Author: Wienands, U.
Paper Title Page
TUPA23 First Beam Results Using the 10-kW Harmonic Rf Solid-State Amplifier for the APS Particle Accumulator Ring 398
 
  • K.C. Harkay, T.G. Berenc, J.R. Calvey, J.C. Dooling, H. Shang, T.L. Smith, Y. Sun, U. Wienands
    ANL, Lemont, Illinois, USA
 
  Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
The Advanced Photon Source (APS) particle accumulator ring (PAR) was designed to accumulate linac pulses into a single bunch using a fundamental radio frequency (rf) system, and longitudinally compress the beam using a harmonic rf system prior to injection into the booster. The APS Upgrade injectors will need to supply full-current bunch replacement with high single-bunch charge for swap-out injection in the new storage ring. Significant bunch lengthening is observed in the PAR at high charge, which negatively affects beam capture in the booster. Predictions showed that the bunch length could be compressed to better match the booster acceptance using a combination of higher beam energy and higher harmonic gap voltage. A new 10-kW harmonic rf solid-state amplifier (SSA) was installed in 2021 to raise the gap voltage and improve bunch compression. The SSA has been operating reliably. Initial results show that the charge-dependent bunch lengthening in PAR with higher gap voltage agrees qualitatively with predictions. A tool was written to automate bunch length data acquisition. Future plans to increase the beam energy, which makes the SSA more effective, will also be summarized.
 
poster icon Poster TUPA23 [2.477 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA23  
About • Received ※ 03 August 2022 — Revised ※ 05 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 07 October 2022
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THYD4 Progress on the APS-U Injector Upgrade 859
 
  • J.R. Calvey, T. Fors, K.C. Harkay, U. Wienands
    ANL, Lemont, Illinois, USA
 
  Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
For the APS-Upgrade, it was decided to leave the present APS injector chain in place and make individual improvements where needed. The main challenges faced by the injectors are delivering a high charge bunch (up to 16 nC in a single shot) to the storage ring, operating the booster synchrotron and storage ring at different rf frequencies, and maintaining good charge stability during APS-U operations. This paper will summarize recent progress on the injector upgrade. Topics include bucket targeting with the new injection/extraction timing system (IETS), modeling of high charge longitudinal instability in the PAR, and measurements of charge stability for different modes of operation.
 
slides icon Slides THYD4 [2.015 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-THYD4  
About • Received ※ 19 July 2022 — Accepted ※ 11 August 2022 — Issue date ※ 22 August 2022  
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