Author: Eddy, N.
Paper Title Page
MOP22 A Dedicated Wake-Building Feedback System to Study Single Bunch Instabilities in the Presence of Strong Space Charge 135
 
  • R. Ainsworth, A.V. Burov, N. Eddy, A. Semenov
    Fermilab, Batavia, Illinois, USA
 
  Recent advances in the theoretical understanding of beam stability in the presence of strong space charge, has suggested a new class of instabilities known as convective instabilities. A novel approach to excite and study these instabilities will be to install a ‘waker’ system, a dedicated wake-building feedback system. The System was installed in the Fermilab Recycler and commissioned during 2021. The first results are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-HB2021-MOP22  
About • Received ※ 19 October 2021 — Revised ※ 20 October 2021 — Accepted ※ 26 November 2021 — Issue date ※ 12 April 2022
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MOP23 Coupled Bunch Instabilities Growth in the Fermilab Booster During Acceleration Cycle 140
 
  • C.M. Bhat, N. Eddy
    Fermilab, Batavia, Illinois, USA
 
  Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics.
The Fermilab Booster is an RCS with h=84 and gammaT =5.47 and, during standard operation it accelerates ~4.5E12ppBc from 400 MeV to 8 GeV at 15 Hz. The Booster is being upgraded to handle higher beam intensity >6.7E12ppBc and repetition rate of 20Hz. In the current mode of operation, we perform multi-turn beam injection and capture beam in h=84 system adiabatically. However, we have observed coupled bunch (CB) instabilities in the extracted beam. This issue is expected to worsen at higher beam intensities. In principle, for h=84 one expects 41 modes of oscillations contributing to these CB instabilities. Currently, we have a digital mode damper to mitigate prominent CB modes [1]. We would like to understand at what time in the beam cycle a particular mode is going to originate and how much it contributes at a different time of the cycle. In this regard, we have collected wall current monitor data from injection to extraction and looked for the start of a particular mode of CB instability and its growth for different intensities. This paper presents the results from this study and future plans to mitigate the CB instability in Booster.
[1] Nathan Eddy (private communications, 2020).
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-HB2021-MOP23  
About • Received ※ 17 October 2021 — Accepted ※ 22 November 2021 — Issue; date; ※; 22 January 2022  
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