NAPAC2019 - List of Keywords (MMI)

Paper	Title	Other Keywords	Page
MOYBA2	Commissioning of the Phase 2 and Phase 3 SuperKEKB / B-Factory	detector, luminosity, optics, injection	14
	S. Nakamura KEK, Ibaraki, Japan
	The next generation of B-Factory, the SuperKEKB electron-positron collider at KEK (Japan) has started after two years shutdown from the Phase 1 commissioning in 2016. The first phase for the vacuum scrubbing in 2016 and the second phase focused on the verification of the novel "nano-beam" collision scheme were successfully completed in 2018. The modifications between Phase 1 and Phase 2 follows Phase 3 are installations of the final focus system and the Belle II detector. In order to accomplish the higher luminosity more than the predecessor KEKB , the nano-beam scheme is studied with higher bunch currents to reduce the beam-beam blowup which degrade the luminosity. The new collision scheme is reviewed and the luminosity performance and overall status in the Phase 2 and Phase 3 commissioning are presented.
	Slides MOYBA2 [13.453 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOYBA2
About •	paper received ※ 30 August 2019 paper accepted ※ 01 September 2019 issue date ※ 08 October 2019
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MOYBA6	Accelerator Performance During the Beam Energy Scan II at RHIC in 2019	electron, operation, luminosity, cavity	26
	C. Liu, I. Blacker, M. Blaskiewicz, K.A. Brown, D. Bruno, K.A. Drees, A.V. Fedotov, W. Fischer, C.J. Gardner, C.E. Giorgio, X. Gu, T. Hayes, H. Huang, R.L. Hulsart, D. Kayran, N.A. Kling, Y. Luo, D. Maffei, G.J. Marr, B. Martin, A. Marusic, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, C. Naylor, S. Nemesure, I. Pinayev, S. Polizzo, V.H. Ranjbar, D. Raparia, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, F. Severino, T.C. Shrey, K.S. Smith, S. Tepikian, P. Thieberger, A. Zaltsman, K. Zeno, I.Y. Zhang, W. Zhang BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. RHIC provided Au-Au collisions at beam energies of 9.8, 7.3, 4.59 and 3.85 GeV/nucleon during the first year of the Beam Energy Scan II in 2019. The physics goals at the first two higher beam energies were achieved. At the two lower beam energies, bunched electron beam cooling has been demonstrated successfully. The accelerator performance was improved compared to when RHIC was operated at these energies in earlier years. This article will introduce the challenges to operate RHIC at low energies and the corresponding countermeasures, and review the improvement of accelerator performance during the operation in 2019.
	Slides MOYBA6 [6.579 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOYBA6
About •	paper received ※ 21 August 2019 paper accepted ※ 06 September 2019 issue date ※ 08 October 2019
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MOZBA5	Optimized Linear and Second Order Chromaticity Setpoints for the Advanced Photon Source Upgrade	lattice, sextupole, simulation, photon	70
	Y.P. Sun 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 nominal single particle dynamics optimizations of the Advanced Photon Source upgrade (APS-U) lattice are performed with dense numerical simulations of local momentum acceptance and dynamic acceptance. These simulations are quite time consuming, which may take weeks for optimizing one setpoint of linear chromaticity. In this paper, an alternative optimization method is adopted to generate optimized linear and second order chromaticity setpoints for the Advanced Photon Source upgrade lattice. This method is efficient in computing time needed, which is capable to generate a grid of optimized chromaticity setpoints in a relatively short time. The performance of these lattice solutions are verified by simulations with reasonable errors. These lattice solutions with different linear (or second order) chromaticity may be useful for the future APS-U commissioning and operations.
	Slides MOZBA5 [3.350 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOZBA5
About •	paper received ※ 31 August 2019 paper accepted ※ 02 September 2019 issue date ※ 08 October 2019
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MOPLM24	LCLS-II Injector Commissioning Beam Based Measurements	electron, gun, laser, cathode	157
	C.M. Zimmer, T.J. Maxwell, F. Zhou SLAC, Menlo Park, California, USA
	Funding: Department of Energy Injector commissioning is underway for the LCLS-II MHz repetition rate FEL, currently under construction at SLAC. Methodology of injector beam-based measurements and early results with low beam charge will be presented, along with the software tools written to automate these various measurements.
	Poster MOPLM24 [10.104 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOPLM24
About •	paper received ※ 28 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019
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MOPLO17	Large-Scale Dewar Testing of FRIB Production Cavities: Results	cavity, cryomodule, SRF, linac	270
	W. Hartung, W. Chang, S.H. Kim, D. Norton, J.T. Popielarski, K. Saito, J.F. Schwartz, T. Xu, C. Zhang FRIB, East Lansing, Michigan, USA
	The Facility for Rare Isotope Beams (FRIB), under construction at Michigan State University (MSU), includes a superconducting driver linac to deliver ion beams at 200 MeV per nucleon. The driver linac requires 10⁴ quarter-wave resonators (QWRs, β = 0.041 and 0.085) and 220 half-wave resonators (HWRs, β = 0.29 and 0.54). The jacketed resonators are Dewar tested at MSU before installation into cryomodules. The cryomodules for β = 0.041, 0.085, and 0.29 have been completed and certified; 89% of the β = 0.54 HWRs have been certified (as of May 2019). The Dewar certification tests have provided valuable information on the performance of production QWRs and HWRs at 4.3 K and 2 K and on performance limits. Results will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOPLO17
About •	paper received ※ 08 November 2019 paper accepted ※ 26 November 2019 issue date ※ 08 October 2019
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TUPLH20	Commissioning of the CESR Upgrade for CHESS-U	HOM, wiggler, impedance, storage-ring	522
	J.P. Shanks, G.W. Codner, M.J. Forster, D.L. Rubin, S. Wang, L. Ying Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: Funding for the CHESS-U upgrade provided by New York State Capital Grant #AA737 / CFA #53676 The Cornell Electron Storage Ring (CESR) was upgraded in the second half of 2018 to become a dedicated synchrotron light source, CHESS-U. The upgrade is by far the largest modification to CESR in its 40-year history, replacing one-sixth of the storage ring with six new double-bend achromats, increasing beam energy from 5.3 GeV to 6.0 GeV, and switching from two counter-rotating beams to a single on-axis positron beam. The new achromats include combined-function dipoles, a first in CESR, and reduce the horizontal emittance by a factor of four. Eight compact narrow-gap undulators (4.6mm vacuum chamber aperture) and one high-energy 24-pole wiggler feed a total of six new and five existing x-ray end stations from a single positron beam. Commissioning of CHESS-U took place in the first half of 2019. We report on the methods and results of beam commissioning, including initial beam accumulation, optics correction, characterization, and commissioning of compact permanent-magnet insertion devices.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLH20
About •	paper received ※ 26 August 2019 paper accepted ※ 02 September 2019 issue date ※ 08 October 2019
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TUPLE08	Commissioning Update on RF Station #5 of AWA	high-voltage, klystron, electron, cavity	580
	W. Liu, M.E. Conde, D.S. Doran, G. Ha, J.G. Power, J.H. Shao, C. Whiteford, E.E. Wisniewski ANL, Lemont, Illinois, USA C. Jing Euclid Beamlabs LLC, Bolingbrook, USA
	Funding: The US Department of Energy, Office of Science The RF system of Argonne Wakefield Accelerator (AWA) facility has grown over the years from one RF power station into 4 RF power stations. The demand for RF power keeps growing as the capability of AWA continues to grow. Now the 5th RF station is needed to fulfill the RF power needs of AWA facility. Some details regarding the construction and commissioning of the 5th RF station of AWA facility are documented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLE08
