TUPA —  Poster Session   (09-Aug-22   16:30—18:00)
Chair: P.M. Anisimov, LANL, Los Alamos, New Mexico, USA
Paper Title Page
TUPA02 Characterization of Octupole Elements for IOTA 351
 
  • J.N. Wieland
    MSU, East Lansing, Michigan, USA
  • J.D. Jarvis, A.L. Romanov, A. Valishev
    Fermilab, Batavia, Illinois, USA
 
  Funding: Work partially supported by the US Department of Energy, Office of Science, High Energy Physics under Cooperative Agreement award number DE-SC0018362 and Michigan State University.
The Integrable Optics Test Accelerator (IOTA) is a research storage ring constructed and operated at Fermilab to demonstrate the advantages of nonlinear integrable lattices. One of the nonlinear lattice configurations with one integral of motion is based on a string of short octupoles. The results of the individual magnet’s characterizations, which were necessary to determine their multipole composition and magnetic centers, are presented. This information was used to select and align the best subset of octupoles for the IOTA run 4.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA02  
About • Received ※ 03 August 2022 — Revised ※ 08 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 08 September 2022
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TUPA04 Sheet Electron Probe for Beam Tomography 354
 
  • V.G. Dudnikov, M.A. Cummings, G. Dudnikova
    Muons, Inc, Illinois, USA
 
  Funding: Supported by DOE SBIR grant # DE-SC0021581.
We propose a new approach to electron beam tomography: we will generate a pulsed sheet of electrons. As the ion beam bunches pass through the sheet, they cause distortions in the distribution of sheet electrons arriving at a luminescent screen with a CCD device on the other side of the beam; these sheet electrons are interpreted to give a continuous measurement of the beam profile. The apparatus to generate the sheet beam is a strip cathode, which, compared to the scanning electron beam probe, is smaller, has simpler design and less expensive manufacturing, has better magnetic shielding, has higher sensitivity and higher resolution, has better accuracy of measurement, and has better time resolution.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA04  
About • Received ※ 22 July 2022 — Revised ※ 02 August 2022 — Accepted ※ 08 August 2022 — Issue date ※ 10 August 2022
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TUPA05 An H⁻ Injector for the ESS Storage Ring 357
 
  • V.G. Dudnikov, M.A. Cummings, M. Popovic
    Muons, Inc, Illinois, USA
 
  H charge exchange (stripping) injection into the European Spallation neutron Source (ESS) Storage Ring requires a 90 mA H ion source that delivers 2.9 ms pulses at 14 Hz repetition rate (duty factor ~4%) that can be extended to 28 Hz (df 8%). This can be achieved with a magnetron surface plasma H source (SPS) with active cathode and anode cooling. The Brookhaven National Laboratory (BNL) magnetron SPS can produce an H beam current of 100 mA with about 2 kW discharge power and can operate up to 0.7 % duty factor (average power 14 W) without active cooling. We describe how active cathode and anode cooling can be applied to the BNL source to increase the average discharge power up to 140 W (df 8%) to satisfy the needs of the ESS. We also describe the use of a short electrostatic LEBT as is used at the Oak Ridge National Laboratory Spallation Neutron Source to improve the beam delivery to the RFQ.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA05  
About • Received ※ 02 August 2022 — Revised ※ 08 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 04 September 2022
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TUPA09 Designing Accelerator-Driven Experiments for Accelerator-Driven Reactors 360
 
  • M.A. Cummings, R.J. Abrams, R.P. Johnsonpresenter, J.D. Lobo, T.J. Roberts
    Muons, Inc, Illinois, USA
 
  Muons, Inc., with its collaborators, to the best of our knowledge is the only one of the several reactor concept companies in the US that is concentrating on an accelerator-driven subcritical high-power reactor design. The major objection to such systems has been that short interruptions of beam of even a few seconds would turn off fission power long enough to induce temperature-gradient shocks and subsequent fatigue of solid fuel elements. Mu*STAR solves this problem by using a molten-salt fuel. Mu*STAR is a reactor design that not only includes a particle accelerator as an integral part, but has several innovative features that make it a compelling solution to many problems. We note that the ADSR concepts being pursued by the Chinese Academy of Science (ADANES) and the Belgians (MYRRHA) are based on traditional solid fuel elements and require exceptional stability from their accelerator.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA09  
About • Received ※ 03 August 2022 — Revised ※ 05 August 2022 — Accepted ※ 08 August 2022 — Issue date ※ 29 September 2022
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TUPA11 Magnet System for a Compact Microtron Source 363
 
  • S.A. Kahn, R.J. Abrams, M.A. Cummings, R.P. Johnson, G.M. Kazakevich
    Muons, Inc, Illinois, USA
 
  Funding: Work supported in part by U.S. D.O.E. SBIR grant DE-SC0013795.
A microtron can be an effective intense electron source. It can use less RF power than a linac to produce a similar energy because the beam will pass through the RF cavity several times. To produce a high-quality low-emittance beam with a microtron requires a magnetic system with a field uniformity $δ B/B<0.001. Field quality for a compact microtron with fewer turns is more difficult to achieve. In this study we describe the magnet for a compact S-band microtron that will achieve the necessary field requirements. The shaping of the magnet poles and shimming of the magnet iron at the outer extent of the poles will be employed to provide field uniformity. The extraction of the beam will be discussed.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA11  
About • Received ※ 04 August 2022 — Revised ※ 14 August 2022 — Accepted ※ 06 September 2022 — Issue date ※ 08 October 2022
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TUPA13 Affordable, Efficient Injection-Locked Magnetrons for Superconducting Cavities 366
 
  • M. Popovic, M.A. Cummings, R.P. Johnson, S.A. Kahnpresenter, R.R. Lentz, M.L. Neubauer, T. Wynn
    Muons, Inc, Illinois, USA
  • T. Blassick, J.K. Wessel
    Richardson Electronics Ltd, Lafox, Illinois, USA
 
  Funding: DE-SC0022586.
Existing magnetrons that are typically used to study methods of control or lifetime improvements for SRF accelerators are built for much different applications such kitchen microwave ovens (1kW, 2.45 GHz) or industrial heating (100 kW, 915 MHz). In this project, Muons, Inc. will work with an industrial partner to develop fast and flexible manufacturing techniques to allow many ideas to be tested for construction variations that enable new phase and amplitude injection locking control methods, longer lifetime, and inexpensive refurbishing resulting in the lowest possible life-cycle costs. In Phase II magnetron sources will be tested on SRF cavities to accelerate an electron beam at JLab. A magnetron operating at 650 MHz will be constructed and tested with our novel patented subcritical voltage operation methods to drive an SRF cavity. The choice of 650 MHz is an optimal frequency for magnetron efficiency. The critical areas of magnetron manufacturing and design affecting life-cycle costs that will be modeled for improvement include: Qext, filaments, magnetic field, vane design, and novel control of outgassing.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA13  
About • Received ※ 05 August 2022 — Revised ※ 11 August 2022 — Accepted ※ 12 August 2022 — Issue date ※ 23 August 2022
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TUPA14 Fast First-Order Spin Propagation for Spin Matching and Polarization Optimization with Bmad 369
 
  • J.M. Asimow, G.H. Hoffstaetter, D. Saganpresenter, M.G. Signorelli
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  Accurate spin tracking is essential for the simulation and propagation of polarized beams, in which a majority of the particles’ spin point in the same direction. Bmad, an open-sourced library for the simulation of charged particle dynamics, traditionally tracks spin via integrating through each element of a lattice. While exceptionally accurate, this method has the drawback of being slow; at best, the runtime is proportional to the length of the element. By solving the spin transport equation for simple magnet elements, Bmad can reduce this algorithm to constant runtime while maintaining high accuracy. This method, known as "Sprint," enables quicker spin matching and prototyping of lattice designs via Bmad.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA14  
About • Received ※ 30 July 2022 — Revised ※ 09 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 24 August 2022
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TUPA15 Development of a CVD System for Next-Generation SRF Cavities 372
 
