Paper |
Title |
Page |
MOPP105 |
Compact, Tunable RF Cavities
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802 |
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- M. Popovic, C. M. Ankenbrandt, E. Griffin, A. Moretti, R. E. Tomlin
Fermilab, Batavia, Illinois
- M. Alsharo'a, I. B. Enchevich, R. P. Johnson, S. Korenev
Muons, Inc, Batavia
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New developments in the design of fixed-field alternating gradient (FFAG) synchrotrons have sparked interest in their use as rapid-cycling, high intensity accelerators of ions, protons, muons, and electrons. Potential applications include proton drivers for neutron or muon production, rapid muon accelerators, electron accelerators for synchrotron light sources, and medical accelerators of protons and light ions for cancer therapy. Compact RF cavities that tune rapidly over various frequency ranges are needed to provide the acceleration in FFAG lattices. An innovative design of a compact RF cavity that uses orthogonally biased ferrite for fast frequency tuning and liquid dielectric to adjust the frequency range is being developed using physical prototypes and computer models.
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MOPP080 |
Studies of Breakdown in a Pressurized RF Cavity
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736 |
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- M. BastaniNejad, A. A. Elmustafa
Old Dominion University, Norfolk, Virginia
- M. Alsharo'a, P. M. Hanlet, R. P. Johnson, S. Korenev, M. Kuchnir, D. J. Newsham, R. Sah
Muons, Inc, Batavia
- C. M. Ankenbrandt, A. Moretti, M. Popovic, K. Yonehara
Fermilab, Batavia, Illinois
- D. M. Kaplan
Illinois Institute of Technology, Chicago, Illinois
- D. Li
LBNL, Berkeley, California
- D. Rose, C. H. Thoma, D. R. Welch
Voss Scientific, Albuquerque, New Mexico
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Previous studies of RF breakdown in a cavity pressurized with dense hydrogen gas have indicated that breakdown probability is proportional to a high power of the surface electromagnetic field. This behavior is similar to the Fowler-Nordheim description of electron emission from a cold cathode, and it implies that breakdown is a quantum mechanical effect that is characterized by the work function of the cavity metal. We describe our present efforts to measure the distributions of work functions at the nanoscale level on the surfaces of the electrodes used in breakdown studies, and to understand how the RF conditioning process affects them.
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