Keyword: GUI
Paper Title Other Keywords Page
MOZD2 Preliminary Study of a High Gain THz FEL in a Recirculating Cavity electron, radiation, undulator, FEL 30
  • A.C. Fisher, P. Musumeci
    UCLA, Los Angeles, California, USA
  The THz gap is a region of the electromagnetic spectrum where high average and peak power radiation sources are scarce while at the same time scientific and industrial applications are growing in demand. Free-electron laser coupling in a magnetic undulator is one of the best options for radiation generation in this frequency range, but slippage effects require the use of relatively long and low current electron bunches to drive the THz FEL, limiting amplification gain and output peak power. Here we use a circular waveguide in a 0.96 m strongly tapered helical undulator to match the radiation and e-beam velocities, allowing resonant energy extraction from an ultrashort 200 pC 5.5 MeV electron beam over an extended distance. E-beam energy measurements, supported by energy and spectral measurement of the THz FEL radiation, indicate an average energy efficiency of ~ 10%, with some particles losing > 20% of their initial kinetic energy.  
slides icon Slides MOZD2 [7.005 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOZD2  
About • Received ※ 04 August 2022 — Revised ※ 04 August 2022 — Accepted ※ 06 August 2022 — Issue date ※ 13 August 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
MOPA62 High Quality Conformal Coatings on Accelerator Components via Novel Radial Magnetron with High-Power Impulse Magnetron Sputtering niobium, target, plasma, SRF 182
  • W.M. Huber, I. Haehnlein, T.J. Houlahan, B.E. Jurczyk, A.S. Morrice, R.A. Stubbers
    Starfire Industries LLC, Champaign, USA
  Funding: This material is based upon work supported by the U.S. Department of Energy under Award Numbers DE-SC0019784 and DE-SC0020481.
In this work, we present two configurations of a novel radial magnetron design that are suitable for coating the complex inner surfaces of a variety of modern particle accelerator components. These devices have been used in conjunction with high-power impulse magnetron sputtering (HiPIMS) to deposit copper and niobium films onto the inner surfaces of bellows assemblies, waveguides, and SRF cavities. These films, with thicknesses of up to 3 µm and 40 µm for niobium and copper, respectively, have been shown to be conformal, adherent, and conductive. In the case of copper, the post-bake RRR values of the resulting films are well within the range specified for electroplating of the LCLS-II bellows and CEBAF waveguide assemblies. In addition to requiring no chemical processing beyond a detergent rinse and solvent degrease, this magnetron design exhibits over 80% target material utilization. Further, in the case of niobium, an enhancement in RRR over that of the bulk (target) material has been observed.
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA62  
About • Received ※ 02 August 2022 — Revised ※ 05 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 21 August 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
MOPA74 Design of a W-Band Corrugated Waveguide for Structure Wakefield Acceleration wakefield, electron, acceleration, accelerating-gradient 210
  • B. Leung, X. Lu, C.L. Phillips, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
  • D.S. Doran, X. Lu, P. Piot, J.G. Power
    ANL, Lemont, Illinois, USA
  Current research on structure wakefield acceleration aims to develop radio-frequency structures that can produce high gradients, with work in the sub-terahertz regime being particularly interesting because of the potential to create more compact and economical accelerators. Metallic corrugated waveguides at sub-terahertz frequencies are one such structure. We have designed a W-band corrugated waveguide for a collinear wakefield acceleration experiment at the Argonne Wakefield Accelerator (AWA). Using the CST Studio Suite, we have optimized the structure for the maximum achievable gradient in the wakefield from a nominal AWA electron bunch at 65 MeV. Simulation results from different solvers of CST were benchmarked with each other, with analytical models, and with another simulation code, ECHO. We are investigating the mechanical design, suitable fabrication technologies, and the possibility to apply advanced bunch shaping techniques to improve the structure performance.  
poster icon Poster MOPA74 [1.518 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA74  
About • Received ※ 30 July 2022 — Revised ※ 03 August 2022 — Accepted ※ 07 August 2022 — Issue date ※ 26 August 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
MOPA76 Wakefield Modeling in Sub-THz Dielectric-Lined Waveguides wakefield, simulation, electron, experiment 218
  • C.L. Phillips, B. Leung, X. Lu, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
  Dielectric-lined waveguides have been extensively studied to potentially support high-gradient acceleration in beam-driven dielectric wakefield acceleration (DWFA) and for beam manipulations. In this paper, we investigate the wakefield generated by a relativistic bunch passing through a dielectric waveguide with different transverse sections. We specifically consider the case of a structure consisting of two dielectric slabs, along with rectangular and square structures. Numerical simulations performed with the fine-difference time-domain of the WarpX program reveal some interesting features of the transverse wake and a possible experiment at the Argonne Wakefield Accelerator (AWA) is proposed.  