  • G. Gaitan, P. Bishop, A.T. Holic, G. Kulina, J. Sears, Z. Sun
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • M. Liepe
    Cornell University, Ithaca, New York, USA
  • B.W. Wendland
    University of Minnesota, Minnesota, USA
 
  Funding: This research is funded by the National Science Foundation under Grant No. PHY-1549132, the Center for Bright Beams.
Next-generation, thin-film surfaces employing Nb3Sn, NbN, NbTiN, and other compound superconductors are destined to allow reaching superior RF performance levels in SRF cavities. Optimized, advanced deposition processes are required to enable high-quality films of such materials on large and complex-shaped cavities. For this purpose, Cornell University is developing a remote plasma-enhanced chemical vapor deposition (CVD) system that facilitates coating on complicated geometries with a high deposition rate. This system is based on a high-temperature tube furnace with a clean vacuum and furnace loading system. The use of plasma alongside reacting precursors will significantly reduce the required processing temperature and promote precursor decomposition. The system can also be used for annealing cavities after the CVD process to improve the surface layer. The chlorine precursors have the potential to be corrosive to the equipment and pose specific safety concerns. A MATLAB GUI has been developed to control and monitor the CVD system at Cornell.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA15  
About • Received ※ 14 July 2022 — Revised ※ 08 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 22 August 2022
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TUPA16 Singularity-Free Exact Dipole Bend Transport Equations 375
 
  • D. Sagan
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  Funding: Department of Energy
Exact transport equations for a pure dipole bend (a bend with a dipole field and nothing else) have been derived and formulated to avoid singularities when evaluated. The transport equations include finite edge angles and no assumption is made in terms of the bending field being matched to the curvature of the coordinate system.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA16  
About • Received ※ 05 August 2022 — Revised ※ 09 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 16 September 2022
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TUPA17 Beam-Based Alignment of Sextupole Families in the EIC 378
 
  • J.C. Wang, G.H. Hoffstaetter, D. Saganpresenter
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • C. Montag
    BNL, Upton, New York, USA
 
  To steer the closed orbit in a storage ring through the center of its quadrupoles, it is important to accurately know the quadrupole centers relative to nearby beam position monitors. Usually this is achieved by beam-based alignment (BBA). Assuming the quadrupole strength can be changed individually, one finds the BPM reading where changing a quadrupole’s strength does not alter the closed orbit. Since most quadrupoles are powered in series, they can only be varied independently if costly power supplies are added. For the EIC electron storage ring (ESR), we investigate whether sextupole BBA can be used instead. Individually powered sextupole BBA techniques already exist, but most sextupoles are powered in families and cannot be individually changed. We therefore developed a method where a localized bump changes the beam excursion in a single sextupole of a family, turning off all families that also have sextupoles in the bump. The bump amplitude at which the sextupole does not cause a closed orbit kick determines the sextupole’s alignment. This study was made to investigate the precision to which this method can be utilized.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA17  
About • Received ※ 04 August 2022 — Revised ※ 08 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 29 August 2022
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TUPA18 Promise and Challenges of a Method for 5x5 Sigma Matrix Measurement in a Transport Line 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  
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TUPA19 Avoiding Combinatorial Explosion in Simulation of Multiple Magnet Errors in Swap-Out Safety Tracking for the Advanced Photon Source Upgrade 386
 
  • M. Borland, R. Soliday
    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 hybrid seven-bend-achromat design with reverse bends, providing a natural emittance of 41 pm at 6 GeV. The small dynamic acceptance entails operation in on-axis swap-out mode. Careful consideration is required of the safety implications of injection with shutters open. Tracking studies require simulation of multiple simultaneous magnet errors, some combinations of which may introduce potentially dangerous conditions. A naive grid scan of possible errors, while potentially very complete, would be prohibitively time-consuming. We describe a different approach using biased sampling of particle distributions from successive scans. We also describe other aspects of the simulations, such as use of 3D field maps and a highly detailed aperture model.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA19  
About • Received ※ 01 August 2022 — Revised ※ 07 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 10 September 2022
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TUPA21 Hydrodynamic and Beam Dynamic Simulations of Ultra-Low Emittance Whole Beam Dumps in the Advanced Photon Source Storage Ring 390
 
  • J.C. Dooling, M. Borland, A.M. Grannan, C.J. Graziani, Y. Lee, R.R. Lindberg, G. Navrotski
    ANL, Lemont, Illinois, USA
  • N.M. Cook
    RadiaSoft LLC, Boulder, Colorado, USA
  • D.W. Lee
    UCSC, Santa Cruz, California, USA
 
  Funding: Work supported by Accelerator Science and Technology LDRD Project 2021-0119 and 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 use a multi-bend achromatic lattice to reduce vertical and horizontal beam emittances by one- and two-orders of magnitude respectively; in addition operating current will double. The resulting electron beam will be capable of depositing more than 150 MGy on machine protection collimators creating high-energy-density conditions. Work is underway to couple the beam dynamics code Elegant with the particle-matter interaction program MARS and the magnetohydrodynamics code FLASH to model the effects of whole beam dumps on the collimators. Loss distributions from Elegant are input to MARS which provide dose maps to FLASH. We also examine the propagation of downstream shower components after the beam interacts with the collimator. Electrons and positrons are tracked to determine locations of beam loss. Beam dump experiments conducted in the APS storage-ring, generated dose levels as high as 30 MGy resulting in severe damage to the collimator surfaces with melting in the bulk. The deformed collimator surface may lead to beam deposition in unexpected locations. A fan-out kicker is planned to mitigate the effects of whole beam dumps on the collimators.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA21  
About • Received ※ 02 August 2022 — Revised ※ 10 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 10 September 2022
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TUPA22 Measurements of Bunch Length in the Advanced Photon Source Booster Synchrotron 394
 
  • J.C. Dooling, W. Berg, J.R. Calvey, K.C. Harkay, K.P. Wootton
    ANL, Lemont, Illinois, USA
 
  Funding: Work supported by the U.S. D.O.E.,Office of Science, Office of Basic Energy Sciences, under contract number DE-AC02- 06CH11357.
A bunch duration monitor (BDM) was installed at the end of a synchrotron light monitor (SLM) port in the Advanced Photon Source (APS) booster synchrotron. The BDM is based on a fast Hamamatsu metal-semiconductor-metal detector with nominal rise and fall times of 30 ps. Bunch length data is especially important as the bunch charge will be raised from 3 nC, used in the existing machine, to as much as 18 nC for APS-Upgrade operation. During preliminary high-charge studies, the SLM image is observed to move over a period of minutes while the BDM signal intensity varies; the motion is likely due to thermal loading of the in-tunnel synchrotron light mirror. Work is underway to stabilize the position using a simple feedback system and motorized mirror mount, as well as a new synchrotron light mirror assembly with improved thermal load handling. The feedback system will maintain optical alignment on the BDM at an optimum position based on the SLM centroid location. The optical layout and feedback system will be presented along with preliminary bunch length data.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA22  
About • Received ※ 04 August 2022 — Revised ※ 09 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 09 September 2022
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TUPA23 First Beam Results Using the 10-kW Harmonic Rf Solid-State Amplifier for the APS Particle Accumulator Ring 398
 