About •	paper received ※ 29 August 2019 paper accepted ※ 05 September 2019 issue date ※ 08 October 2019
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WEYBB1	ELENA Commissioning	electron, proton, experiment, antiproton	626
	D. Gamba, M.E. Angoletta, P. Belochitskii, L. Bojtár, F. Butin, C. Carli, B. Dupuy, Y. Dutheil, T. Eriksson, P. Freyermuth, C. Grech, M. Hori, J.R. Hunt, M. Jaussi, L.V. Jørgensen, B. Lefort, S. Pasinelli, L. Ponce, G. Tranquille CERN, Meyrin, Switzerland R. Gebel FZJ, Jülich, Germany C. Grech University of Malta, Information and Communication Technology, Msida, Malta M. Hori MPQ, Garching, Munich, Germany
	The Extra Low ENergy Antiproton storage ring (ELENA) is an upgrade project at the CERN AD (Antiproton Decelerator). ELENA will further decelerate the 5.3 MeV antiprotons coming from the AD down to 100 keV. ELENA features electron cooling for emittance control during deceleration thus preserving the beam intensity and allowing to extract bright bunches towards the experiments. The lower energy will allow for increasing the antiproton trapping efficiency up to two orders of magnitude, which is typically less than 1% with the present beam from AD. The ring was completed with the installation of the electron cooler at the beginning of 2018. Decelerated beams with characteristics close to the design values were obtained before the start of CERN Long Shutdown 2 (LS2). During LS2 electrostatic transfer lines from the ELENA ring to the experimental zones will be installed, replacing the magnetic transfer lines from the AD ring. The latest results of commissioning with H⁻ and antiprotons and the first observation of electron cooling in ELENA will be presented, together with an overview of the project and status and plans for LS2 and beyond.
	Slides WEYBB1 [20.792 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEYBB1
About •	paper received ※ 27 August 2019 paper accepted ※ 05 September 2019 issue date ※ 08 October 2019
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WEYBB4	Progress of Liquid Lithium Stripper for FRIB	operation, vacuum, electron, gun	636
	T. Kanemura, J. Gao, R. Madendorp, F. Marti, Y. Momozaki FRIB, East Lansing, Michigan, USA M.J. LaVere MSU, East Lansing, Michigan, USA Y. Momozaki ANL, Lemont, Illinois, USA
	Funding: This work is supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 The Facility for Rare Isotope Beams (FRIB) at Michigan State University is building a heavy ion linear accelerator (linac) to produce rare isotopes by the fragmentation method. At energies between 16 and 20 MeV/u ions are further stripped by a charge stripper increasing the energy gain downstream in the linac. The main challenges in the stripper design are high power deposited by the ions in the stripping media and radiation damage to the media itself. To overcome these challenges, self-recovering stripper media are the most suitable solutions. The FRIB baseline choice is a high-velocity thin film of liquid lithium. Because liquid lithium is highly reactive with air, we have implemented rigorous safety measures. Since May 2018, the lithium stripper system has been operated safely at an offline test site to accumulate operational experience. Recently, we successfully completed a 10-day long unattended continuous operation without any issue, which proved the reliability of the system. The next step is to characterize the lithium film stability with diagnostics. In 2020, we plan to bring the lithium stripper into the accelerator tunnel and commission it with ion beams. Jie Wei, et al., TU1A04, Proceedings of LINAC 2012, Tel-Aviv, Israel
	Slides WEYBB4 [6.012 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEYBB4
About •	paper received ※ 03 September 2019 paper accepted ※ 04 September 2019 issue date ※ 08 October 2019
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WEZBA2	Experience and Lessons in FRIB Superconducting Quarter-Wave Resonator Commissioning	cavity, cryomodule, linac, controls	646
	S.H. Kim, H. Ao, F. Casagrande, W. Chang, C. Compton, A. Facco, V. Ganni, E. Gutierrez, W. Hartung, N. Hasan, P. Knudsen, T.L. Larter, H. Maniar, S.J. Miller, D.G. Morris, P.N. Ostroumov, A.S. Plastun, J.T. Popielarski, L. Popielarski, H.T. Ren, K. Saito, M. Thrush, D.R. Victory, J. Wei, M. Xu, T. Xu, Y. Yamazaki, C. Zhang, S. Zhao FRIB, East Lansing, Michigan, USA
	The superconducting (SC) linear accelerator (linac) for the Facility for Rare Isotope Beams (FRIB) has one quarter-wave resonator (QWR) segment and two half-wave resonator (HWR) segments. The first linac segment (LS1) contains twelve β = 0.041 and ninety-two β = 0.085 QWRs operating at 80.5 MHz, and thirty-nine SC solenoids. Superconducting radiofrequency (SRF) commissioning and beam commissioning of LS1 was completed in April 2019. The design accelerating gradients (5.1 MV/m for β = 0.041 and 5.6 MV/m for β = 0.085) were achieved in all cavities with no multipacting or field emission issues. The cavity field met the design goals: peak-to-peak stability of ±1% in amplitude and ±1° in phase. We achieved 20.3 MeV/u ion beams of Ar, Kr, Ne, and Xe with LS1. In this paper, we will discuss lessons learned from the SRF commissioning of the cryomodules and methods developed for efficient testing, conditioning, and commissioning of more than 100 SC cavities, each with its own independent RF system.
	Slides WEZBA2 [2.841 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEZBA2
About •	paper received ※ 03 September 2019 paper accepted ※ 05 December 2019 issue date ※ 08 October 2019
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WEPLM03	The LLRF Control Design and Validation at FRIB	LLRF, controls, cavity, cryomodule	667
	S. Zhao, W. Chang, S.H. Kim, H. Maniar, D.G. Morris, P.N. Ostroumov, J.T. Popielarski, H.T. Ren, N.R. Usher FRIB, East Lansing, Michigan, USA N.R. Usher Ionetix, Lansing, Michigan, USA
	Funding: This work is supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661. One of the challenges in designing the low level radio frequency (LLRF) controllers for the Facility for Rare Isotope Beams (FRIB) is the various types of cavities, which include 5 different frequencies ranging from 40.25 MHz up to 322 MHz, and 4 different types of tuners. In this paper, the design strategy taken to achieve flexibility and low cost and the choices made to accommodate the varieties will be discussed. The approach also allowed easy adaptation to major design changes such as replac-ing two cryo-modules with two newly designed room temperature bunchers and the addition of high-voltage bias to suppress multi-pacting in half wave resonators (HWRs). With the successful completion of the third accelerator readiness review (ARR03) commissioning in early 2019, most of the design has been validated in the real accelerator system, leaving only HWRs which are constantly undergoing tests in cryo-module bunker. The integrated spark detector design for HWRs will also be tested in the near future.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM03
About •	paper received ※ 31 August 2019 paper accepted ※ 05 September 2019 issue date ※ 08 October 2019
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WEPLM63	Development of a Secondary Sn Source for Nb₃Sn Coating of Half-Wave Coaxial Resonator	cavity, niobium, SRF, superconductivity	735
	J.K. Tiskumara, J.R. Delayen, H. Park ODU, Norfolk, Virginia, USA G.V. Eremeev JLab, Newport News, Virginia, USA U. Pudasaini The College of William and Mary, Williamsburg, Virginia, USA
