Study of Fast Instability in Fermilab Recycler

Conference · Wed Jun 01 04:00:00 EDT 2016

DOI:https://doi.org/10.18429/JACoW-IPAC2016-TUPOR029· OSTI ID:1280863

Antipov, Sergey ^[1]; Adamson, Philip ^[2]; Nagaitsev, Sergei ^[2]; Yang, Ming-Jen ^[2]

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1. Chicago U.
2. Fermilab

One of the factors which may limit the intensity in the Fermilab Recycler is a fast transverse instability. It develops within a hundred turns and, in certain conditions, may lead to a beam loss. Various peculiar features of the instability: its occurrence only above a certain intensity threshold, and only in horizontal plane, as well as the rate of the instability, suggest that its cause is electron cloud. We studied the phenomena by observing the dynamics of stable and unstable beam. We found that beam motion can be stabilized by a clearing bunch, which confirms the electron cloud nature of the instability. The findings suggest electron cloud trapping in Recycler combined function mag-nets. Bunch-by-bunch measurements of betatron tune show a tune shift towards the end of the bunch train and allow the estimation of the density of electron cloud and the rate of its build-up. The experimental results are in agreement with numerical simulations of electron cloud build-up and its interaction with the beam.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 1280863
• Report Number(s): FERMILAB-CONF-16-144-AD; 1470005
• Country of Publication: United States
• Language: English

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