  • K.C. Harkay, T.G. Berenc, J.R. Calvey, J.C. Dooling, H. Shang, T.L. Smith, Y. Sun, U. Wienands
    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 (APS) particle accumulator ring (PAR) was designed to accumulate linac pulses into a single bunch using a fundamental radio frequency (rf) system, and longitudinally compress the beam using a harmonic rf system prior to injection into the booster. The APS Upgrade injectors will need to supply full-current bunch replacement with high single-bunch charge for swap-out injection in the new storage ring. Significant bunch lengthening is observed in the PAR at high charge, which negatively affects beam capture in the booster. Predictions showed that the bunch length could be compressed to better match the booster acceptance using a combination of higher beam energy and higher harmonic gap voltage. A new 10-kW harmonic rf solid-state amplifier (SSA) was installed in 2021 to raise the gap voltage and improve bunch compression. The SSA has been operating reliably. Initial results show that the charge-dependent bunch lengthening in PAR with higher gap voltage agrees qualitatively with predictions. A tool was written to automate bunch length data acquisition. Future plans to increase the beam energy, which makes the SSA more effective, will also be summarized.
 
poster icon Poster TUPA23 [2.477 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA23  
About • Received ※ 03 August 2022 — Revised ※ 05 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 07 October 2022
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TUPA26 Fringe Field Maps for Cartesian Dipoles with Longitudinal and/or Transverse Gradients 401
 
  • 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.
Fringe fields effects in dipoles can give rise to important linear and nonlinear contributions. This paper describes how to extend the classic results of Brown [1] and the more recent calculations of Hwang and Lee [2] to Cartesian dipoles with transverse and/or longitudinal gradients. We do this by 1) introducing a more general definition of the fringe field that can be applied to longitudinal gradient dipoles, 2) allowing for quadrupole and/or sextupole content in the magnet body, and 3) showing how to employ the resulting fringe field maps as a symplectic transformation of the coordinates. We compare our calculation results with tracking for longitudinal and transverse gradient dipoles planned for the APS-U.
[1] K.L. Brown, Report SLAC-75, 1982.
[2] K. Hwang and S.Y. Lee, Phys. Rev. Accel. Beams, vol. 18, p. 122401 2015.
 
poster icon Poster TUPA26 [2.090 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA26  
About • Received ※ 26 July 2022 — Revised ※ 11 August 2022 — Accepted ※ 12 August 2022 — Issue date ※ 21 August 2022
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TUPA27 Longitudinal Feedback Dynamics in Storage Rings with Small Synchrotron Tunes 405
 
  • R.R. Lindberg
    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 analyze the dynamics of multibunch longitudinal instabilities including bunch-by-bunch feedback under the assumption that the synchrotron tune is small. We find that increasing the feedback response does not always guarantee stability, even in the ideal case with no noise. As an example, we show that if the growth rate of a cavity-driven mode is of the order of the synchrotron frequency, then there are parameter regions for which the instability cannot be controlled by feedback irrespective of its gain. We verify these calculations with tracking simulations relevant to the APS-U, and find that the dynamics do not depend upon whether the longitudinal feedback relies on phase-sensing or energy-sensing technology. Hence, this choice should be dictated by measurement accuracy and noise considerations.
 
poster icon Poster TUPA27 [1.180 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA27  
About • Received ※ 26 July 2022 — Revised ※ 05 August 2022 — Accepted ※ 07 August 2022 — Issue date ※ 26 August 2022
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TUPA28 Update on the Development of a Low-Cost Button BPM Signal Detector at AWA 409
 
  • W. Liu, G. Chen, D.S. Doran, S.Y. Kimpresenter, X. Lu, P. Piot, J.G. Power, C. Whiteford, E.E. Wisniewski
    ANL, Lemont, Illinois, USA
  • E.E. Wisniewski
    IIT, Chicago, Illinois, USA
 
  Funding: Work supported by the US Department of Energy, Office of Science.
A single-pulse, high dynamic range, cost-effective BPM signal detector has been on the most wanted list of the Argonne Wakefield Accelerator (AWA) Test Facility for many years. The unique capabilities of the AWA beamline require BPM instrumentation with an unprecedented dynamic range, thus a cost-effective solution could be challenging to design and prototype. With the help of a better circuit model for a button BPM signal source, we are able to do the circuit simulations with more realistic input signals and make predictions much closer to realities. Our most recent design and prototype results are shared in this paper.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA28  
About • Received ※ 01 August 2022 — Revised ※ 08 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 09 October 2022
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TUPA29 Machine Learning for Predicting Power Supply Trips in Storage Rings 413
 
  • I. Lobach, M. Borland, G.I. Fystro, A. Sannibale, Y. Sun
    ANL, Lemont, Illinois, USA
  • A. Diaw, J.P. Edelen
    RadiaSoft LLC, Boulder, Colorado, 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.
In the Advanced Photon Source (APS) storage ring at Argonne National Lab, trips in the magnet power supplies (PSs) lead to a complete electron beam loss a few times a year. This results in unexpected interruptions of the users’ experiments. In this contribution, we investigate the historical data for the last two decades to find precursors for the PS trips that could provide an advance notice for future trips and allow some preventive action by the ring operator or by the PS maintenance team. Various unsupervised anomaly detection models can be trained on the vast amounts of available reference data from the beamtime periods that ended with an intentional beam dump. We find that such models can sometimes detect trip precursors in PS currents, voltages, and in the temperatures of magnets, capacitors and transistors (components of PSs).
 
poster icon Poster TUPA29 [2.116 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA29  
About • Received ※ 03 August 2022 — Revised ※ 07 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 18 August 2022
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TUPA30 Development of a Compact 2D Carbon Beam Scanner for Cancer Therapy 417
 
  • B. Mustapha, A. Barcikowski, J.A. Nolen
    ANL, Lemont, Illinois, USA
  • V.P. Derenchuk, P. Osucha
    ProNova Solutions, Knoxville, USA
  • N. Tsoupas
    BNL, Upton, New York, USA
 
  Funding: This work was supported by the U.S. Department of Energy, under Contract No. DE-AC02-06CH11357. This research was support through the DOE’s Accelerator Stewardship program.
A novel trapezoidal coil 2D carbon beam scanner has been designed, and a prototype has been successfully developed and tested. The field performance of the magnet has been characterized and it is in excellent agreement with the simulations. A better than 1% field uniformity in both planes has been achieved within the useful aperture of the magnet. This represents a significant improvement over the prior art of the elephant-ear scanner design. A comparison of the two designs and the results from the new trapezoidal-coil design will be presented and discussed. Higher power and online beam testing are planned in the near future.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA30  
About • Received ※ 25 July 2022 — Revised ※ 14 August 2022 — Accepted ※ 15 August 2022 — Issue date ※ 25 August 2022
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TUPA32 SCU Ends Configured as Phase Shifter 420
 
  • M.F. Qian
    ANL, Lemont, Illinois, USA
 
  Funding: Work supported by LDRD funding from Argonne National Laboratory, provided by the Director, Office of Science, of the U.S. DOE under Contract No. DE-AC02-06CH11357.
Dipole correctors and phase shifters are usually needed in the interspace of a permanent magnet (PM)-based undulator array for purposes of beam steering and phase matching when the field strength is changing. Unlike the PM-based undulators, the superconducting undulator (SCU) can change its end field with the help of varying currents in the end coils. By setting the end coil currents the beam-steering and the phase-matching could be realized, thus eliminating the need for standalone correctors and phase shifters, saving the interspace as well as reducing the mechanical complexity of an undulator array. We developed a procedure for determining the SCU end coil currents and verified it by numerical simulations. The procedure as well as the simulation results are described in this paper.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA32  
About • Received ※ 03 August 2022 — Revised ※ 08 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 07 September 2022
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TUPA33 Magnetic Field Calculation of Superconducting Undulators for FEL Using Maxwell 3D 423
 