	Superconducting thin films have the potential of reducing the cost of particle accelerators. Among the potential materials, Nb₃Sn has a higher critical temperature and higher critical field compared to niobium. Sn vapor diffusion method is the preferred technique to coat niobium cavities. Although there are several thin-film-coated basic cavity models that are tested at their specific frequencies, the Half-wave resonator could provide us data across frequencies of interest for particle accelerators. With its advanced geometry, increased area, increased number of ports and hard to reach areas, the half-wave resonator needs a different coating approach, in particular, a development of a secondary Sn source. We are commissioning a secondary Sn source in the coating system and expand the current coating system at JLab to coat complex cavity models.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM63
About •	paper received ※ 27 August 2019 paper accepted ※ 06 September 2019 issue date ※ 08 October 2019
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WEPLM70	FRIB Tuner Performance and Improvement	cavity, linac, cryomodule, controls	755
	J.T. Popielarski, W. Chang, C. Compton, W. Hartung, S.H. Kim, E.S. Metzgar, S.J. Miller, K. Saito, J.F. Schwartz, T. Xu FRIB, East Lansing, Michigan, USA
	Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 The Facility for Rare Isotope Beams (FRIB) is under construction at Michigan State University (MSU). The FRIB superconducting driver linac will accelerate ion beams to 200 MeV per nucleon. The driver linac requires 10⁴ quarter-wave resonators (QWRs, β = 0.041 and 0.085) and 220 half-wave resonators (HWRs, β = 0.29 and 0.54). The cryomodules for β = 0.041, 0.085, and 0.29 have been completed and certified; 32 out of 49 cryomodules are certified via bunker test (as of March 2019). FRIB QWR cavities have a demountable niobium tuning plate which uses a warm external stepper motor and the FRIB HWR cavities use pneumatic actuated bellows. Progress on the preparation and performance of the tuners is presented in this paper along with improvements made to ensure meeting frequency specification.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM70
About •	paper received ※ 26 September 2019 paper accepted ※ 19 November 2019 issue date ※ 08 October 2019
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WEPLS04	Simulations of Low Energy Au⁷⁸⁺ Losses in RHIC	electron, lattice, optics, closed-orbit	775
	G. Robert-Demolaize, K.A. Drees, Y. Luo BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The RHIC Run19 BES-II program features the commissioning of the Low Energy RHIC electron Cooling (LEReC) Project, which uses electron cooling techniques to compensate for intra-beam scattering and thus to improve the luminosity lifetime. During RHIC operations at 3.85 GeV (beam energy) with LEReC, one needs to ensure that the electron beam energy is properly matched for cooling purposes: if so, some of the circulating Au-79 ions can recombine with an electron, turning into Au-78 and circulating with a large momentum offset. Part of the LEReC commissioning steps is therefore to drive a maximized number of Au-78 ions towards a chosen location of the RHIC mechanical aperture to generate particle showers that can be detected by a Recombination Monitor outside the cryostat. This article introduces the baseline lattice design, then discusses the few scenarios considered for optimizing Au-78 losses at a given location. Each scenario is then simulated using new tracking tools for generating beam loss maps.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLS04
About •	paper received ※ 27 August 2019 paper accepted ※ 03 September 2019 issue date ※ 08 October 2019
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WEPLH03	Redesign of ReA3 4-Rod RFQ	rfq, operation, simulation, linac	807
	A.S. Plastun, P.N. Ostroumov, A.C.C. Villari, Q. Zhao FRIB, East Lansing, Michigan, USA A.C.C. Villari, Q. Zhao NSCL, East Lansing, Michigan, USA
	Funding: Work supported by the U.S. DoE Office of Science under Cooperative Agreement DE-SC0000661 and the NSF under Cooperative Agreement PHY-1102511, the State of Michigan and Michigan State University. The present RFQ of ReA3 reaccelerator at Michigan State University (MSU) has been commissioned in 2010. This 4-rod RFQ was designed to accelerate the prebunched 80.5 MHz beams with the lowest Q/A = 1/5. However, the lack of proper cooling limited the RFQ performance to the pulsed operation with the lowest Q/A = 1/4. The design voltage for Q/A = 1/5 has never been reached even in a pulsed mode due to the sparking. In 2016 we initiated the upgrade of ReA3 RFQ to support high duty cycle (up to CW) operation with Q/A = 1/5 beams. The upgrade included the new rods with trapezoidal modulation, and new stems with improved cooling. The redesigned 80.5 MHz RFQ will consume only 65% rf power of the present RFQ for Q/A = 1/5 beam. It will provide the transmission up to 78% for 16.1 MHz beams and 89% for 80.5 MHz beams. High reliability and efficiency of the RFQ are very important for the going-on reaccelerator upgrade to ReA6 and for future operation as a part of FRIB. The electrodes have been manufactured and are being installed. The RF and beam tests are scheduled to summer 2019.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLH03
About •	paper received ※ 27 August 2019 paper accepted ※ 01 September 2019 issue date ※ 08 October 2019
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WEPLH04	Beam Envelope Reconstruction for FRIB-FS1 Transport Line Using Beam Position Monitors	quadrupole, linac, diagnostics, emittance	810
	T. Yoshimoto, S. Cogan, J.L. Crisp, K. Fukushima, S.M. Lidia, T. Maruta, P.N. Ostroumov, A.S. Plastun, T. Zhang, Q. Zhao FRIB, East Lansing, Michigan, USA
	Funding: This work is supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661, the State of Michigan and Michigan State University. The Facility for Rare Isotope Beam (FRIB) includes a heavy ion superconducting (SC) linac. Recently we completed beam commissioning of the Linac Segment 1 (LS1) and 45° bend section of the Folding Segment 1 (FS1). Four ion species, 40Ar⁹⁺, 20Ne⁶⁺, 86Kr¹⁷⁺ and 129Xe²⁶⁺ were successfully accelerated to a beam energy of 20.3 MeV/u. We explored the possibility of non-invasive beam diagnostics for online beam envelope monitoring based on beam quadrupole moments derived from Beam Position Monitors (BPMs). In future operations, various ion beam species will be accelerated and minimization of beam tuning time is critical. To address this requirement, it is beneficial to use BPMs to obtain beam Twiss parameters instead of wire scanners. This paper reports the results of BPM-based beam Twiss parameters evolution in the FS1. R. E. Shafer, "Laser Diagnostic for High Current H beams", Proc. 1998 Beam Instrumentation Workshop (Stanford). A.I.P. Conf. Proceedings, (451), 191.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLH04
About •	paper received ※ 27 August 2019 paper accepted ※ 16 November 2020 issue date ※ 08 October 2019
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WEPLH06	Commissioning Status of the FRIB Front End	rfq, linac, cavity, ECR	813
	H.T. Ren, J. Brandon, N.K. Bultman, K.D. Davidson, E. Daykin, T. Elkin, B. Galecka, P.E. Gibson, L. Hodges, K. Holland, D.D. Jager, M.G. Konrad, B.R. Kortum, S.M. Lidia, G. Machicoane, I.M. Malloch, H. Maniar, T. Maruta, G. Morgan, D.G. Morris, P. Morrison, A.C. Morton, P.N. Ostroumov, A.S. Plastun, E. Pozdeyev, X. Rao, T. Russo, J.W. Stetson, R. Walker, J. Wei, Y. Yamazaki, T. Yoshimoto, Q. Zhao, S. Zhao FRIB, East Lansing, Michigan, USA S. Renteria NSCL, East Lansing, Michigan, USA
	Funding: This work is supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661. The FRIB Front End was successfully commissioned in 2017 with commissioning goals achieved and Key Per-formance Parameters (KPP) demonstrated for both 40Ar⁹⁺ and 86Kr¹⁷⁺ beams. Two more ion species, 20Ne⁶⁺ and 129Xe²⁶⁺, have been commissioned on the Front End and delivered to the superconducting linac during the beam commissioning of Linac Segment 1 (LS1) in March 2019. In August 2019, Radio Frequency Quadrupole (RFQ) conditioning reached the full design power of 100 kW continuous wave (CW) that is required to accelerate Ura-nium beams. Start-up/shutdown procedures and opera-tional screens were developed for the Front End subsys-tems for trained operators, and auto-start and RF fast re-covery functions have been implemented for the Front End RFQ and bunchers. In this paper, we will present the current commissioning status of the Front End, and per-formance of the main technical systems, such as the ECR ion source and RFQ.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLH06
