Author: Popielarski, L.
Paper Title Page
WEZBA2 Experience and Lessons in FRIB Superconducting Quarter-Wave Resonator Commissioning 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 icon Slides WEZBA2 [2.841 MB]  
DOI • reference for this paper ※  
About • paper received ※ 03 September 2019       paper accepted ※ 05 December 2019       issue date ※ 08 October 2019  
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WEPLM47 Analysis of High Field Q-Slope (HFQS) Causes and Development of New Chemical Polishing Acid 699
SUPLS04   use link to see paper's listing under its alternate paper code  
  • D. Luo, E.S. Metzgar, L. Popielarski, K. Saito, S.M. Shanab, G.V. Simpson
    FRIB, East Lansing, Michigan, USA
  • T. Nakajima, I. Nasu, J. Taguchi
    Nomura Plating Co, Ltd., Osaka, Japan
  Funding: U.S. National Science Foundation under Grant PHY-1565546.
In our previous studies of High Field Q-slope (HFQS) we have concluded that nitrogen contamination from the nitric acid is the main cause of the degradation of the Q in buffered chemical polished cavities. Our conclusion is made based on previously unresolved phenomena which are found from huge amount of published cavity test data, include fine grain, large grain and single crystal cavities treated with EP and BCP. According to this analysis, we have started developing new nitrogen-free chemical polishing acid. Hydrogen peroxide with HF mixture was reported able to react with Nb, and there’s no extra element contamination in it, so we replace the conventional BCP with this mixture to start our study. In this paper, some Nb coupon sample results with new acid will be reported. We complete the first step of developing the new acid and we got the Nb finish roughness no worse than conventional BCP.
DOI • reference for this paper ※  
About • paper received ※ 13 September 2019       paper accepted ※ 04 December 2019       issue date ※ 08 October 2019  
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WEPLH09 FRIB Driver Linac Integration to be ready for Phased Beam Commissioning 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 ※  
About • paper received ※ 02 September 2019       paper accepted ※ 03 September 2019       issue date ※ 08 October 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)