  • Y. Shiroyanagi, Y. Ivanyushenkov, M. Kasa
    ANL, Lemont, Illinois, USA
 
  Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
An ANL-SLAC collaboration is working on design of a planar superconducting undulator (SCU) demonstrator for a FEL. As a part of this project, a SCU magnet prototype is planned to be built and tested. A planar SCU magnet consisting of a 1.0-m-long segment is being designed. Although OPERA is a standard tool for magnetic field calculation, ANSYS Maxwell 3D can also be used for a large and complex geometry. An ANSYS calculated magnetic field was benchmarked with the measured field profile of existing SCUs. This paper presents calculations of magnetic field and field integrals of 0.5-m-long and 1.0-m-long planar SCUs with a new end correction scheme. Then, an external phase shifter is also incorporated into the model. A cross-talk between a phase shifter and SCU magnetic structures is also presented.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA33  
About • Received ※ 02 August 2022 — Revised ※ 03 August 2022 — Accepted ※ 05 August 2022 — Issue date ※ 25 August 2022
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TUPA34 Model-Based Calibration of Control Parameters at the Argonne Wakefield Accelerator 427
 
  • I.P. Sugrue, B. Mustapha, P. Piot, J.G. Power
    ANL, Lemont, Illinois, USA
  • N. Krislock
    Northern Illinois University, DeKalb, Illinois, USA
 
  Particle accelerators utilize a large number of control parameters to generate and manipulate beams. Digital models and simulations are often used to find the best operating parameters to achieve a set of given beam parameters. Unfortunately, the optimized physics parameters cannot precisely be set in the control system due to, e.g., calibration uncertainties. We developed a data-driven physics-informed surrogate model using neural networks to replace digital models relying on beam-dynamics simulations. This surrogate model can then be used to perform quick diagnostics of the Argonne Wakefield accelerator in real time using nonlinear least-squares methods to find the most likely operating parameters given a measured beam distribution.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA34  
About • Received ※ 05 August 2022 — Revised ※ 09 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 24 September 2022
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TUPA36 The Advanced Photon Source Linac Extension Area Beamline 430
 
  • K.P. Wootton, W. Berg, J.M. Byrd, J.C. Dooling, G.I. Fystro, A.H. Lumpkin, Y. Sun, A. Zholents
    ANL, Lemont, Illinois, USA
  • C.C. Hall
    RadiaSoft LLC, Boulder, Colorado, USA
 
  Funding: This research used resources of the Advanced Photon Source, operated for the U.S. Department of Energy Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.
The Linac Extension Area at the Advanced Photon Source is a flexible beamline area for testing accelerator components and techniques. Driven by the Advanced Photon Source electron linac equipped with a photocathode RF electron gun, the Linac Extension Area houses a 12 m long beamline. The beamline is furnished with YAG screens, BPMs and a magnetic spectrometer to assist with characterization of beam emittance and energy spread. A 1.4 m long insertion in the middle of the beamline is provided for the installation of a device under test. The beamline is expected to be available soon for testing accelerator components and techniques using round and flat electron beams over an energy range 150-450 MeV. In the present work, we describe this beamline and summarise the main beam parameters.
 
poster icon Poster TUPA36 [0.892 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA36  
About • Received ※ 02 August 2022 — Revised ※ 08 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 19 September 2022
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TUPA37 A Distributed Beam Loss Monitor Based upon Activation of Oxygen in Deionised Cooling Water 433
 
  • K.P. Wootton
    ANL, Lemont, Illinois, USA
 
  Funding: This research used resources of the Advanced Photon Source, operated for the U.S. Department of Energy Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.
We propose a novel beam loss detection scheme whereby activation of deionised cooling water is used to observe elevated radiation around the APS storage ring. This is based on radioactivation of oxygen within deionised cooling water by gamma rays above 10 MeV and neutrons above 15 MeV. Losses would be detected using a gamma ray detector monitoring process water flow out of the accelerator enclosure. We anticipate that this could be used to provide a segmented, distributed loss monitor system covering the accelerator components closest to locations where radiation is generated.
 
poster icon Poster TUPA37 [0.528 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA37  
About • Received ※ 02 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 26 September 2022  
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TUPA38 Sublinear Intensity Response of Cerium-Doped Yttrium Aluminium Garnet Screen with Charge 437
 
  • K.P. Wootton, A.H. Lumpkin
    ANL, Lemont, Illinois, USA
 
  Funding: This research used resources of the Advanced Photon Source, operated for the U.S. Department of Energy Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.
Swap-out injection to the Advanced Photon Source Upgrade storage ring necessitates the injection of ~17 nC electron bunches at 6 GeV. To aid with machine tune-up and to measure the beam size, diagnostic imaging screens are envisaged at several locations in the beam transport line from the booster synchrotron to the storage ring. As such, it is important to determine whether the response of these screens to charge is linear. In the present work, we examine the effect of sublinear intensity quenching of a Cerium-doped Yttrium-Aluminium-Garnet scintillator screen. A 1.3 megapixel FLIR BlackFly monochrome digital camera was used to image the beam at the scintillator. At 7 GeV beam energy, over the charge densities investigated (<10 fC um-2), an approximately 10 % reduction of the imaging intensity due to quenching of the scintillator was observed.
 
poster icon Poster TUPA38 [0.557 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA38  
About • Received ※ 02 August 2022 — Accepted ※ 03 August 2022 — Issue date ※ 09 August 2022  
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TUPA41 Applications of Machine Learning in Photo-Cathode Injectors 441
 
  • A. Aslam
    UNM-ECE, Albuquerque, USA
  • M. Babzien
    BNL, Upton, New York, USA
  • S. Biedron
    Element Aero, Chicago, USA
 
  To configure a photoinjector to reproduce a given electron bunch with the desired characteristics, it is necessary to adjust the operating parameters with high precision. More or less, the fine tunability of the laser parameters are of extreme importance as we try to model further applications of the photoinjector. The laser pulse incident on the photocathode critically affects the electron bunch 3D phase space. Parameters such as the laser pulse transverse shape, total energy, and temporal profile must be controlled independently, any laser pulse variation over both short and long-time scales also requires correction. The ability to produce arbitrary laser intensity distributions enables better control of electron bunch transverse and longitudinal emittance by affecting the space-charge forces throughout the bunch. In an accelerator employing a photoinjector, electron optics in the beamline downstream are used to transport, manipulate, and characterize the electron bunch. The adjustment of the electron optics to achieve a desired electron bunch at the interaction point is a much better understood problem than laser adjustment, so this research emphasizes laser shaping.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA41  
About • Received ※ 30 July 2022 — Revised ※ 12 August 2022 — Accepted ※ 13 August 2022 — Issue date ※ 07 September 2022
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TUPA42 LANSCE Modernization Project at LANL 443
 
  • D.V. Gorelov, J. Barraza, D.A.D. Dimitrov, I. Draganić, E. Henestroza, S.S. Kurennoy
    LANL, Los Alamos, New Mexico, USA
 
  In the framework of LANSCE Accelerator Modernization Project preliminary research, during evaluation of critical technology elements it was found that the proposed RFQ design had not yet been demonstrated experimentally worldwide. Such an RFQ should combine the ability of traditional light ion RFQs (i.e., [1]) and the flexibility of acceleration of pre-bunched beams, like RFQs for heavy ions [2]. The proposed RFQ should be able to accelerate H+ and H beams with 35-mA beam current from 100 keV to 3 MeV and at the same time preserve the prescribed macro-bunch beam time structure required by experiments. New algorithms for RFQ geometry generation have been proposed, and optimization algorithms are being developed at LANL. LAMP demonstration plans also include development of a new set of electrodes for the existing RFQ at our Test Stand that will allow us to demonstrate the critical technology ahead of time in a laboratory experimental setup with low duty factor and low energy.
[1] S. Henderson et al., Nucl. Instrum. Methods Phys. Res., Sect. A, v. 763, pp. 610-673 (2014).
[2] H. Ren et al., J. Phys. Conf. Ser., v. 1067, 052010 (2018).
 