About •	paper received ※ 01 September 2019 paper accepted ※ 05 September 2019 issue date ※ 08 October 2019
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WEPLH07	Commissioning of the FRIB/NSCL New ReA3 4-Rod Radio Frequency Quadrupole Accelerator	rfq, vacuum, operation, cavity	817
	S. Nash, J.F. Brandon, D.B. Crisp, T. Summers, A.C.C. Villari, Q. Zhao NSCL, East Lansing, Michigan, USA P.N. Ostroumov, A.S. Plastun FRIB, East Lansing, Michigan, USA
	Funding: This work was supported by the National Science Foundation under Grant PHY-15-65546 The reaccelerator facility ReA3 at the National Superconducting Cyclotron Laboratory is a state-of-the-art accelerator for ions of rare and stable isotopes. The first stage of acceleration is provided by a 4-rod radio-frequency quadrupole (RFQ) at 80.5 MHz, which accelerates ions from 12 keV/u to 530 keV/u. The internal copper acceleration structure of the RFQ was re-designed. The goal was to improve transmission while allowing to operate the RFQ in CW and accelerating ions with A/Q from 2 to 5. In this paper, we summarize the steps involved in the disassembly of the existing structure, preparation work on the retrofitted vacuum vessel, installation of the new components, acceptance testing, and commissioning of the completed RFQ.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLH07
About •	paper received ※ 29 August 2019 paper accepted ※ 19 November 2019 issue date ※ 08 October 2019
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WEPLH09	FRIB Driver Linac Integration to be ready for Phased Beam Commissioning	SRF, cryomodule, cavity, linac	823
	H. Ao, S. Beher, N.K. Bultman, F. Casagrande, C. Compton, J.C. Curtin, K.D. Davidson, K. Elliott, V. Ganni, A. Ganshyn, P.E. Gibson, I. Grender, W. Hartung, L. Hodges, K. Holland, A. Hussain, M. Ikegami, S. Jones, P. Knudsen, S.M. Lidia, G. Machicoane, S.J. Miller, D.G. Morris, P.N. Ostroumov, J.T. Popielarski, L. Popielarski, J. Priller, T. Russo, K. Saito, S. Stanley, D.R. Victory, X. Wang, J. Wei, M. Xu, T. Xu, Y. Yamazaki, S. Zhao FRIB, East Lansing, Michigan, USA A. Facco INFN/LNL, Legnaro (PD), Italy R.E. Laxdal TRIUMF, Vancouver, Canada
	Funding: Work supported by the U.S. Department of Energy (DOE) Office of Science under Cooperative Agreement DE-SC0000661 The driver linac for Facility for Rare Isotope Beams (FRIB) will accelerate all stable ion beams from proton to uranium beyond 200 MeV/u with beam powers up to 400 kW. The linac now consists of 10⁴ superconducting quarter-wave resonators (QWR), which is the world largest number of low-beta SRF cavities operating at an accelerator facility. The first 3 QWR cryomodules (CM) (β = 0.041) were successfully integrated with cryogenics and other support systems for the 2nd Accelerator Readiness Review (ARR). The 3rd ARR scope that includes 11 QWR CM (β=0.085) and 1 QWR matching CM (β=0.085) was commissioned on schedule by January 2019, and then we met the Key Performance Parameters (KPP), accelerating Ar and Kr > 16 MeV/u at this stage, in a week upon the ARR authorization. We examine a variety of key factors to the successful commissioning, such as component testing prior to system integration, assessment steps of system/device readiness, and phased commissioning. This paper also reports on the integration process of the β=0.085 CMs including the test results, and the current progress on β=0.29 and 0.53 CMs in preparation for the upcoming 4th ARR.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLH09
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THYBA1	Status of the CBETA Cornell-BNL ERL Prototype	cavity, radiation, beam-loading, electron	923
	K.E. Deitrick, N. Banerjee, A.C. Bartnik, J.A. Crittenden, L. Cultrera, J. Dobbins, C.M. Gulliford, G.H. Hoffstaetter, W. Lou, P. Quigley, D. Sagan, K.W. Smolenski, D. Widger Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA J.S. Berg, S.J. Brooks, R.L. Hulsart, R.J. Michnoff, S. Peggs, D. Trbojevic BNL, Upton, New York, USA
	CBETA, the Cornell-BNL ERL Test Accelerator, is an SRF multi-turn ERL which has been commissioned in the one-turn configuration from March to July 2019. During this time, the project has demonstrated an energy acceptance of 1.5 in the FFA arc, high-transmission energy recovery performance, and increased the CBETA energy-recovered maximum average current.
	Slides THYBA1 [11.605 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THYBA1
About •	paper received ※ 28 August 2019 paper accepted ※ 06 September 2019 issue date ※ 08 October 2019
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THZBA3	Status of Beam Commissioning in FRIB Driver Linac	MEBT, emittance, cryomodule, quadrupole	951
	T. Maruta, S. Cogan, K. Fukushima, M. Ikegami, S.H. Kim, S.M. Lidia, G. Machicoane, F. Marti, D.G. Morris, P.N. Ostroumov, A.S. Plastun, J.T. Popielarski, J. Wei, T. Xu, T. Yoshimoto, T. Zhang, Q. Zhao, S. Zhao FRIB, East Lansing, Michigan, USA
	Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661, the State of Michigan and Michigan State University. The beam commissioning of linac segment 1 (LS1) composed of fifteen cryomodules consisting of total 10⁴ superconducting (SC) resonators and 36 SC solenoids was successfully completed. Four ion beam species, Ne, Ar, Kr and Xe were successfully accelerated up to 20.3 MeV/u. The FRIB driver linac in its current configuration became the highest energy continuous wave hadron linac. We will report a detailed study of beam dynamics in the LS1 prior to and after stripping with a carbon foil.
	Slides THZBA3 [11.377 MB]
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THZBA5	First Electron Cooling of Hadron Beams Using a Bunched Electron Beam	electron, cavity, laser, gun	957
	A.V. Fedotov, Z. Altinbas, M. Blaskiewicz, J.M. Brennan, D. Bruno, J.C. Brutus, M.R. Costanzo, K.A. Drees, W. Fischer, J.M. Fite, M. Gaowei, D.M. Gassner, X. Gu, J. Halinski, K. Hamdi, L.R. Hammons, T. Hayes, R.L. Hulsart, P. Inacker, J.P. Jamilkowski, Y.C. Jing, P.K. Kankiya, D. Kayran, J. Kewisch, D. Lehn, C.J. Liaw, C. Liu, J. Ma, G.J. Mahler, M. Mapes, A. Marusic, K. Mernick, C. Mi, R.J. Michnoff, T.A. Miller, M.G. Minty, S.K. Nayak, L.K. Nguyen, M.C. Paniccia, I. Pinayev, S. Polizzo, V. Ptitsyn, T. Rao, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, S. Seletskiy, F. Severino, T.C. Shrey, L. Smart, K.S. Smith, H. Song, A. Sukhanov, R. Than, P. Thieberger, S.M. Trabocchi, J.E. Tuozzolo, P. Wanderer, E. Wang, G. Wang, D. Weiss, B.P. Xiao, T. Xin, W. Xu, A. Zaltsman, H. Zhao, Z. Zhao BNL, Upton, New York, USA
	Funding: Work supported by the U.S. Department of Energy. The Low Energy RHIC electron Cooler (LEReC) was recently constructed and commissioned at BNL. The LEReC is the first electron cooler based on the RF acceleration of electron bunches (previous electron coolers all used DC beams). Bunched electron beams are necessary for cooling hadron beams at high energies. The challenges of such an approach include generation of electron beams suitable for cooling, delivery of electron beams of the required quality to the cooling sections without degradation of beam emittances and energy spread, achieving required small angles between electrons and ions in the cooling sections, precise energy matching between the two beams, high-current operation of the electron accelerator, as well as several physics effects related to bunched beam cooling. Following successful commissioning of the electron accelerator in 2018, the focus of the LEReC project in 2019 was on establishing electron-ion interactions and demonstration of cooling process using electron energy of 1.6MeV (ion energy of 3.85GeV/n), which is the lowest energy of interest. Here we report on the first demonstration of Au ion cooling in RHIC using this new approach.
	Slides THZBA5 [16.417 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THZBA5
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Paper

