y. Luo
    Brookhaven National Laboratory (BNL), Electron-Ion Collider, Upton, New York, USA
  
  Funding: Work Supported BY Brookhaven Science Associates, LLC under contract NO. DE-SC0012704 with the U.S. Department of Energy.
Several recent and future colliders have adopted the crab crossing scheme to boost performance. The lower RF control noise of the crab cavities has been identified as one of the significant sources that impact the transverse beam quality in the crabbing plane. However, through beam-beam interaction and other coupling sources, the effect may also affect the non-crabbing plane. In this paper, we report the simulation observations of the beam dynamics in the non-crabbing plane in the presence of phase noise in the crab cavity. 		 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA69  
About • Received ※ 03 August 2022 — Revised ※ 07 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 06 September 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPA75 {6-D} Element-by-Element Particle Tracking with Crab Cavity Phase Noise and Weak-Strong Beam-Beam Interaction for the Hadron Storage Ring of the Electron-Ion Collider cavity, simulation, proton, electron 809
 
  • Y. Luo, J.S. Berg, M. Blaskiewicz, C. Montag, V. Ptitsyn, F.J. Willeke, D. Xu
    BNL, Upton, New York, USA
  • Y. Hao
    FRIB, East Lansing, Michigan, USA
  • H. Huang
    ODU, Norfolk, Virginia, USA
  • V.S. Morozov
    ORNL RAD, Oak Ridge, Tennessee, USA
  • J. Qiang
    LBNL, Berkeley, California, USA
  • T. Satogata
    JLab, Newport News, Virginia, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
The Electron Ion Collider (EIC) presently under construction at Brookhaven National Laboratory will collide polarized high energy electron beams with hadron beams with luminosity up to 1034 cm-2 s-1 in the center mass energy range of 20 to 140 GeV. Crab cavities are used to compensate the geometric luminosity due to a large crossing angle in the EIC. However, it was found that the phase noise in crab cavities will generate a significant emittance growth for hadron beams and its tolerance from analytical calculation is very small for the Hadron Storage Ring (HSR) of the EIC. In this paper, we report on 6-D symplectic particle tracking to estimate the proton emittance growth rate, especially in the vertical plane, for the HSR with weak-strong beam-beam and other machine or lattice errors. 		 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA75  
About • Received ※ 01 August 2022 — Revised ※ 06 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 19 August 2022
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WEPA77 A New PCB Rotating Coil at NSLS-II quadrupole, dipole, permanent-magnet, lattice 816
 
  • M. Musardo, J. Avronsart, F.A. DePaola, L. Doom, R. Faussete, F.C. Lincoln, S.K. Sharma, T. Tanabe
    BNL, Upton, New York, USA
  • D. Assell, J. DiMarco
    Fermilab, Batavia, Illinois, USA
  • A. Banerjee
    SBU, Stony Brook, New York, USA
  • C.L. Doose, A.K. Jain
    ANL, Lemont, Illinois, USA
  
  Several R&D projects are underway at NSLS-II towards an upgrade of its storage ring with a new lattice that will use high field magnets with small bores of 16-22 mm. A large fraction of the high field magnets are expected to be of permanent magnet technology that will require precise magnetic measurements and field harmonics corrections. A new magnetic measurement bench has been built based on a printed circuit board (PCB) coil of 12 mm diameter and 270 mm active length. This PCB coil has the capabil-ity of measuring field quality to a level of 10 ppm of the main field up to the 15th harmonic with a sensitivity between 0.01 m2 and 0.02 m2 at the reference radius of 5 mm. This paper will describe the main features of the rotating coil bench and discuss the measurement results of a permanent-magnet Halbach quadrupole of 12.7 mm bore diameter.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA77  
About • Received ※ 28 July 2022 — Revised ※ 06 August 2022 — Accepted ※ 12 August 2022 — Issue date ※ 29 August 2022
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WEPA78 Proton-Electron Focusing in EIC Ring Electron Cooler electron, focusing, proton, hadron 820
 
  • S. Seletskiy, A.V. Fedotov, D. Kayran, J. Kewisch
    BNL, Upton, New York, USA
  
  The Electron Ion Collider (EIC) requires a cooling of protons at the top energy. The Ring Electron Cooler (REC) is a suitable option for such a cooling. In this paper we consider an effect of a proton-electron space charge (SC) focusing on the quality of the electron beam in the REC. We show that, with properly adjusted parameters of the Ring Electron Cooler, the SC focusing in the REC cooling section does not significantly affect the cooler performance.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA78  
About • Received ※ 02 August 2022 — Revised ※ 03 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 20 August 2022
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THYD1 XFEL as a Low-Emittance Injector for a 4th-Generation Synchrotron Radiation Source electron, injection, storage-ring, synchrotron 850
 
  • T. Hara
    RIKEN SPring-8 Center, Hyogo, Japan
  
  Low-emittance beam injection is required for the future SPring-8-II due to its small injection beam aperture. To meet this requirement, the SACLA linac has been used as a low-emittance injector since 2020 [1]. In order to perform the beam injection in parallel with XFEL operation, three accelerators are virtually constructed in a control system for the two XFEL beamlines and the beam injection, and thus the accelerator parameters can be independently tuned. Since the reference clock frequencies of the two accelerators are not related by an integer multiple, a new timing system was developed that achieves 3.8 ps (rms) synchronization. To maintain bunch purity better than 1e-8, which is routinely requested at SPring-8, an electron sweeper and an RF knock-out system are introduced for the SACLA injector and the SPring-8 storage ring. Although 0.1 nm-rad emittance of SACLA is increased by an order of magnitude at a transport line mainly due to quantum excitation of synchrotron radiation, it is still small enough for SPring-8-II. By shutting down an old dedicated injector complex, energy consumption has been significantly reduced, and it contributes to create a low-carbon society.
The speaker present this work on behalf of RIKEN-JASRI project team.
[1] Toru Hara et al., Phys. Rev. Accel. Beams 24, 110702 (2021). 		 
slides icon Slides THYD1 [10.103 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-THYD1  
About • Received ※ 29 July 2022 — Revised ※ 05 August 2022 — Accepted ※ 07 August 2022 — Issue date ※ 23 September 2022
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FRXD3 Measurements of the Five-Dimensional Phase Space Distribution of an Intense Ion Beam simulation, neutron, rfq, quadrupole 910
 
  • A.M. Hoover, A.V. Aleksandrov, S.M. Cousineau, K.J. Ruisard, A.P. Zhukov
    ORNL, Oak Ridge, Tennessee, USA
  
  Funding: Supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics; authored by UT- Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy.
No simulation of intense beam transport has accurately reproduced measurements at the level of beam halo. One potential explanation of this discrepancy is a lack of knowledge of the initial distribution of particles in six-dimensional (6D) phase space. A direct 6D measurement of an ion beam was recently performed at the Spallation Neutron Source (SNS) Beam Test Facility (BTF), revealing nonlinear transverse-longitudinal correlations in the beam core that affect downstream evolution. Unfortunately, direct 6D measurements are limited in resolution and dynamic range; here, we discuss the use of three slits and one screen to measure a 5D projection of the 6D phase space distribution, overcoming these limitations at the cost of one dimension. We examine the measured 5D distribution before and after transport through the BTF and compare to particle-in-cell simulations. We also discuss the possibility of reconstructing the 6D distribution from 5D and 4D projections. 		 
slides icon Slides FRXD3 [4.078 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-FRXD3  
About • Received ※ 03 August 2022 — Revised ※ 09 August 2022 — Accepted ※ 12 August 2022 — Issue date ※ 02 September 2022
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