| Paper | Title | Page |
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| MOPP031 | Challenges and Concepts for Design of an Interaction Region with Push-pull Arrangement of Detectors - an Interface Document | 616 |
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| Two experimental detectors working in a push-pull mode has been considered for the Interaction Region of the International Linear Collider [1]. The push-pull mode of operation sets specific requirements and challenges for many systems of detector and machine, in particular for the IR magnets, for the cryogenics system, for alignment system, for beamline shielding, for detector design and overall integration, and so on. These challenges and the identified conceptual solutions discussed in the paper intend to form a draft of the Interface Document which will be developed further in the nearest future. The authors of the present paper include the organizers and conveners of working groups of the workshop on engineering design of interaction region IRENG07 [2], the leaders of the IR Integration within Global Design Effort Beam Delivery System, and the representatives from each detector concept submitting the Letters Of Intent. | ||
| MOPP047 | Simulation Studies on the Vertical Emittance Growth at the Existing ATF Extraction Beamline | 652 |
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Significant dependence of the vertical emittance growth on the beam intensity was experimentally observed at the Accelerator Test Facility (ATF) at KEK extraction beamline. This technical note describes the simulations of possible vertical emittance growth sources, particularly in the extraction channel, where the magnets are shared by both the ATF extraction beamline and its damping ring. The vertical emittance growth is observed in the simulations by changing the beam orbit in the extraction channel, even with all optics corrections. The possible reasons for the experimentally observed dependence of the vertical emittance growth on the beam intensity are discussed. An experiment to measure the emittance versus beam orbit at the existing ATF extraction beamline is underway*.
*M. Alabau et al. Study of Abnormal Vertical Emittance Growth in ATF Extraction Line, this proceeding. |
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| TUPP016 | A Flight Simulator for ATF2 - A Mechanism for International Collaboration in the Writing and Deployment of Online Beam Dynamics Algorithms | 1562 |
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| The goals of ATF2 are to test a novel compact final focus optics design with local chromaticity correction intended for use in future linear colliders. The newly designed extraction line and final focus system will be used to produce a 37nm vertical waist from an extracted beam from the ATF ring of ~30nm vertical normalised emittance, and to stabilise it at the IP-waist to the ~2nm level. Static and dynamic tolerances on all accelerator components are very tight; the achievement of the ATF2 goals is reliant on the application of multiple high-level beam dynamics algorithms to align and tune the electron beam in the extraction line and final focus system. Much algorithmic development work has been done in Japan and by colleagues in collaborating nations in North America and Europe. We describe here development work towards realising a 'flight simulator' environment for the shared development and implementation of beam dynamics code. This software exists as a 'middle-layer' between the lower-level control systems (EPICS and V-SYSTEM) and the multiple higher-level beam dynamics modeling tools in use by the three regions (SAD, Lucretia and PLACET). | ||
| WEPD036 | Radiation and Thermal Analysis of Superconducting Quadrupoles in the Interaction Region of Linear Collider | 2488 |
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| The upcoming and disrupted electron and positron beams in the baseline design of ILC interaction region are focused by compact FD doublets each consisting of two small-aperture superconducting quadrupoles and multipole correctors. These magnets will work in a severe radiation environment generated primarily by incoherent pairs and radiative Bhabhas. This paper analyzes the radial, azimuthal and longitudinal distributions of radiation heat deposition in incoming and disrupted beam doublets. Operation margins of baseline quadrupoles based on NbTi superconductor and direct wind technology as well as alternative designs based on NbTi or Nb3Sn Rutherford cables are calculated and compared. The possibilities of reducing the heat deposition in magnet coils using internal absorbers are discussed. | ||
| WEPP097 | Simulation of Wakefield Effect in ILC IR Chamber | 2743 |
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| To achieve super high luminosity, high current beams with very short bunch length are needed, which carry high intensity EM fields. For ILC, two bunch trains with bunch length of 300μm and bunch charge of 3.2nC are needed to collide at the IR to achieve the ILC luminosity goals. When the 300μm bunches pass through the IR chamber, wakefields will be excited, which will cause HOM power flowing through the IR chamber beam pipe to the final doublets due to the high frequency characteristic of the induced wakefields. Since superconducting technology is adopted for the final doublets of ILC BDS, whose operation stability might be affected by the HOM power produced at the IR chamber, quench might happen. In this paper, we did some analytical estimation and numerical simulation on the wakefield effects in ILC IR chamber. |