poster icon Poster TUPA42 [0.635 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA42  
About • Received ※ 04 August 2022 — Revised ※ 05 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 18 August 2022
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TUPA43 Novel RF Phase Detector for Accelerator Applications 446
 
  • J.M. Potter
    JP Accelerator Works, Los Alamos, New Mexico, USA
 
  A novel phase detector has been developed that is suitable for use in an rf phase locked loop for locking an rf source to an rf accelerator structure or phase locking the accelerator structure to a fixed or adjustable frequency rf source. It is also useful for fast phase feedback to control the phase of an accelerator rf field. The principle is applicable to a wide range of frequencies and amplitudes. The phase is uniquely and unambiguously determined over 360°, eliminating the need for external phase shifters or phase references. The operation of this phase detector is described in detail. An application is described that uses a DDS-based LLRF source as the rf input to a high-power rf system.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA43  
About • Received ※ 02 August 2022 — Revised ※ 04 August 2022 — Accepted ※ 05 August 2022 — Issue date ※ 06 October 2022
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TUPA44 A Personal History of the Development of the LAMPF/LANSCE Accelerator 449
 
  • J.M. Potter
    JP Accelerator Works, Los Alamos, New Mexico, USA
 
  The LAMPF/LANSCE accelerator has now been operational for 50 years. I arrived as a LASL employee in Group P11 in April 1964 at the beginning stages of its development. I participated in the development of the resonant coupling principle [1] and went on to develop tuning procedures for the 805-MHz coupled cavity linac (CCL) structures and the post-stabilized drift tube linac (DTL) [2]. The resonant coupling principle is now well established as the basis for rf linear accelerators worldwide. I will discuss the development and building of the accelerator from my viewpoint as a member of a large, dedicated team of physicists, engineers, technicians, and support personnel.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA44  
About • Received ※ 02 August 2022 — Revised ※ 04 August 2022 — Accepted ※ 05 August 2022 — Issue date ※ 05 September 2022
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TUPA47 Upgrade from ADCs with Centrally Scheduled Triggers to Continually Triggered Waveform Digitizers 452
 
  • S.A. Baily, B.C. Atencio, A.J. Braido, C.D. Hatch, J.O. Hill, S.M. Johnson, L.S. Kennel, M. Pieck, L.E. Walker, H.A. Watkins, E.E. Westbrook, K. Xu, D.D. Zimmermann
    LANL, Los Alamos, New Mexico, USA
 
  The Los Alamos Neutron Science Center (LANSCE) control system includes many data channels that are timed and flavored, i.e., users can specify the species of beam and time within the beam pulse at which data are reported. The legacy LANSCE control system accom-plished this task by queuing up application software-initiated requests and scheduling Analog to Digital Con-verter (ADC) readout with custom programmable time-delay gated and multiplexed Remote Information and Control Equipment (RICE). This year we upgraded this system to a new Experimental Physics and Industrial Control System (EPICS) system that includes signal ded-icated waveform digitizer. An appropriate subset of the data is then returned as specified by each client. This is made possible by improvements to EPICS software, a Commercial Off-The-Shelf (COTS) Field Programmable Gate Array (FPGA) Mezzanine Card (FMC) based ADC and a COTS VPX FPGA card with EPICS embedded on a soft-core processor. This year we upgraded over 1200 waveform channels from RICE to the new TDAQ (Timed/flavored Data Acquisition) system.
LA-UR-22-27932
 
poster icon Poster TUPA47 [1.379 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA47  
About • Received ※ 02 August 2022 — Revised ※ 08 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 05 October 2022
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TUPA48 Effect of Lattice Misalignments on Beam Dynamics in LANSCE Linear Accelerator 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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TUPA52 Initial Results of the 201.25 MHz Coaxial Window Test Stand 458
 
  • T.W. Hall, J.T.M. Lyles, A. Poudel, A.S. Waghmare
    LANL, Los Alamos, New Mexico, USA
 
  We have recently commissioned an RF window test stand for the Drift Tube Linear Accelerator (DTL) portion of the Los Alamos Neutron Science Center (LANSCE). The window test stand consists of two RF windows that create a vacuum chamber which allows the windows to be tested to the peak power levels used in the DTL. Initial results clearly indicated multipactoring due to the increase of pressure at specific regions of peak forward power levels. Temperature measured at various azimuthal locations on both windows showed increased multipactor heating on the downstream window versus the upstream window. We present the effect of the titanium nitride coating that is presently applied to windows on both multipactor and window temperature. These results are discussed with respect to their impact on the LANSCE DTL performance.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA52  
About • Received ※ 25 July 2022 — Revised ※ 04 August 2022 — Accepted ※ 05 August 2022 — Issue date ※ 07 September 2022
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TUPA53 Modeling of Nonlinear Beam Dynamics via a Novel Particle-Mesh Method and Surrogate Models with Symplectic Neural Networks 462
 
  • C.-K. Huang, O. Beznosov, J.W. Burby, B.E. Carlsten, G.A. Dilts, J. Domine, R. Garimella, A. Kim, T.J. Kwan, H.N. Rakotoarivelo, R.W. Robey, B. Shen, Q. Tang
    LANL, Los Alamos, New Mexico, USA
  • F.Y. Li
    New Mexico Consortium, Los Alamos, USA
 
  Funding: Work supported by the LDRD program at Los Alamos National Laboratory and the ASCR SciML program of DOE.
The self-consistent nonlinear dynamics of a relativistic charged particle beam, particularly through the interaction with its complete self-fields, is a fundamental problem underpinning many accelerator design issues in high brightness beam applications, as well as the development of advanced accelerators. A novel self-consistent particle-mesh code, CoSyR [1], is developed based on a Lagrangian method for the calculation of the beam particles’ radiation near-fields and associated beam dynamics. Our recent simulations reveal the slice emittance growth in a bend and complex interplay between the longitudinal and transverse dynamics that are not captured in the 1D longitudinal static-state Coherent Synchrotron Radiation (CSR) model. We further show that surrogate models with symplectic neural networks can be trained from simulation data with significant time-savings for the modeling of nonlinear beam dynamics effects. Possibility to extend such surrogate models for the study of spin-orbital coupling is also briefly discussed.
[1] C.-K. Huang et al., Nucl. Instruments Methods Phys. Res. Sect. A, vol. 1034, p. 166808, 2022.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA53  
About • Received ※ 25 July 2022 — Revised ※ 03 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 11 August 2022
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TUPA55 Progress Toward Improving Accelerator Performance and Automating Operations with Advanced Analysis Software 465
 
  • J.E. Koglin, J.E. Coleman, M. McKerns, D. Ronquillo, A. Scheinker
    LANL, Los Alamos, New Mexico, USA
 
  Funding: Research presented in this conference paper was supported by the Laboratory Directed Research and Development program of Los Alamos National Laboratory under project numbers XXG2, XX8R and XXB6.
The penetrating radiography provided by the Dual Axis Radiographic Hydrodynamic Test (DARHT) facility is a key capability in executing a core mission of the Los Alamos National Laboratory (LANL). A new suite of software is being developed in the Python programming language to support operations of the of two DARHT linear induction accelerators (LIAs). Historical data, built as hdf5 data structures for over a decade of operations, are being used to develop automated failure and anomaly detection software and train machine learning models to assist in beam tuning. Adaptive machine learning (AML) that incorporate physics-based models are being designed to use non-invasive diagnostic measurements to address the challenge of time variation in accelerator performance and target density evolution. AML methods are also being developed for experiments that use invasive diagnostics to understand the accelerator behavior at key locations, the results of which will be fed back into the accelerator models. The status and future outlook for these developments will be reported, including how Jupyter notebooks are being used to rapidly deploy these advances as highly-interactive web applications.
 
