Paper | Title | Page |
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WEXAB01 | ILC Reference Design and Challenges | 1944 |
The International Linear Collider (ILC) is a 500 GeV center-of-mass electron-positron linear collider based on 1.3 GHz superconducting rf. For the past two years, the ILC design has been developed by an international collaboration, the Global Design Effort. A draft Reference Design Report (RDR) for the ILC was released in February 2007 and, after international review, the final draft will be published in mid-July, 2007. This talk will describe the ILC design along with the outstanding R&D and engineering challenges. The next step is to complete an Engineering Design (EDR) by 2010, and plans for this phase will also be discussed. | ||
WEOAC01 | Secondary Electron Yield and Rectangular Groove Chamber Tests in PEP-II | 1997 |
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Funding: Work supported by the Director, Office of Science, High Energy Physics, U. S. DOE under Contract No. DE-AC02-76SF00515. Possible remedies for the electron cloud in the Damping Ring of the International Linear collider includes conditioning of the surface and chamber with grooves. We installed chambers in PEP-II to test the secondary electron yield (SEY) of coated TiN and TiZrV NEG samples and study the effect of electron and photon conditioning in situ. We have also installed vacuum chambers with rectangular groove profile in straight sections to test this possible mitigation technique. In this paper, we will describe the PEP-II test layout, results and impact on impedance. |
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WEOCAB01 | Design of the Beam Delivery System for the International Linear Collider | 1985 |
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The beam delivery system for the linear collider focuses beams to nanometer sizes at the interaction point, collimates the beam halo to provide acceptable background in the detector and has a provision for state-of-the art beam instrumentation in order to reach the physics goals. The beam delivery system of the International Linear Collider has undergone several configuration changes recently. This paper describes the design details and status of the baseline configuration considered for the reference design. | ||
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THPAN075 | Modeling Incoherent Electron Cloud Effects | 3393 |
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Incoherent effects driven by an electron cloud could seriously limit the beam lifetime in proton storage rings or blow up the vertical emittance in positron ones. Different approaches to modeling these effects each have their own merits and drawbacks. We compare the simulation results and computing time requirements from a number of dedicated codes under development over the last years, and describe the respective approximations for the beam-electron cloud interaction, the accelerator structure, and the optical lattice, made in each of these codes. Examples considered include the LHC, CERN SPS, RHIC, and the ILC damping ring. Tentative conclusions are drawn and a strategy for further codes development is outlined. | ||
FRPMS079 | SUPPRESSION OF SECONDARY ELECTRON EMISSION USING TRIANGULAR GROOVED SURFACE IN THE ILC DIPOLE AND WIGGLER MAGNETS | 4234 |
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Funding: Work supported by the U. S. Department of Energy under contract DE-AC02-76SF00515
The development of an electron cloud in the vacuum chambers of high intensity positron and proton storage rings may limit machine performance. The suppression of electrons in a magnet is a challenge for the positron damping ring of the International Linear Collider (ILC) as well as the Large Hadron Collider. Simulation show that grooved surfaces can significantly reduce the electron yield in a magnet. Some of the secondary electrons emitted from the grooved surface return to the surface within a few gyrations, resulting in a low effective secondary electron yield (SEY) of below 1.0 A triangular surface is an effective, technologically attractive mitigation with a low SEY and a weak dependence on the scale of the corrugations and the external magnetic field. A chamber with triangular grooved surface is proposed for the dipole and wiggler sections of the ILC and will be tested in PEP-II in 2007. The strategy of electron cloud control in ILC and the optimization of the grooved chamber such as the SEY, impedance as well as the manufacturing of the chamber, are also discussed.
SLAC-PUB-11933 & NIMA in publication |
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FRPMS080 | Simulation of the Beam-Ion Instability in the Electron Damping Ring of the International Linear Collider | 4240 |
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Funding: Work supported by the U. S. Department of Energy under contract DE-AC02-76SF00515 Ion induced beam instability is one critical issue for the electron damping ring of the International Linear Collider (ILC) due to its ultra small emittance of 2pm. Bunch train filling pattern is proposed to mitigate the instability and bunch-by-bunch feedback is applied to suppress it. Multi-bunch train fill pattern is introduced in the electron beam to reduce the number of trapped ions. Our study shows that the ion effects can be significantly mitigated by using multiple gaps. However, the beam can still suffer from the beam-ion instability driven by the accumulated ions that cannot escape from the beam during the gaps. The effects of beam fill pattern, emittance, vacuum and various damping mechanism are studied using self-consistent program, which includes the optics of the ring. |