Paper |
Title |
Page |
THPCH075 |
Simulation of the Electron Cloud for Various Configurations of a Damping Ring for the ILC
|
2958 |
|
- M.T.F. Pivi, T.O. Raubenheimer, L. Wang
SLAC, Menlo Park, California
- K. Ohmi
KEK, Ibaraki
- R. Wanzenberg
DESY, Hamburg
- A. Wolski
Liverpool University, Science Faculty, Liverpool
- F. Zimmermann
CERN, Geneva
|
|
|
In the beam pipe of the Damping Ring (DR) of the International Linear Collider (ILC), an electron cloud may be first produced by photoelectrons and ionization of residual gasses and then increased by the secondary emission process. This paper reports about the work that has been done by the electron cloud assessment international task force group for the recommendation of the ILC Damping Rings baseline design, made in November 2005. We have carefully estimated the secondary electron yield (SEY) threshold for electron cloud build-up and estimated the related single- and coupled-bunch instabilities that can be caused by the presence of electron cloud as a function of beam current and surface properties, for a variety of optics designs. The result of these studies was an important consideration in the choice of a 6-km design for the ILC damping rings. On the basis of the theoretical and experimental work, the baseline configuration specifies a pair of damping rings for the positron beam to mitigate the effects of the electron cloud.
|
|
THPLS023 |
Wake Computations for the Beam Positioning Monitors of PETRA III
|
3326 |
|
- A.K. Bandyopadhyay, A. Joestingmeier, A.S. Omar
Otto-Von-Guericke University, Magdeburg
- K. Balewski, R. Wanzenberg
DESY, Hamburg
|
|
|
At DESY it is planned to convert the PETRA ring into a synchrotron radiation facility, called PETRA III, in 2007. For proper design of PETRA III it is very important to estimate the wakes due to various discontinuities along the beam pipe. This article is on the wake computations for the beam positioning monitors (BPMs) in the PETRA III beam pipe. Two computer codes, namely MAFIA and Microwave Studio, were used for the electromagnetic field computations. Convergence tests and the agreement between the results of both softwares were taken as criteria in order to validate the results.
|
|