Paper | Title | Page |
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MOPS086 | Beam Breakup Simulation for the PEP-X ERL | 805 |
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Funding: The work is supported by the U.S. Department of Energy under contract No. DE-AC02-76SF00515. The transverse beam breakup (BBU) is one of the dominant factors in ERL for the available beam current. A tracking code built in Matlab is developed and benchmarked by comparing with the analytical solutions with the simple model. Study on the threshold current and emittance growth due to the transverse BBU for PEP-X ERL are presented in this paper. |
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WEPC045 | Transverse Emittance Reduction with Tapered Foil | 2112 |
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Funding: The work is supported by the U.S. Department of Energy under contract No. DE-AC02-76SF00515. The idea of reducing transverse emittance with tapered energy-loss foil is proposed by J.M. Peterson in 1980s and recently by B. Carlsten. In present paper, we present the physical model of tapered energy-loss foil and analyze the emittance reduction using the concept of eigen emittance. The study shows that, to reduce transverse emittance, one should collimate at least 4% of particles which has either much low energy or large transverse divergence. The multiple coulomb scattering is not trivial, leading to a limited emittance reduction ratio. |
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