poster icon Poster TUPA55 [1.919 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA55  
About • Received ※ 15 July 2022 — Revised ※ 08 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 12 August 2022
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TUPA56 Beam Coupling Impedances of Asymmetric Components of the Scorpius Induction Linac 469
 
  • S.S. Kurennoy
    LANL, Los Alamos, New Mexico, USA
 
  The transverse beam coupling impedance of induction linacs must be minimized to avoid beam breakdown instability. The vacuum chamber of the Scorpius linac contains complicated asymmetric elements. We present calculations of the transverse impedance for three asymmetric discontinuities: (1) a pumping section between accelerating cells, which contains vacuum plenum, pumping grid, and bellows; (2) a fast flapper valve; and (3) a debris blocker at the end of the linac. The dipole transverse impedance is calculated with CST Studio using both wakefield solver and eigen solver.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA56  
About • Received ※ 01 August 2022 — Revised ※ 07 August 2022 — Accepted ※ 08 August 2022 — Issue date ※ 06 October 2022
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TUPA57 Electromagnetic and Beam Dynamics Modeling of the LANSCE Coupled-Cavity Linac 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
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TUPA58 Iterative Tuning of the Beam Feedforward Controller for LANSCE LINAC Digital Low Level RF Control System 475
 
  • S. Kwon, A.T. Archuleta, L.J. Castellano, M.S. Prokop, C. Rose, P.A. Torrez, P. Van Rooypresenter
    LANL, Los Alamos, New Mexico, USA
 
  Funding: USDOE
This paper addresses an iterative particle beam phase and amplitude feedforward controller tuning method based on the gradient search approach. The method does not need an a priori plant model as it only needs data collected in previous experimental runs. The controller is implemented on a field programmable gate array (FPGA) equipped with a real-time operating system and a network connection. Data from each RF pulse is collected and sent via the network to the FPGA for processing. The controller tuning is performed between the RF pulses. Once the tuning is performed, the controller parameters are downloaded to the controller in the FPGA and new controller parameters are applied at the upcoming RF pulse
 
poster icon Poster TUPA58 [0.998 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA58  
About • Received ※ 01 August 2022 — Revised ※ 09 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 07 September 2022
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TUPA59 RF System Upgrade for Low Energy DTL Cavity at LANSCE 478
 
  • J.T.M. Lyles, R.E. Bratton, T.W. Hall, M. Sanchez Barrueta
    LANL, Los Alamos, New Mexico, USA
 
  Funding: Work supported by the United States Department of Energy, National Nuclear Security Agency, under contract 89233218CNA000001.
The Los Alamos Neutron Science Center (LANSCE) 100-MeV Drift Tube Linac (DTL) uses four accelerating cavities. In May of 2021, a new RF amplifier system was commissioned to drive the first 4-MeV cavity. It had been powered for 30 years with a triode vacuum tube RF amplifier driven by a tetrode, along with four more vacuum tubes for anode high-voltage modulation. The new amplifier system uses one tetrode amplifier driven by a 20-kW solid state amplifier (SSA) to generate 400 kWp at 201.25 MHz. The tetrode amplifier is protected for reflected power from the DTL by a coaxial circulator. The new installation includes cRio controls and a fast protection and monitoring system capable of reacting to faults within 10 µs. A new digital low-level RF (LLRF) system has been installed that integrates I/Q signal processing, PI feedback, and feedforward controls for beam loading compensation. Issues with LLRF stability were initially encountered due to interaction from thermal-related RF phase changes. After these issues were solved, the final outcome has been a reliable new RF system to complete the overall upgrade of the LANSCE DTL RF power plant.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA59  
About • Received ※ 03 August 2022 — Revised ※ 04 August 2022 — Accepted ※ 06 August 2022 — Issue date ※ 12 August 2022
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TUPA62 LANSCE Control System’s 50th Anniversary 482
 
  • M. Pieck, C.D. Hatch, J.O. Hill, H.A. Watkins, E.E. Westbrook
    LANL, Los Alamos, New Mexico, USA
 
  After almost exactly 50 years in service, the LANSCE (Los Alamos Neutron Science Center) control system has achieved a major milestone, replacing its original and reliable RICE (Remote Instrumentation and Control Equipment) with a modern customized control system. The task of replacing RICE was challenging because of its technology (late 1960’s), number of channels (>10,000), unique characteristics (all-modules data takes, timed/flavored data takes) and that it was designed as an integral part of the whole accelerator. We discuss the history, RICE integral architecture, upgrade efforts, and the new system providing cutting-edge capabilities. The boundary condition was that upgrades only could be implemented during the annual four-month accelerator maintenance outage. This led to a multi-phased project which turned out to be about an 11-year effort.  
poster icon Poster TUPA62 [1.985 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA62  
About • Received ※ 02 August 2022 — Revised ※ 09 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 25 September 2022
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TUPA64 Analysis of Resonant Converter Topology for High-Voltage Modulators 486
 
  • M. Sanchez Barrueta, J.T.M. Lyles, M.D.M. Morris
    LANL, Los Alamos, New Mexico, USA
 
  Funding: Work Supported by the United States Department of Energy, National Nuclear Security Agency, under contract DE-AC52-06NA25396
At the Los Alamos Neutron Science Center (LANSCE), we are considering various topologies to replace obsolete charging supplies and capacitor banks that provide high-voltage direct-current (DC) power to the 44, 805-MHz klystron modulators that drive the LANSCE Coupled Cavity Linac (CCL). Among the possible replacement topologies is the High Voltage Converter Modulator (HVCM), originally designed at LANSCE for use at the Spallation Neutron Source (SNS), to be used as a pulsed high-voltage power supply for klystron-based RF transmitters. The HVCM topology uses high frequency transformers with resonant LC networks for efficient energy conversion and a frequency dependent gain, which permits the use of frequency modulation as a control variable to afford pulse flattening and excellent regulation as demonstrated at SNS. A mathematical analysis is presented that links the converter resonant tank components to the frequency dependent output behavior of the converter modulator.
LA-UR-22-25179
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA64  
About • Received ※ 03 August 2022 — Revised ※ 10 August 2022 — Accepted ※ 12 August 2022 — Issue date ※ 22 August 2022
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TUPA65 Machine Learning for the LANL Electromagnetic Isotope Separator 490
 
  • A. Scheinker, K.W. Dudeck, C.P. Leibman
    LANL, Los Alamos, New Mexico, USA
 
  Funding: Los Alamos National Laboratory Electromagnetic Isotope Separator Project.
The Los Alamos National Laboratory electromagnetic isotope separator (EMIS) utilizes a Freeman ion source to generate beams of various elements which are accelerated to 40 keV and passed through a 75-degree bend using a large dipole magnet with a radius of 1.2 m. The isotope mass differences translate directly to a spread in momentum, dp, relative to the design momentum p0. Momentum spread is converted to spread in the horizontal arrival location dx at a target chamber by the dispersion of the dipole magnet: dx = D(s)dp/p0. By placing a thin slit leading to a collection chamber at a location xc specific isotope mass is isolated by adjusting the dipole magnet strength or the beam energy. The arriving beam current at xc is associated with average isotope atomic mass, giving an isotope mass spectrum I(m) measured in mA. Although the EMIS is a compact system (5 m) setting up and automatically running at an optimal isotope separation profile I(m) profile is challenging due to time-variation of the complex source as well as un-modeled disturbances. We present preliminary results of developing adaptive machine learning-based tools for the EMIS beam and for the accelerator components.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA65  
About • Received ※ 18 July 2022 — Revised ※ 07 August 2022 — Accepted ※ 08 August 2022 — Issue date ※ 10 August 2022
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TUPA69 Improving Cavity Phase Measurements at Los Alamos Neutron Science Center 493
 
