| Autor: |
Timothy W. Koeth, B. Beaudoin, S. Bernal, I. Haber, R. A. Kishek, M. Reiser, P. G. O’Shea, Steven H. Gold, Gregory S. Nusinovich |
| Rok vydání: |
2010 |
| Předmět: |
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| Zdroj: |
ResearcherID |
| ISSN: |
0094-243X |
| DOI: |
10.1063/1.3520396 |
| Popis: |
The University of Maryland Electron Ring (UMER) is a facility to study the long‐path length physics of a highly space‐charge dominated beam. Optimizing the ring characteristics to maximize beam lifetime has required an understanding of both the longitudinal and transverse dynamics of the beam and how they are coupled. A combination of experimental and numerical evidence is presented to show that front end of the injected bunch is accelerated by longitudinal space charge forces while the back of the same bunch is similarly decelerated leading to a longitudinal expansion of the injected bunch. This continues until the head overtakes the tail of the preceding turn. A significant portion of the apparent beam current decay is actually due to the merging of the head and tail, which results in a difficult‐to‐measure DC component of the beam. We also present a novel measurement technique to examine this longitudinal behavior that uses a voltage pulse applied between the horizontal plates at a beam position monitor. The pulse amplitude is sufficient to deflect the beam so that it intercepts the chamber wall. The resulting notch in the beam current, which can be varied in time, allows reconstruction of the DC component. Combined with simulations of the longitudinal and transverse beam characteristics this procedure provides data that can be used to understand the underlying beam dynamics. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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