Longitudinal collective echoes in coasting particle beams
Longitudinal ballistic and collective beam echoes with diffusion effects are investigated theoretically. In the presence of the space-charge impedance, the collective echo amplitude is obtained as a closed form expression. In contrast to the ballistic case, the collective echo amplitude consists of...
Main Authors: | , , , |
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Format: | Article |
Language: | English |
Published: |
American Physical Society
2003-01-01
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Series: | Physical Review Special Topics. Accelerators and Beams |
Online Access: | http://doi.org/10.1103/PhysRevSTAB.6.014205 |
Summary: | Longitudinal ballistic and collective beam echoes with diffusion effects are investigated theoretically. In the presence of the space-charge impedance, the collective echo amplitude is obtained as a closed form expression. In contrast to the ballistic case, the collective echo amplitude consists of one maximum at time t_{echo}. The echo amplitude grows up and damps down with a rate proportional to the Landau damping rate of space-charge waves. The effect of weak diffusion is found to modify the ballistic and the collective echo amplitudes in the same manner. This effect of diffusion was confirmed using a “noiseless,” grid-based simulation code. As a first application the amount of numerical diffusion in our simulation code was determined using the echo effect. |
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ISSN: | 1098-4402 |