  • P. Van Rooy, A.T. Archuleta, L.J. Castellano, S. Kwon, M.S. Prokop, P.A. Torrez
    LANL, Los Alamos, New Mexico, USA
 
  Control stability of the phase and amplitude in the cavity is a significant contributor to beam performance. The ability to measure phase and amplitude of pulsed RF systems at accuracies of ± 0.1 degrees and ± 0.1 percent required for our systems is difficult, and custom-designed circuitry is required. The digital low-level RF upgrade at the Los Alamos Neutron Science Center is continuing to progress with improved cavity phase measurements. The previous generation of the cavity phase and amplitude measurement system has a phase ambiguity, which requires repeated calibrations to ascertain the correct phase direction. The new phase measurement system removes the ambiguity and the need for field calibration while improving the range and precision of the cavity phase measurements. In addition, the new digital low-level RF systems is designed to upgrade the legacy system without significant mechanical, electrical, or cabling changes. Performance data for the new phase measurement system is presented.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA69  
About • Received ※ 02 August 2022 — Revised ※ 11 August 2022 — Accepted ※ 21 August 2022 — Issue date ※ 08 September 2022
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TUPA72 Comparison Study on First Bunch Compressor Schemes by Conventional and Double C-Chicane for MaRIE XFEL 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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TUPA73 Design and Low Power Test of an Electron Bunching Enhancer Using Electrostatic Potential Depression 499
 
  • H. Xu, B.E. Carlsten, Q.R. Marksteiner
    LANL, Los Alamos, New Mexico, USA
  • B.L. Beaudoin, T.W. Koeth, A. Ting
    UMD, College Park, Maryland, USA
 
  Funding: This project was supported by the U.S. Department of Energy Office of Science through the Accelerator Stewardship Program.
We present our experimental design and low power test results of a structure for the proof-of-principle demonstration of fast increase of the first harmonic current content in a bunched electron beam, using the technique of electrostatic potential depression (EPD). A primarily bunched electron beam from an inductive output tube (IOT) at 710 MHz first enters an idler cavity, where the longitudinal slope of the beam energy distribution is reversed. The beam then transits through an EPD section implemented by a short beam pipe with a negative high voltage bias, inside which the rate of increase of the first harmonic current is significantly enhanced. An output cavity measures the harmonic current developed inside the beam downstream of the EPD section. Low power test results of the idler and the output cavities agree with the theoretical design.
 
poster icon Poster TUPA73 [1.307 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA73  
About • Received ※ 29 July 2022 — Accepted ※ 03 August 2022 — Issue date ※ 09 August 2022  
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TUPA74 Numerical Calculations of Wave Generation from a Bunched Electron Beam in Space 502
 
  • H. Xu, G.L. Delzanno, L.D. Duffy, Q.R. Marksteiner, G.D. Reeves
    LANL, Los Alamos, New Mexico, USA
 
  Funding: This project was supported by the Laboratory Directed Research and Development program of Los Alamos National Laboratory.
We present our numerical approach and preliminary results of the calculations of whistler and X-mode wave generation by a bunched electron beam in space. The artificial generation of whistler and X-mode plasma waves in space is among the candidate techniques to accomplish the radiation belt remediation (RBR), in an effort to precipitate energetic electrons towards the atmosphere to reduce their threat to low-Earth orbit satellites. Free-space propagation of an electron pulse in a constant background magnetic field was simulated with the CST particle-in-cell (PIC) solver, with the temporal evolution of the beam recorded. The SpectralPlasmaSolver (SPS) was then modified to use the recorded electron pulse propagation to calculate the real-time plasma waves generated by the beam. SPS simulation results of the wave generation for the upcoming Beam-PIE experiment as well as an ideal bunched electron beam are shown.
 
poster icon Poster TUPA74 [0.963 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA74  
About • Received ※ 18 July 2022 — Revised ※ 02 August 2022 — Accepted ※ 07 August 2022 — Issue date ※ 08 August 2022
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TUPA75 High Gradient Testing Results of the Benchmark a/λ=0.105 Cavity at CERF-NM 505
 
  • M.R.A. Zuboraj, D.V. Gorelov, T.W. Hall, M.E. Middendorf, D. Rai, E.I. Simakov, T. Tajima
    LANL, Los Alamos, New Mexico, USA
 
  Funding: This work was supported by Los Alamos National Laboratory’s Laboratory Directed Research and Development (LDRD) Program.
This presentation will report initial results of high gradient testing of two C-band accelerating cavities fabricated at Los Alamos National Laboratory (LANL). At LANL, we commissioned a C-band Engineering Research Facility of New Mexico (CERF-NM) which has unique capability of conditioning and testing accelerating cavities for operation at surface electric fields at the excess of 300 MV/m, powered by a 50 MW, 5.712 GHz Canon klystron. Recently, we fabricated and tested two benchmark copper cavities at CERF-NM. These cavities establish a benchmark for high gradient performance at C-band and the same geometry will be used to provide direct comparison between high gradient performance of cavities fabricated of different alloys and by different fabrication methods. The cavities consist of three cells with one high gradient central cell and two coupling cells on the sides. The ratio of the radius of the coupling iris to the wavelength is a/λ=0.105. This poster will report high gradient test results such as breakdown rates as function of peak surface electric and magnetic fields and pulse heating.
 
poster icon Poster TUPA75 [0.890 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA75  
About • Received ※ 05 August 2022 — Revised ※ 11 August 2022 — Accepted ※ 12 August 2022 — Issue date ※ 01 October 2022
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TUPA77 X-Band Harmonic Longitudinal Phase Space Linearization at the PEGASUS Photoinjector 508
 
  • P.E. Denham, P. Musumeci, A. Ody
    UCLA, Los Angeles, USA
 
  Due to the finite bunch length, photoemitted electron beams sample RF-nonlinearities that lead to energy-time correlations along the bunch temporal profile. This is an important effect for all applications where the projected energy spread is important. In particular, for time-resolved single shot electron microscopy, it is critical to keep the beam energy spread below 1·10-4 to avoid chromatic aberrations in the lenses. Higher harmonic RF cavities can be used to compensate for the RF-induced longitudinal phase space nonlinearities. Start-to-end simulations suggest that this type of compensation can reduce energy spread to the 1·10-5 level. This work is an experimental study of x-band harmonic linearization of a beam longitudinal phase space at the PEGASUS facility, including developing high-resolution spectrometer diagnostics to verify the scheme.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA77  
About • Received ※ 25 July 2022 — Revised ※ 04 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 10 August 2022
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TUPA80 Cyborg Beamline Development Updates 512
 
  • G.E. Lawler, A. Fukasawa, N. Majernik, J.R. Parsons, J.B. Rosenzweig, Y. Sakai
    UCLA, Los Angeles, California, USA
  • F. Bosco
    Sapienza University of Rome, Rome, Italy
  • Z. Li, S.G. Tantawi
    SLAC, Menlo Park, California, USA
  • B. Spataro
    LNF-INFN, Frascati, Italy
 
  Funding: This work was supported by the Center for Bright Beams, National Science Foundation Grant No. PHY-1549132 and DOE Contract DE-SC0020409.
Xray free electron laser (XFEL) facilities in their current form are large, costly to maintain, and inaccessible due to their minimal supply and high demand. It is then advantageous to consider miniaturizing XFELs through a variety of means. We hope to increase beam brightness from the photoinjector via high gradient operation (>120 MV/m) and cryogenic temperature operation at the cathode (<77K). To this end we have designed and fabricated our new CrYogenic Brightness-Optimized Radiofrequency Gun (CYBGORG). The photogun is 0.5 cell so much less complicated than our eventual 1.6 cell photoinjector. It will serve as a prototype and test bed for cathode studies in a new cryogenic and very high gradient regime. We present here the fabricated structure, progress towards commissioning, and beamline simulations.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA80  
About • Received ※ 02 August 2022 — Accepted ※ 06 August 2022 — Issue date ※ 09 October 2022  
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TUPA81 Design of a High-Power RF Breakdown Test for a Cryocooled C-Band Copper Structure 516
 