Title

Other Keywords

Page

MOYBA2

Commissioning of the Phase 2 and Phase 3 SuperKEKB / B-Factory

detector, luminosity, optics, injection

14

S. Nakamura
KEK, Ibaraki, Japan

The next generation of B-Factory, the SuperKEKB electron-positron collider at KEK (Japan) has started after two years shutdown from the Phase 1 commissioning in 2016. The first phase for the vacuum scrubbing in 2016 and the second phase focused on the verification of the novel "nano-beam" collision scheme were successfully completed in 2018. The modifications between Phase 1 and Phase 2 follows Phase 3 are installations of the final focus system and the Belle II detector. In order to accomplish the higher luminosity more than the predecessor KEKB , the nano-beam scheme is studied with higher bunch currents to reduce the beam-beam blowup which degrade the luminosity. The new collision scheme is reviewed and the luminosity performance and overall status in the Phase 2 and Phase 3 commissioning are presented.

Slides MOYBA2 [13.453 MB]

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MOYBA6

Accelerator Performance During the Beam Energy Scan II at RHIC in 2019

electron, operation, luminosity, cavity

26

C. Liu, I. Blacker, M. Blaskiewicz, K.A. Brown, D. Bruno, K.A. Drees, A.V. Fedotov, W. Fischer, C.J. Gardner, C.E. Giorgio, X. Gu, T. Hayes, H. Huang, R.L. Hulsart, D. Kayran, N.A. Kling, Y. Luo, D. Maffei, G.J. Marr, B. Martin, A. Marusic, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, C. Naylor, S. Nemesure, I. Pinayev, S. Polizzo, V.H. Ranjbar, D. Raparia, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, F. Severino, T.C. Shrey, K.S. Smith, S. Tepikian, P. Thieberger, A. Zaltsman, K. Zeno, I.Y. Zhang, W. Zhang
BNL, Upton, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
RHIC provided Au-Au collisions at beam energies of 9.8, 7.3, 4.59 and 3.85 GeV/nucleon during the first year of the Beam Energy Scan II in 2019. The physics goals at the first two higher beam energies were achieved. At the two lower beam energies, bunched electron beam cooling has been demonstrated successfully. The accelerator performance was improved compared to when RHIC was operated at these energies in earlier years. This article will introduce the challenges to operate RHIC at low energies and the corresponding countermeasures, and review the improvement of accelerator performance during the operation in 2019.

Slides MOYBA6 [6.579 MB]

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paper received ※ 21 August 2019 paper accepted ※ 06 September 2019 issue date ※ 08 October 2019

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MOZBA5

Optimized Linear and Second Order Chromaticity Setpoints for the Advanced Photon Source Upgrade

lattice, sextupole, simulation, photon

70

Y.P. Sun
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 nominal single particle dynamics optimizations of the Advanced Photon Source upgrade (APS-U) lattice are performed with dense numerical simulations of local momentum acceptance and dynamic acceptance. These simulations are quite time consuming, which may take weeks for optimizing one setpoint of linear chromaticity. In this paper, an alternative optimization method is adopted to generate optimized linear and second order chromaticity setpoints for the Advanced Photon Source upgrade lattice. This method is efficient in computing time needed, which is capable to generate a grid of optimized chromaticity setpoints in a relatively short time. The performance of these lattice solutions are verified by simulations with reasonable errors. These lattice solutions with different linear (or second order) chromaticity may be useful for the future APS-U commissioning and operations.

Slides MOZBA5 [3.350 MB]

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MOPLM24

LCLS-II Injector Commissioning Beam Based Measurements

electron, gun, laser, cathode

157

C.M. Zimmer, T.J. Maxwell, F. Zhou
SLAC, Menlo Park, California, USA

Funding: Department of Energy
Injector commissioning is underway for the LCLS-II MHz repetition rate FEL, currently under construction at SLAC. Methodology of injector beam-based measurements and early results with low beam charge will be presented, along with the software tools written to automate these various measurements.

Poster MOPLM24 [10.104 MB]

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MOPLO17

Large-Scale Dewar Testing of FRIB Production Cavities: Results

cavity, cryomodule, SRF, linac

270

W. Hartung, W. Chang, S.H. Kim, D. Norton, J.T. Popielarski, K. Saito, J.F. Schwartz, T. Xu, C. Zhang
FRIB, East Lansing, Michigan, USA

The Facility for Rare Isotope Beams (FRIB), under construction at Michigan State University (MSU), includes a superconducting driver linac to deliver ion beams at 200 MeV per nucleon. The driver linac requires 10⁴ quarter-wave resonators (QWRs, β = 0.041 and 0.085) and 220 half-wave resonators (HWRs, β = 0.29 and 0.54). The jacketed resonators are Dewar tested at MSU before installation into cryomodules. The cryomodules for β = 0.041, 0.085, and 0.29 have been completed and certified; 89% of the β = 0.54 HWRs have been certified (as of May 2019). The Dewar certification tests have provided valuable information on the performance of production QWRs and HWRs at 4.3 K and 2 K and on performance limits. Results will be presented.

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paper received ※ 08 November 2019 paper accepted ※ 26 November 2019 issue date ※ 08 October 2019

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TUPLH20

Commissioning of the CESR Upgrade for CHESS-U

HOM, wiggler, impedance, storage-ring

522

J.P. Shanks, G.W. Codner, M.J. Forster, D.L. Rubin, S. Wang, L. Ying
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: Funding for the CHESS-U upgrade provided by New York State Capital Grant #AA737 / CFA #53676
The Cornell Electron Storage Ring (CESR) was upgraded in the second half of 2018 to become a dedicated synchrotron light source, CHESS-U. The upgrade is by far the largest modification to CESR in its 40-year history, replacing one-sixth of the storage ring with six new double-bend achromats, increasing beam energy from 5.3 GeV to 6.0 GeV, and switching from two counter-rotating beams to a single on-axis positron beam. The new achromats include combined-function dipoles, a first in CESR, and reduce the horizontal emittance by a factor of four. Eight compact narrow-gap undulators (4.6mm vacuum chamber aperture) and one high-energy 24-pole wiggler feed a total of six new and five existing x-ray end stations from a single positron beam. Commissioning of CHESS-U took place in the first half of 2019. We report on the methods and results of beam commissioning, including initial beam accumulation, optics correction, characterization, and commissioning of compact permanent-magnet insertion devices.

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TUPLE08

Commissioning Update on RF Station #5 of AWA

high-voltage, klystron, electron, cavity

580

W. Liu, M.E. Conde, D.S. Doran, G. Ha, J.G. Power, J.H. Shao, C. Whiteford, E.E. Wisniewski
ANL, Lemont, Illinois, USA
C. Jing
Euclid Beamlabs LLC, Bolingbrook, USA

Funding: The US Department of Energy, Office of Science
The RF system of Argonne Wakefield Accelerator (AWA) facility has grown over the years from one RF power station into 4 RF power stations. The demand for RF power keeps growing as the capability of AWA continues to grow. Now the 5th RF station is needed to fulfill the RF power needs of AWA facility. Some details regarding the construction and commissioning of the 5th RF station of AWA facility are documented in this paper.

