| Paper |
Title |
Page |
| TUPLT078 |
Study of Impedances and Instabilities in J-PARC
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1336 |
| |
- T. Toyama, K. Ohmi
KEK, Ibaraki
- Y. Shobuda
JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
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J-PARC consists of two high intensity proton rings with energies of 3 GeV and 50 GeV. Longitudinal impedances and instabilities, which are caused by beam chamber, cavities, kicker magnets and others, are mainly discussed in this paper.
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| WEPLT054 |
Electron Cloud Build up in Coasting Beams
|
1960 |
| |
- G. Rumolo
GSI, Darmstadt
- G. Bellodi
CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
- K. Ohmi
KEK, Ibaraki
- F. Zimmermann
CERN, Geneva
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Electrons could in principle accumulate in the potential of coasting beams of positively charged particles until a balance between the beam force and space charge force from the electrons is reached. But the continuous interaction between a non-ideal perturbed coasting beam and the cloud of electrons being trapped by it, together with the reflection and secondary emission processes at the inner pipe wall, can alter this picture and cause a combined cloud or beam transverse instability long before the concentration of electrons reaches the theoretical equilibrium value. The issue is addressed in this paper by means of combined build-up and instability simulations carried out with the HEADTAIL code.
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| WEPLT108 |
Diffusion caused by Beam-beam Interactions with Couplings
|
2101 |
| |
- K. Ohmi, S. Kamada, K. Oide, M. Tawada
KEK, Ibaraki
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A system of colliding two beams is strong nonlinear in multi-dimension. In such a system, a symplectic diffusion called Arnold diffusion occurs, with the result that the beams are enlarged and the luminosity is degraded in circular colliders. We discuss the diffusion seen in beam-beam inetraction at a circular accelerator, especially finite crossing angle and/or x-y coupling errors enhance the diffusion.
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| WEPLT109 |
Simulation of Ep Instability for a Coasting Proton Beam in Circular Accelerators
|
2104 |
| |
- K. Ohmi, T. Toyama
KEK, Ibaraki
- G. Rumolo
GSI, Darmstadt
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ep instability is discussed for a coasting beam operation of J-PARC 50 GeV Main Ring. Our previous study (PAC2003) was focussed only ionization electron. We now take into account electrons created at the chamber wall due to proton loss and secondary emission with higher yield than ionization.
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| MOPLT067 |
KEKB Performance
|
707 |
| |
- Y. Funakoshi, K. Akai, K. Ebihara, K. Egawa, A. Enomoto, J. Flanagan, H. Fukuma, K. Furukawa, T. Furuya, J. Haba, S. Hiramatsu, T. Ieiri, N. Iida, H. Ikeda, T. Kageyama, S. Kamada, T. Kamitani, S. Kato, M. Kikuchi, E. Kikutani, H. Koiso, M. Masuzawa, T. Mimashi, A. Morita, T. Nakamura, H. Nakayama, Y. Ogawa, K. Ohmi, Y. Ohnishi, N. Ohuchi, K. Oide, M. Shimada, S. Stanic, M. Suetake, Y. Suetsugu, T. Sugimura, T. Suwada, M. Tawada, M. Tejima, M. Tobiyama, S. Uehara, S. Uno, S.S. Win, N. Yamamoto, Y. Yamamoto, Y. Yano, K. Yokoyama, M. Yoshida, M. Yoshida, S.I. Yoshimoto
KEK, Ibaraki
- F. Zimmermann
CERN, Geneva
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The KEKB B-Factory is an electron-positron double ring collider working at KEK. Its peak luminosity surpassed 1034 /cm2/sec in May 2003 for the first time in the history of colliders. In this report, we summarize the history of KEKB with an emphasis of recent progress.
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| THPLT017 |
Review and Comparison of Simulation Codes Modeling Electron-Cloud Build Up and Instabilities
|
2499 |
| |
- F. Zimmermann, E. Benedetto, F. Ruggiero, D. Schulte
CERN, Geneva
- G. Bellodi
CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
- M. Blaskiewicz, L. Wang
BNL, Upton, Long Island, New York
- Y. Cai, M.T.F. Pivi
SLAC, Menlo Park, California
- V.K. Decyk, W. Mori
UCLA, Los Angeles, California
- M.A. Furman
LBNL/AFR, Berkeley, California
- A.F. Ghalam, T. Katsouleas
USC, Los Angeles, California
- K. Ohmi, S.S. Win
KEK, Ibaraki
- G. Rumolo
GSI, Darmstadt
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Several computer codes written at various laboratories are employed for modelling the generation and the consequences of an electron cloud. We review the most popular of these programs, which simulate either the build of an electron cloud or the instabilities it produces, and we compare simulation results for identical, or similar, input parameters obtained from the various codes.
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