Author: Bhat, C.M.
Paper Title Page
MOP02 Recent Improvements in the Beam Capture at Fermilab Booster for High Intensity Operation 23
 
  • C.M. Bhat, S. Chaurize, P. Derwent, M.W. Domeier, V.M. Grzelak, W. Pellico, J. Reid, B.A. Schupbach, C.-Y. Tan, A.K. Triplett
    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 the oldest RCS in operation in the world. In current operations, it accelerates ~4.5E12ppp to 8 GeV at 15 Hz and will be upgraded to >6.7E12ppp at 20 Hz in the PIP-II era. Booster has 22 RF cavities with each capable of providing ~50 kV. These cavities are divided into two groups: A & B. In the tunnel, the cavities are cavities are placed in a BA, AB, ’ sequence. At injection, A & B cavities have anti-parallel RF phase which results in a net zero RF voltage on the beam. During beam capture, the RF voltage is increased adiabatically by decreasing the relative phase between them. At the end of beam capture, the feedback is turned on for beam acceleration. It is vital that for current operations and in the PIP-II era that these cavities are properly matched in both magnitude and phase to preserve the longitudinal emittance during the early part of the beam cycle and to offer full RF voltage on the beam. In this paper we describe the how the cavities are distributed and how the phases are measured with beam and then corrected and balanced. Data with high intensity beam capture is also presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-HB2021-MOP02  
About • Received ※ 17 October 2021 — Revised ※ 16 November 2021 — Accepted ※ 22 November 2021 — Issue date ※ 28 January 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
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  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)