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLE08

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paper received ※ 29 August 2019 paper accepted ※ 05 September 2019 issue date ※ 08 October 2019

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WEYBB1

ELENA Commissioning

electron, proton, experiment, antiproton

626

D. Gamba, M.E. Angoletta, P. Belochitskii, L. Bojtár, F. Butin, C. Carli, B. Dupuy, Y. Dutheil, T. Eriksson, P. Freyermuth, C. Grech, M. Hori, J.R. Hunt, M. Jaussi, L.V. Jørgensen, B. Lefort, S. Pasinelli, L. Ponce, G. Tranquille
CERN, Meyrin, Switzerland
R. Gebel
FZJ, Jülich, Germany
C. Grech
University of Malta, Information and Communication Technology, Msida, Malta
M. Hori
MPQ, Garching, Munich, Germany

The Extra Low ENergy Antiproton storage ring (ELENA) is an upgrade project at the CERN AD (Antiproton Decelerator). ELENA will further decelerate the 5.3 MeV antiprotons coming from the AD down to 100 keV. ELENA features electron cooling for emittance control during deceleration thus preserving the beam intensity and allowing to extract bright bunches towards the experiments. The lower energy will allow for increasing the antiproton trapping efficiency up to two orders of magnitude, which is typically less than 1% with the present beam from AD. The ring was completed with the installation of the electron cooler at the beginning of 2018. Decelerated beams with characteristics close to the design values were obtained before the start of CERN Long Shutdown 2 (LS2). During LS2 electrostatic transfer lines from the ELENA ring to the experimental zones will be installed, replacing the magnetic transfer lines from the AD ring. The latest results of commissioning with H⁻ and antiprotons and the first observation of electron cooling in ELENA will be presented, together with an overview of the project and status and plans for LS2 and beyond.

Slides WEYBB1 [20.792 MB]

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WEYBB4

Progress of Liquid Lithium Stripper for FRIB

operation, vacuum, electron, gun

636

T. Kanemura, J. Gao, R. Madendorp, F. Marti, Y. Momozaki
FRIB, East Lansing, Michigan, USA
M.J. LaVere
MSU, East Lansing, Michigan, USA
Y. Momozaki
ANL, Lemont, Illinois, USA

Funding: This work is supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
The Facility for Rare Isotope Beams (FRIB) at Michigan State University is building a heavy ion linear accelerator (linac) to produce rare isotopes by the fragmentation method. At energies between 16 and 20 MeV/u ions are further stripped by a charge stripper increasing the energy gain downstream in the linac. The main challenges in the stripper design are high power deposited by the ions in the stripping media and radiation damage to the media itself. To overcome these challenges, self-recovering stripper media are the most suitable solutions. The FRIB baseline choice is a high-velocity thin film of liquid lithium*. Because liquid lithium is highly reactive with air, we have implemented rigorous safety measures. Since May 2018, the lithium stripper system has been operated safely at an offline test site to accumulate operational experience. Recently, we successfully completed a 10-day long unattended continuous operation without any issue, which proved the reliability of the system. The next step is to characterize the lithium film stability with diagnostics. In 2020, we plan to bring the lithium stripper into the accelerator tunnel and commission it with ion beams.
*Jie Wei, et al., TU1A04, Proceedings of LINAC 2012, Tel-Aviv, Israel

Slides WEYBB4 [6.012 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEYBB4

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WEZBA2

Experience and Lessons in FRIB Superconducting Quarter-Wave Resonator Commissioning

cavity, cryomodule, linac, controls

646

S.H. Kim, H. Ao, F. Casagrande, W. Chang, C. Compton, A. Facco, V. Ganni, E. Gutierrez, W. Hartung, N. Hasan, P. Knudsen, T.L. Larter, H. Maniar, S.J. Miller, D.G. Morris, P.N. Ostroumov, A.S. Plastun, J.T. Popielarski, L. Popielarski, H.T. Ren, K. Saito, M. Thrush, D.R. Victory, J. Wei, M. Xu, T. Xu, Y. Yamazaki, C. Zhang, S. Zhao
FRIB, East Lansing, Michigan, USA

The superconducting (SC) linear accelerator (linac) for the Facility for Rare Isotope Beams (FRIB) has one quarter-wave resonator (QWR) segment and two half-wave resonator (HWR) segments. The first linac segment (LS1) contains twelve β = 0.041 and ninety-two β = 0.085 QWRs operating at 80.5 MHz, and thirty-nine SC solenoids. Superconducting radiofrequency (SRF) commissioning and beam commissioning of LS1 was completed in April 2019. The design accelerating gradients (5.1 MV/m for β = 0.041 and 5.6 MV/m for β = 0.085) were achieved in all cavities with no multipacting or field emission issues. The cavity field met the design goals: peak-to-peak stability of ±1% in amplitude and ±1° in phase. We achieved 20.3 MeV/u ion beams of Ar, Kr, Ne, and Xe with LS1. In this paper, we will discuss lessons learned from the SRF commissioning of the cryomodules and methods developed for efficient testing, conditioning, and commissioning of more than 100 SC cavities, each with its own independent RF system.

Slides WEZBA2 [2.841 MB]

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WEPLM03

The LLRF Control Design and Validation at FRIB

LLRF, controls, cavity, cryomodule

667

S. Zhao, W. Chang, S.H. Kim, H. Maniar, D.G. Morris, P.N. Ostroumov, J.T. Popielarski, H.T. Ren, N.R. Usher
FRIB, East Lansing, Michigan, USA
N.R. Usher
Ionetix, Lansing, Michigan, USA

Funding: This work is supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
One of the challenges in designing the low level radio frequency (LLRF) controllers for the Facility for Rare Isotope Beams (FRIB) is the various types of cavities, which include 5 different frequencies ranging from 40.25 MHz up to 322 MHz, and 4 different types of tuners. In this paper, the design strategy taken to achieve flexibility and low cost and the choices made to accommodate the varieties will be discussed. The approach also allowed easy adaptation to major design changes such as replac-ing two cryo-modules with two newly designed room temperature bunchers and the addition of high-voltage bias to suppress multi-pacting in half wave resonators (HWRs). With the successful completion of the third accelerator readiness review (ARR03) commissioning in early 2019, most of the design has been validated in the real accelerator system, leaving only HWRs which are constantly undergoing tests in cryo-module bunker. The integrated spark detector design for HWRs will also be tested in the near future.

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WEPLM63

Development of a Secondary Sn Source for Nb₃Sn Coating of Half-Wave Coaxial Resonator

cavity, niobium, SRF, superconductivity

735

J.K. Tiskumara, J.R. Delayen, H. Park
ODU, Norfolk, Virginia, USA
G.V. Eremeev
JLab, Newport News, Virginia, USA
U. Pudasaini
The College of William and Mary, Williamsburg, Virginia, USA

Superconducting thin films have the potential of reducing the cost of particle accelerators. Among the potential materials, Nb₃Sn has a higher critical temperature and higher critical field compared to niobium. Sn vapor diffusion method is the preferred technique to coat niobium cavities. Although there are several thin-film-coated basic cavity models that are tested at their specific frequencies, the Half-wave resonator could provide us data across frequencies of interest for particle accelerators. With its advanced geometry, increased area, increased number of ports and hard to reach areas, the half-wave resonator needs a different coating approach, in particular, a development of a secondary Sn source. We are commissioning a secondary Sn source in the coating system and expand the current coating system at JLab to coat complex cavity models.

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paper received ※ 27 August 2019 paper accepted ※ 06 September 2019 issue date ※ 08 October 2019

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WEPLM70

FRIB Tuner Performance and Improvement

cavity, linac, cryomodule, controls

755

J.T. Popielarski, W. Chang, C. Compton, W. Hartung, S.H. Kim, E.S. Metzgar, S.J. Miller, K. Saito, J.F. Schwartz, T. Xu
FRIB, East Lansing, Michigan, USA

Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
The Facility for Rare Isotope Beams (FRIB) is under construction at Michigan State University (MSU). The FRIB superconducting driver linac will accelerate ion beams to 200 MeV per nucleon. The driver linac requires 10⁴ quarter-wave resonators (QWRs, β = 0.041 and 0.085) and 220 half-wave resonators (HWRs, β = 0.29 and 0.54). The cryomodules for β = 0.041, 0.085, and 0.29 have been completed and certified; 32 out of 49 cryomodules are certified via bunker test (as of March 2019). FRIB QWR cavities have a demountable niobium tuning plate which uses a warm external stepper motor and the FRIB HWR cavities use pneumatic actuated bellows. Progress on the preparation and performance of the tuners is presented in this paper along with improvements made to ensure meeting frequency specification.