poster icon Poster MOPA76 [1.294 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA76  
About • Received ※ 12 August 2022 — Accepted ※ 13 August 2022 — Issue date ※ 12 September 2022  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPA13 Affordable, Efficient Injection-Locked Magnetrons for Superconducting Cavities cavity, injection, electron, controls 366
  • M. Popovic, M.A. Cummings, R.P. Johnson, S.A. Kahn, 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
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPA15 Development of a CVD System for Next-Generation SRF Cavities cavity, controls, SRF, vacuum 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
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPA16 Singularity-Free Exact Dipole Bend Transport Equations dipole, simulation, lattice, framework 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
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPA69 Improving Cavity Phase Measurements at Los Alamos Neutron Science Center cavity, LLRF, controls, neutron 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
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPA75 High Gradient Testing Results of the Benchmark a/λ=0.105 Cavity at CERF-NM cavity, klystron, coupling, MMI 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
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPA81 Design of a High-Power RF Breakdown Test for a Cryocooled C-Band Copper Structure cavity, cryogenics, distributed, electron 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  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
WEPA26 197 MHz Waveguide Loaded Crabbing Cavity Design for the Electron-Ion Collider cavity, HOM, impedance, electron 679
  • S.U. De Silva, J.R. Delayen
    ODU, Norfolk, Virginia, USA
  • J. Guo, R.A. Rimmer
    JLab, Newport News, Virginia, USA
  • Z. Li
    SLAC, Menlo Park, California, USA
  • B.P. Xiao
    BNL, Upton, New York, USA
  The Electron-Ion Collider will require crabbing systems at both hadron and electron storage rings in order to reach the desired luminosity goal. The 197 MHz crab cavity system is one of the critical rf systems of the col-lider. The crab cavity, based on the rf-dipole design, ex-plores the option of waveguide load damping to suppress the higher order modes and meet the tight impedance specifications. The cavity is designed with compact dog-bone waveguides with transitions to rectangular wave-guides and waveguide loads. This paper presents the compact 197 MHz crab cavity design with waveguide damping and other ancillaries.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA26  
About • Received ※ 08 August 2022 — Revised ※ 09 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 06 September 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
WEPA53 An Open Radiofrequency Accelerating Structure coupling, gun, impedance, SRF 753
  • S.V. Kuzikov
    Euclid TechLabs, Solon, Ohio, USA
  We report an open multi-cell accelerating structure. Being integrated with a set of open-end waveguides, this structure can suppress high-order modes (HOMs). All the accelerating cells are connected at the side to rectangular cross-section waveguides which strongly coupled with free space or absorbers. Due to the anti-phased contribution of the cell pairs, the operating mode does not leak out, and has as high-quality factor as for a closed accelerating structure. However, the compensation does not occur for spurious high-order modes. This operating principle also allows for strong coupling between the cells of the structure, which is why high homogeneity of the accelerating fields can be provided along the structure. We discuss the obtained simulation results and possible applications. Its include a normal conducting high-shunt impedance accelerator, a tunable photoinjector’s RF gun, and a high-current, high-selective SRF accelerators.  
poster icon Poster WEPA53 [1.817 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA53  
About • Received ※ 01 August 2022 — Revised ※ 08 August 2022 — Accepted ※ 12 August 2022 — Issue date ※ 16 August 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
WEPA64 Design and Commissioning of the ASU CXLS Machine Protection System controls, klystron, detector, machine-protect 770
  • S.P. Jachim, B.J. Cook, J.R.S. Falconer, A.J. Gardeck, W.S. Graves, M.R. Holl, R.S. Rednour, D.M. Smith, J.V. Vela
    Arizona State University, Tempe, USA
  Funding: This work was supported in part by NSF award #1935994.
To protect against fault conditions in the high-power RF transport and accelerating structures of the Arizona State University (ASU) Compact X-Ray Light Source (CXLS), the Machine Protection System (MPS) extinguishes the 6.5-MW RF energy sources within approximately 50 ns of the fault event. In addition, each fault is localized and reported remotely via USB for operational and maintenance purposes. This paper outlines the requirements, design, and performance of the MPS applied on the CXLS.
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA64  
About • Received ※ 13 July 2022 — Revised ※ 28 July 2022 — Accepted ※ 08 August 2022 — Issue date ※ 12 August 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
WEPA65 On-Chip Photonics Integrated Photocathodes electron, photon, cathode, coupling 773
  • A.H. Kachwala, O. Chubenko, S.S. Karkare
    Arizona State University, Tempe, USA
  • R. Ahsan
    USC, Los Angeles, California, USA
  • H.U. Chae, R. Kapadia
    University of Southern California, Los Angeles, California, USA
  Funding: This work is supported by the NSF Center for Bright Beams under award PHY-1549132, and by the Department of Energy, Office of Science under awards DE-SC0021092, and DE-SC0021213.
Photonics integrated photocathodes can result in advanced electron sources for various accelerator applications. In such photocathodes, light can be directed using waveguides and other photonic components on the substrate underneath a photoemissive film to generate electron emission from specific locations at sub-micron scales and at specific times at 100-femtosecond scales along with triggering novel photoemission mechanisms resulting in brighter electron beams and enabling unprecedented spatio-temporal shaping of the emitted electrons. In this work we have demonstrated photoemission confined in the transverse direction using a nanofabricated Si3N4 waveguide underneath a 40-nm thick cesiated GaAs photoemissive film, thus demonstrating a proof of principle feasibility of such photonics integrated photocathodes. This work paves the way to integrate the advances in the field of photonics and nanofabrication with photocathodes to develop better electron sources.
poster icon Poster WEPA65 [0.642 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA65  
About • Received ※ 26 July 2022 — Revised ※ 06 August 2022 — Accepted ※ 07 August 2022 — Issue date ※ 10 August 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)