Measurement of coherent beam-beam tune shift under crabbing collision at KEKB
Effective head-on collision and improvement in specific luminosity were established by the installation of crab cavities in KEKB. Tune spectra of a colliding bunch in a crabbing collision were observed by using a spectrum analyzer. The beam-beam spectrum showed strong nonlinear resonance. By taking...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
American Physical Society
2009-06-01
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| Series: | Physical Review Special Topics. Accelerators and Beams |
| Online Access: | http://doi.org/10.1103/PhysRevSTAB.12.064401 |
| _version_ | 1818312262176210944 |
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| author | T. Ieiri Y. Ohnishi M. Tobiyama S. Uehara |
| author_facet | T. Ieiri Y. Ohnishi M. Tobiyama S. Uehara |
| author_sort | T. Ieiri |
| collection | DOAJ |
| description | Effective head-on collision and improvement in specific luminosity were established by the installation of crab cavities in KEKB. Tune spectra of a colliding bunch in a crabbing collision were observed by using a spectrum analyzer. The beam-beam spectrum showed strong nonlinear resonance. By taking into account this nonlinearity, the coherent beam-beam tune shift was measured as a function of the bunch current. The vertical beam-beam parameter estimated from the coherent beam-beam tune shift was found to agree with that observed by using a bunch-by-bunch luminosity monitor. The estimated vertical beam-beam parameter is saturated at approximately 0.05; this value is the beam-beam limit. Further, the bunch current corresponding to the beam-beam limit was found to be considerably lower than that used in usual operations. The horizontal beam-beam parameter was not saturated over 0.15. The horizontal beam-beam parameter estimated from the coherent beam-beam tune shift approximately agrees with a calculated beam-beam parameter considering the dynamic beam-beam effect. |
| first_indexed | 2024-12-13T08:15:03Z |
| format | Article |
| id | doaj.art-7fd9aaa94c00454b9c46360ec3f662ec |
| institution | Directory Open Access Journal |
| issn | 1098-4402 |
| language | English |
| last_indexed | 2024-12-13T08:15:03Z |
| publishDate | 2009-06-01 |
| publisher | American Physical Society |
| record_format | Article |
| series | Physical Review Special Topics. Accelerators and Beams |
| spelling | doaj.art-7fd9aaa94c00454b9c46360ec3f662ec2022-12-21T23:54:07ZengAmerican Physical SocietyPhysical Review Special Topics. Accelerators and Beams1098-44022009-06-0112606440110.1103/PhysRevSTAB.12.064401Measurement of coherent beam-beam tune shift under crabbing collision at KEKBT. IeiriY. OhnishiM. TobiyamaS. UeharaEffective head-on collision and improvement in specific luminosity were established by the installation of crab cavities in KEKB. Tune spectra of a colliding bunch in a crabbing collision were observed by using a spectrum analyzer. The beam-beam spectrum showed strong nonlinear resonance. By taking into account this nonlinearity, the coherent beam-beam tune shift was measured as a function of the bunch current. The vertical beam-beam parameter estimated from the coherent beam-beam tune shift was found to agree with that observed by using a bunch-by-bunch luminosity monitor. The estimated vertical beam-beam parameter is saturated at approximately 0.05; this value is the beam-beam limit. Further, the bunch current corresponding to the beam-beam limit was found to be considerably lower than that used in usual operations. The horizontal beam-beam parameter was not saturated over 0.15. The horizontal beam-beam parameter estimated from the coherent beam-beam tune shift approximately agrees with a calculated beam-beam parameter considering the dynamic beam-beam effect.http://doi.org/10.1103/PhysRevSTAB.12.064401 |
| spellingShingle | T. Ieiri Y. Ohnishi M. Tobiyama S. Uehara Measurement of coherent beam-beam tune shift under crabbing collision at KEKB Physical Review Special Topics. Accelerators and Beams |
| title | Measurement of coherent beam-beam tune shift under crabbing collision at KEKB |
| title_full | Measurement of coherent beam-beam tune shift under crabbing collision at KEKB |
| title_fullStr | Measurement of coherent beam-beam tune shift under crabbing collision at KEKB |
| title_full_unstemmed | Measurement of coherent beam-beam tune shift under crabbing collision at KEKB |
| title_short | Measurement of coherent beam-beam tune shift under crabbing collision at KEKB |
| title_sort | measurement of coherent beam beam tune shift under crabbing collision at kekb |
| url | http://doi.org/10.1103/PhysRevSTAB.12.064401 |
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