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paper received ※ 26 September 2019 paper accepted ※ 19 November 2019 issue date ※ 08 October 2019

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WEPLS04

Simulations of Low Energy Au⁷⁸⁺ Losses in RHIC

electron, lattice, optics, closed-orbit

775

G. Robert-Demolaize, K.A. Drees, Y. Luo
BNL, Upton, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The RHIC Run19 BES-II program features the commissioning of the Low Energy RHIC electron Cooling (LEReC) Project, which uses electron cooling techniques to compensate for intra-beam scattering and thus to improve the luminosity lifetime. During RHIC operations at 3.85 GeV (beam energy) with LEReC, one needs to ensure that the electron beam energy is properly matched for cooling purposes: if so, some of the circulating Au-79 ions can recombine with an electron, turning into Au-78 and circulating with a large momentum offset. Part of the LEReC commissioning steps is therefore to drive a maximized number of Au-78 ions towards a chosen location of the RHIC mechanical aperture to generate particle showers that can be detected by a Recombination Monitor outside the cryostat. This article introduces the baseline lattice design, then discusses the few scenarios considered for optimizing Au-78 losses at a given location. Each scenario is then simulated using new tracking tools for generating beam loss maps.

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLS04

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paper received ※ 27 August 2019 paper accepted ※ 03 September 2019 issue date ※ 08 October 2019

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WEPLH03

Redesign of ReA3 4-Rod RFQ

rfq, operation, simulation, linac

807

A.S. Plastun, P.N. Ostroumov, A.C.C. Villari, Q. Zhao
FRIB, East Lansing, Michigan, USA
A.C.C. Villari, Q. Zhao
NSCL, East Lansing, Michigan, USA

Funding: Work supported by the U.S. DoE Office of Science under Cooperative Agreement DE-SC0000661 and the NSF under Cooperative Agreement PHY-1102511, the State of Michigan and Michigan State University.
The present RFQ of ReA3 reaccelerator at Michigan State University (MSU) has been commissioned in 2010. This 4-rod RFQ was designed to accelerate the prebunched 80.5 MHz beams with the lowest Q/A = 1/5. However, the lack of proper cooling limited the RFQ performance to the pulsed operation with the lowest Q/A = 1/4. The design voltage for Q/A = 1/5 has never been reached even in a pulsed mode due to the sparking. In 2016 we initiated the upgrade of ReA3 RFQ to support high duty cycle (up to CW) operation with Q/A = 1/5 beams. The upgrade included the new rods with trapezoidal modulation, and new stems with improved cooling. The redesigned 80.5 MHz RFQ will consume only 65% rf power of the present RFQ for Q/A = 1/5 beam. It will provide the transmission up to 78% for 16.1 MHz beams and 89% for 80.5 MHz beams. High reliability and efficiency of the RFQ are very important for the going-on reaccelerator upgrade to ReA6 and for future operation as a part of FRIB. The electrodes have been manufactured and are being installed. The RF and beam tests are scheduled to summer 2019.

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLH03

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paper received ※ 27 August 2019 paper accepted ※ 01 September 2019 issue date ※ 08 October 2019

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WEPLH04

Beam Envelope Reconstruction for FRIB-FS1 Transport Line Using Beam Position Monitors

quadrupole, linac, diagnostics, emittance

810

T. Yoshimoto, S. Cogan, J.L. Crisp, K. Fukushima, S.M. Lidia, T. Maruta, P.N. Ostroumov, A.S. Plastun, T. Zhang, Q. Zhao
FRIB, East Lansing, Michigan, USA

Funding: This work is supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661, the State of Michigan and Michigan State University.
The Facility for Rare Isotope Beam (FRIB) includes a heavy ion superconducting (SC) linac. Recently we completed beam commissioning of the Linac Segment 1 (LS1) and 45° bend section of the Folding Segment 1 (FS1). Four ion species, 40Ar⁹⁺, 20Ne⁶⁺, 86Kr¹⁷⁺ and 129Xe²⁶⁺ were successfully accelerated to a beam energy of 20.3 MeV/u. We explored the possibility of non-invasive beam diagnostics for online beam envelope monitoring based on beam quadrupole moments derived from Beam Position Monitors (BPMs)*. In future operations, various ion beam species will be accelerated and minimization of beam tuning time is critical. To address this requirement, it is beneficial to use BPMs to obtain beam Twiss parameters instead of wire scanners. This paper reports the results of BPM-based beam Twiss parameters evolution in the FS1.
* R. E. Shafer, "Laser Diagnostic for High Current H beams", Proc. 1998 Beam Instrumentation Workshop (Stanford). A.I.P. Conf. Proceedings, (451), 191.

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLH04

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paper received ※ 27 August 2019 paper accepted ※ 16 November 2020 issue date ※ 08 October 2019

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WEPLH06

Commissioning Status of the FRIB Front End

rfq, linac, cavity, ECR

813

H.T. Ren, J. Brandon, N.K. Bultman, K.D. Davidson, E. Daykin, T. Elkin, B. Galecka, P.E. Gibson, L. Hodges, K. Holland, D.D. Jager, M.G. Konrad, B.R. Kortum, S.M. Lidia, G. Machicoane, I.M. Malloch, H. Maniar, T. Maruta, G. Morgan, D.G. Morris, P. Morrison, A.C. Morton, P.N. Ostroumov, A.S. Plastun, E. Pozdeyev, X. Rao, T. Russo, J.W. Stetson, R. Walker, J. Wei, Y. Yamazaki, T. Yoshimoto, Q. Zhao, S. Zhao
FRIB, East Lansing, Michigan, USA
S. Renteria
NSCL, East Lansing, Michigan, USA

Funding: This work is supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
The FRIB Front End was successfully commissioned in 2017 with commissioning goals achieved and Key Per-formance Parameters (KPP) demonstrated for both 40Ar⁹⁺ and 86Kr¹⁷⁺ beams. Two more ion species, 20Ne⁶⁺ and 129Xe²⁶⁺, have been commissioned on the Front End and delivered to the superconducting linac during the beam commissioning of Linac Segment 1 (LS1) in March 2019. In August 2019, Radio Frequency Quadrupole (RFQ) conditioning reached the full design power of 100 kW continuous wave (CW) that is required to accelerate Ura-nium beams. Start-up/shutdown procedures and opera-tional screens were developed for the Front End subsys-tems for trained operators, and auto-start and RF fast re-covery functions have been implemented for the Front End RFQ and bunchers. In this paper, we will present the current commissioning status of the Front End, and per-formance of the main technical systems, such as the ECR ion source and RFQ.

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLH06

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paper received ※ 01 September 2019 paper accepted ※ 05 September 2019 issue date ※ 08 October 2019

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WEPLH07

Commissioning of the FRIB/NSCL New ReA3 4-Rod Radio Frequency Quadrupole Accelerator

rfq, vacuum, operation, cavity

817

S. Nash, J.F. Brandon, D.B. Crisp, T. Summers, A.C.C. Villari, Q. Zhao
NSCL, East Lansing, Michigan, USA
P.N. Ostroumov, A.S. Plastun
FRIB, East Lansing, Michigan, USA

Funding: This work was supported by the National Science Foundation under Grant PHY-15-65546
The reaccelerator facility ReA3 at the National Superconducting Cyclotron Laboratory is a state-of-the-art accelerator for ions of rare and stable isotopes. The first stage of acceleration is provided by a 4-rod radio-frequency quadrupole (RFQ) at 80.5 MHz, which accelerates ions from 12 keV/u to 530 keV/u. The internal copper acceleration structure of the RFQ was re-designed. The goal was to improve transmission while allowing to operate the RFQ in CW and accelerating ions with A/Q from 2 to 5. In this paper, we summarize the steps involved in the disassembly of the existing structure, preparation work on the retrofitted vacuum vessel, installation of the new components, acceptance testing, and commissioning of the completed RFQ.

