| Paper |
Title |
Page |
| WEPKF080 |
Secondary Electron Yield Measurements from Thin Surface Coatings for NLC Electron Cloud Reduction
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1789 |
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- F. Le Pimpec, F. King, R.E. Kirby, M.T.F. Pivi
SLAC, Menlo Park, California
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In the beam pipe of the positron damping ring of the Next Linear Collider, electrons will be created by beam interaction with the surrounding vacuum chamber wall and give rise to an electron cloud. Several solutions are possible for avoiding the electron cloud, without changing the beam bunch structure or the diameter of the vacuum chamber. Some of the currently available solutions include reducing residual gas ionization by the beam, minimizing photon-induced electron production, and lowering the secondary electron yield (SEY) of the chamber wall. We will report on recent SEY measurements performed at SLAC on TiN coatings and TiZrV non-evaporable getter thin films.
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| WEPKF085 |
Secondary Electron Emission Measurements for TiN Coating on Stainless Steel of SNS Accumulator Ring Vacuum Chamber
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1804 |
| |
- P. He, H.-C. Hseuh, R. Todd
BNL, Upton, Long Island, New York
- B. Henrist, N. Hilleret
CERN, Geneva
- S. Kato, M. Nishiwaki
KEK, Ibaraki
- R.E. Kirby, F. Le Pimpec, M.T.F. Pivi
SLAC, Menlo Park, California
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BNL is responsible for the design and construction of the US Spallation Neutron Source (SNS) accumulator ring. Titanium Nitride(TiN) coating on the stainless steel vacuum chamber of the SNS accumulator ring is needed to reduce undesirable resonant multiplication of electrons. The Secondary Electron Yield(SEY) of TiN coated chamber material has been measured after coated samples were exposed to air and after electron and ion conditioning. We are reporting about the TiN coating system setup at BNL and SEY measurements results performed at CERN, SLAC and KEK. We also present updated electron-cloud simulation results for the SNS accumulator assuming different SEY values.
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| WEPLT157 |
Single-bunch Electron Cloud Effects in the GLC/NLC, US-cold and TESLA Low Emittance Transport Lines
|
2206 |
| |
- M.T.F. Pivi, D. Bates, A. Chang, D. Chen, T.O. Raubenheimer
SLAC, Menlo Park, California
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In the beam pipe of the Beam Delivery System (BDS) and Bunch Compressor system (BCS) of a linear collider, ionization of residual gasses and secondary emission may lead to amplification of an initial electron signal during the bunch train passage and ultimately give rise to an electron-cloud. A positron beam passing through the linear collider beam delivery may experience unwanted additional focusing due to interaction with the electron cloud. This typically leads to an increase in the beam size at the interaction point (IP) when the cloud density is high. Interaction with the electron cloud in the bunch compressor could also potentially cause an instability. This paper examines the severity of the electron cloud effects in the BCS and BDS of both the GLC/NLC and US-Cold linear collider design through the use of specially developed simulation codes. An estimate of the critical cloud density is given for the BDS and BCS of both designs.
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| MOPLT143 |
Results and Plans of the PEP-II B-Factory
|
875 |
| |
- J. Seeman, J. Browne, Y. Cai, S. Colocho, F.-J. Decker, M.H. Donald, S. Ecklund, R.A. Erickson, A.S. Fisher, J.D. Fox, S.A. Heifets, R.H. Iverson, A. Kulikov, A. Novokhatski, M.T.F. Pivi, M.C. Ross, P. Schuh, T.J. Smith, K. Sonnad, M. Stanek, M.K. Sullivan, P. Tenenbaum, D. Teytelman, J.L. Turner, D. Van Winkle, U. Wienands, M. Woodley, Y.T. Yan, G. Yocky
SLAC, Menlo Park, California
- M.E. Biagini
INFN/LNF, Frascati (Roma)
- J.N. Corlett, C. Steier, A. Wolski, M.S. Zisman
LBNL, Berkeley, California
- W. Kozanecki
CEA/DSM/DAPNIA, Gif-sur-Yvette
- G. Wormser
IPN, Orsay
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PEP-II is an e+e- B-Factory Collider located at SLAC operating at the Upsilon 4S resonance. PEP-II has delivered, over the past four years, an integrated luminosity to the BaBar detector of over 175 fb-1 and has reached a luminosity over 7.4x1033/cm2/s. Steady progress is being made in reaching higher luminosity. The goal over the next few years is to reach a luminosity of at least 2x1034/cm2/s. The accelerator physics issues being addressed in PEP-II to reach this goal include the electron cloud instability, beam-beam effects, parasitic beam-beam effects, trickle injection, high RF beam loading, lower beta y*, interaction region operation, and coupling control.
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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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| THPLT159 |
Instability Thresholds and Generation of the Electron-cloud in the GLC/NLC and Tesla Damping Rings
|
2828 |
| |
- M.T.F. Pivi, T.O. Raubenheimer
SLAC/NLC, Menlo Park, California
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In the beam pipe of the Damping Ring (DR) of a linear collider, an electron cloud may be produced by ionization of residual gas and secondary emission. This electron cloud can reach equilibrium after the passage of only a few bunches. We present recent computer simulation results for the main features of the electron cloud generation in the GLC/NLC main DR and for the TESLA DR. Single and multi-bunch instability thresholds are also calculated for the NLC main DR. The results are obtained by the computer simulation codes HEAD-TAIL and POSINST, which were developed to study the electron cloud effect in particle accelerators.
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