  • G.E. Lawler, A. Fukasawa, J.R. Parsons, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
  • Z. Li, S.G. Tantawi
    SLAC, Menlo Park, California, USA
  • A. Mostacci
    Sapienza University of Rome, Rome, Italy
  • E.I. Simakov, T. Tajima
    LANL, Los Alamos, New Mexico, USA
  • B. Spataro
    LNF-INFN, Frascati, Italy
 
  Funding: This work was supported by the DOE Contract DE-SC0020409.
High-gradient RF structures capable of maintaining gradients in excess of 250 MV/m are critical in several concepts for future electron accelerators. Concepts such as the ultra-compact free electron laser (UC-XFEL) and the Cool Copper Collider (C3) plan to obtain these gradients through the cryogenic operation (<77K) of normal conducting copper cavities. Breakdown rates, the most significant gradient limitation, are significantly reduced at these low temperatures, but the precise physics is complex and involves many interacting effects. High-power RF breakdown measurements at cryogenic temperatures are needed at the less explored C-band frequency (5.712 GHz), which is of great interest for the aforementioned concepts. On behalf of a large collaboration of UCLA, SLAC, LANL, and INFN, the first C-band cryogenic breakdown measurements will be made using a LANL RF test infrastructure. The 2-cell geometry designed for testing will be modifications of the distributed coupled reentrant design used to efficiently power the cells while staying below the limiting values of peak surface electric and magnetic fields.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA81  
About • Received ※ 29 July 2022 — Accepted ※ 02 August 2022 — Issue date ※ 08 August 2022  
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TUPA82 Transverse Stability in an Alternating Symmetry Planar Dielectric Wakefield Structure 519
 
  • W.J. Lynn, G. Andonian, N. Majernik, S.M. OTool, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
  • D.S. Doran, S.Y. Kim, J.F. Power, E.E. Wisniewski
    ANL, Lemont, Illinois, USA
  • P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
 
  Funding: DE-SC0017648 - AWA.
Dielectric Wakefield Acceleration (DWA) is a promising technique for realizing the next generation of linear colliders. It provides access to significantly higher accelerating gradients than traditional radio-frequency cavities. One impediment to realizing a DWA-powered accelerator is the issue of the transverse stability of the beams within the dielectric structure due to short-range wakefields. These short-range wakefields have a tendency to induce a phenomenon known as single-bunch beam breakup, which acts as its name implies and destroys the relevant beam. We attempt to solve this issue by leveraging the quadrupole mode excited in a planar dielectric structure and then alternating the orientation of said structure to turn an unstable system into a stable one. We examine this issue computationally to determine the limits of stability and based on those simulations describe a future experimental realization of this strategy.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA82  
About • Received ※ 02 August 2022 — Revised ※ 11 August 2022 — Accepted ※ 12 August 2022 — Issue date ※ 30 September 2022
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TUPA83 Derivative-Free Optimization of Multipole Fits to Experimental Wakefield Data 523
 
  • N. Majernik, G. Andonian, W.J. Lynn, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
  • P. Piot, T. Xu
    Northern Illinois University, DeKalb, Illinois, USA
 
  Funding: Department of Energy DE-SC0017648.
A method to deduce the transverse self-wakefields acting on a beam, based only on screen images, is introduced. By employing derivative-free optimization, the relatively high-dimensional parameter space can be efficiently explored to determine the multipole components up to the desired order. This technique complements simulations, which are able to directly infer the wakefield composition. It is applied to representative simulation results as a benchmark and also applied to experimental data on skew wake observations from dielectric slab structures.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA83  
About • Received ※ 02 August 2022 — Revised ※ 21 August 2022 — Accepted ※ 26 August 2022 — Issue date ※ 11 September 2022
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TUPA84 Reconstructing Beam Parameters from Betatron Radiation Through Machine Learning and Maximum Likelihood Estimation 527
 
  • S. Zhang, N. Majernikpresenter, B. Naranjo, J.B. Rosenzweig, M. Yadav
    UCLA, Los Angeles, California, USA
  • Ö. Apsimon, C.P. Welsch, M. Yadav
    The University of Liverpool, Liverpool, United Kingdom
 
  Funding: US Department of Energy, Division of High Energy Physics, under Contract No. DE-SC0009914.
The dense drive beam used in plasma wakefield acceleration generates a linear focusing force that causes electrons inside the witness beam to undergo betatron oscillations, giving rise to betatron radiation. Because information about the properties of the beam is encoded in the betatron radiation, measurements of the radiation such as those recorded by the UCLA-built Compton spectrometer can be used to reconstruct beam parameters. Two possible methods of extracting information about beam parameters from measurements of radiation are machine learning (ML), which is increasingly being implemented for different fields of beam diagnostics, and a statistical technique known as maximum likelihood estimation (MLE). We assess the ability of both machine learning and MLE methods to accurately extract beam parameters from measurements of betatron radiation.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA84  
About • Received ※ 02 August 2022 — Revised ※ 07 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 05 October 2022
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TUPA85 First Results from a Multileaf Collimator and Emittance Exchange Beamline 531
 
  • N. Majernik, G. Andonian, C.D. Lorch, W.J. Lynn, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
  • D.S. Doran, S.Y. Kim, P. Piot, J.G. Power, C. Whiteford, E.E. Wisniewski
    ANL, Lemont, Illinois, USA
 
  Funding: Department of Energy DE-SC0017648 and National Science Foundation PHY-1549132.
By shaping the transverse profile of a particle beam prior to an emittance exchange (EEX) beamline, drive and witness beams with variable current profiles and bunch spacing can be produced. Presently at AWA, this transverse shaping is accomplished with individually laser-cut tungsten masks, making the refinement of beam profiles a slow process. In contrast, a multileaf collimator (MLC) is a device that can selectively mask the profile of a beam using many independently actuated leaves. Since an MLC permits real-time adjustment of the beam shape, its use as a beam mask would permit much faster optimization in a manner highly synergistic with machine learning. Beam dynamics simulations have shown that such an approach is functionally equivalent to that offered by the laser cut masks. In this work, the construction and first results from a 40-leaf, UHV compatible MLC are discussed.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA85  
About • Received ※ 16 July 2022 — Revised ※ 02 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 12 August 2022
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TUPA86 Simulations of Nanoblade Cathode Emissions with Image Charge Trapping for Yield and Brightness Analyses 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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TUPA87 Simulations for the Space Plasma Experiments at the SAMURAI Lab 539
 
  • P. Manwani, H.S. Ancelin, A. Fukasawa, G.E. Lawler, N. Majernikpresenter, B. Naranjo, J.B. Rosenzweig, Y. Sakai, O. Williams
    UCLA, Los Angeles, California, USA
  • G. Andonian
    RadiaBeam, Santa Monica, California, USA
 
  Funding: This work was performed with support of the US Department of Energy under Contract No. DE-SC0017648 and DESC0009914, and the DARPA GRIT Contract 20204571
Plasma wakefield acceleration using the electron linear accelerator test facility, SAMURAI, can be used to study the Jovian electron spectrum due to the high energy spread of the beam after the plasma interaction. The SAMURAI RF facility which is currently being constructed and commissioned at UCLA, is is capable of producing beams with 10 MeV energy, 2 nC charge, and 200 fsec bunch lengths with a 4 um emittance. Particle-in-cell (PIC) simulations are used to study the beam spectrum that would be generated from plasma interaction. Experimental methods and diagnostics are discussed in this paper.
 
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA87  
About • Received ※ 04 August 2022 — Revised ※ 08 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 06 September 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)