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLH07

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paper received ※ 29 August 2019 paper accepted ※ 19 November 2019 issue date ※ 08 October 2019

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WEPLH09

FRIB Driver Linac Integration to be ready for Phased Beam Commissioning

SRF, cryomodule, cavity, linac

823

H. Ao, S. Beher, N.K. Bultman, F. Casagrande, C. Compton, J.C. Curtin, K.D. Davidson, K. Elliott, V. Ganni, A. Ganshyn, P.E. Gibson, I. Grender, W. Hartung, L. Hodges, K. Holland, A. Hussain, M. Ikegami, S. Jones, P. Knudsen, S.M. Lidia, G. Machicoane, S.J. Miller, D.G. Morris, P.N. Ostroumov, J.T. Popielarski, L. Popielarski, J. Priller, T. Russo, K. Saito, S. Stanley, D.R. Victory, X. Wang, J. Wei, M. Xu, T. Xu, Y. Yamazaki, S. Zhao
FRIB, East Lansing, Michigan, USA
A. Facco
INFN/LNL, Legnaro (PD), Italy
R.E. Laxdal
TRIUMF, Vancouver, Canada

Funding: Work supported by the U.S. Department of Energy (DOE) Office of Science under Cooperative Agreement DE-SC0000661
The driver linac for Facility for Rare Isotope Beams (FRIB) will accelerate all stable ion beams from proton to uranium beyond 200 MeV/u with beam powers up to 400 kW. The linac now consists of 10⁴ superconducting quarter-wave resonators (QWR), which is the world largest number of low-beta SRF cavities operating at an accelerator facility. The first 3 QWR cryomodules (CM) (β = 0.041) were successfully integrated with cryogenics and other support systems for the 2nd Accelerator Readiness Review (ARR). The 3rd ARR scope that includes 11 QWR CM (β=0.085) and 1 QWR matching CM (β=0.085) was commissioned on schedule by January 2019, and then we met the Key Performance Parameters (KPP), accelerating Ar and Kr > 16 MeV/u at this stage, in a week upon the ARR authorization. We examine a variety of key factors to the successful commissioning, such as component testing prior to system integration, assessment steps of system/device readiness, and phased commissioning. This paper also reports on the integration process of the β=0.085 CMs including the test results, and the current progress on β=0.29 and 0.53 CMs in preparation for the upcoming 4th ARR.

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLH09

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paper received ※ 02 September 2019 paper accepted ※ 03 September 2019 issue date ※ 08 October 2019

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THYBA1

Status of the CBETA Cornell-BNL ERL Prototype

cavity, radiation, beam-loading, electron

923

K.E. Deitrick, N. Banerjee, A.C. Bartnik, J.A. Crittenden, L. Cultrera, J. Dobbins, C.M. Gulliford, G.H. Hoffstaetter, W. Lou, P. Quigley, D. Sagan, K.W. Smolenski, D. Widger
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
J.S. Berg, S.J. Brooks, R.L. Hulsart, R.J. Michnoff, S. Peggs, D. Trbojevic
BNL, Upton, New York, USA

CBETA, the Cornell-BNL ERL Test Accelerator, is an SRF multi-turn ERL which has been commissioned in the one-turn configuration from March to July 2019. During this time, the project has demonstrated an energy acceptance of 1.5 in the FFA arc, high-transmission energy recovery performance, and increased the CBETA energy-recovered maximum average current.

Slides THYBA1 [11.605 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THYBA1

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paper received ※ 28 August 2019 paper accepted ※ 06 September 2019 issue date ※ 08 October 2019

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THZBA3

Status of Beam Commissioning in FRIB Driver Linac

MEBT, emittance, cryomodule, quadrupole

951

T. Maruta, S. Cogan, K. Fukushima, M. Ikegami, S.H. Kim, S.M. Lidia, G. Machicoane, F. Marti, D.G. Morris, P.N. Ostroumov, A.S. Plastun, J.T. Popielarski, J. Wei, T. Xu, T. Yoshimoto, T. Zhang, Q. Zhao, S. Zhao
FRIB, East Lansing, Michigan, USA

Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661, the State of Michigan and Michigan State University.
The beam commissioning of linac segment 1 (LS1) composed of fifteen cryomodules consisting of total 10⁴ superconducting (SC) resonators and 36 SC solenoids was successfully completed. Four ion beam species, Ne, Ar, Kr and Xe were successfully accelerated up to 20.3 MeV/u. The FRIB driver linac in its current configuration became the highest energy continuous wave hadron linac. We will report a detailed study of beam dynamics in the LS1 prior to and after stripping with a carbon foil.

Slides THZBA3 [11.377 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THZBA3

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paper received ※ 04 September 2019 paper accepted ※ 20 November 2019 issue date ※ 08 October 2019

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THZBA5

First Electron Cooling of Hadron Beams Using a Bunched Electron Beam

electron, cavity, laser, gun

957

A.V. Fedotov, Z. Altinbas, M. Blaskiewicz, J.M. Brennan, D. Bruno, J.C. Brutus, M.R. Costanzo, K.A. Drees, W. Fischer, J.M. Fite, M. Gaowei, D.M. Gassner, X. Gu, J. Halinski, K. Hamdi, L.R. Hammons, T. Hayes, R.L. Hulsart, P. Inacker, J.P. Jamilkowski, Y.C. Jing, P.K. Kankiya, D. Kayran, J. Kewisch, D. Lehn, C.J. Liaw, C. Liu, J. Ma, G.J. Mahler, M. Mapes, A. Marusic, K. Mernick, C. Mi, R.J. Michnoff, T.A. Miller, M.G. Minty, S.K. Nayak, L.K. Nguyen, M.C. Paniccia, I. Pinayev, S. Polizzo, V. Ptitsyn, T. Rao, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, S. Seletskiy, F. Severino, T.C. Shrey, L. Smart, K.S. Smith, H. Song, A. Sukhanov, R. Than, P. Thieberger, S.M. Trabocchi, J.E. Tuozzolo, P. Wanderer, E. Wang, G. Wang, D. Weiss, B.P. Xiao, T. Xin, W. Xu, A. Zaltsman, H. Zhao, Z. Zhao
BNL, Upton, New York, USA

Funding: Work supported by the U.S. Department of Energy.
The Low Energy RHIC electron Cooler (LEReC) was recently constructed and commissioned at BNL. The LEReC is the first electron cooler based on the RF acceleration of electron bunches (previous electron coolers all used DC beams). Bunched electron beams are necessary for cooling hadron beams at high energies. The challenges of such an approach include generation of electron beams suitable for cooling, delivery of electron beams of the required quality to the cooling sections without degradation of beam emittances and energy spread, achieving required small angles between electrons and ions in the cooling sections, precise energy matching between the two beams, high-current operation of the electron accelerator, as well as several physics effects related to bunched beam cooling. Following successful commissioning of the electron accelerator in 2018, the focus of the LEReC project in 2019 was on establishing electron-ion interactions and demonstration of cooling process using electron energy of 1.6MeV (ion energy of 3.85GeV/n), which is the lowest energy of interest. Here we report on the first demonstration of Au ion cooling in RHIC using this new approach.

Slides THZBA5 [16.417 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THZBA5

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paper received ※ 16 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019

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