Paper |
Title |
Page |
MOPLS060 |
Design of an Interaction Region with Head-on Collisions for the ILC
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682 |
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- J. Payet, O. Napoly, C. Rippon, D. Uriot
CEA, Gif-sur-Yvette
- M. Alabau Pons, P. Bambade, J. Brossard, O. Dadoun, C. Rimbault
LAL, Orsay
- D.A.-K. Angal-Kalinin, F. Jackson
CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
- R. Appleby
UMAN, Manchester
- L. Keller, Y. Nosochkov, A. Seryi
SLAC, Menlo Park, California
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An interaction region with head-on collisions is considered an alternative to the baseline configuration of the International Linear Collider, including two interaction regions with finite crossing-angles (2 and 20 mrad). Although more challenging from the point of view of the beam extraction, the head-on scheme is favoured by the experiments because it allows a more convenient detector configuration, particularly in the forward region. The optics of the head-on extraction is revisited by separating the e+ and e- beams horizontally, first by electrostatic separators operated at their LEP nominal field and then using a defocusing quadrupole of the final focus beam line. In this way the septum magnet is protected from the beamstrahlung power. Newly optimized final focus and extraction optics are presented, including a first look at post-collision diagnostics. The influence of parasitic collisions is shown to lead to a region of stable collision parameters. Beam and beamstrahlung photon losses are calculated along the extraction elements. Issues concerning the design of the large bore superconducting final focus magnets, common to both incoming and outgoing beams, are considered.
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MOPLS061 |
Optimization of the e-e- Option for the ILC
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685 |
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- M. Alabau Pons, M. Alabau Pons, A. Faus-Golfe
IFIC, Valencia
- R. Appleby
UMAN, Manchester
- P. Bambade, O. Dadoun
LAL, Orsay
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The e-e- running mode is one of the interesting physics options for the International Linear Collider. The luminosity for e-e- collisions is reduced by mutual defocusing due to the strong electromagnetic fields that the bunches experience during collisions. The resulting beamstrahlung energy loss and beam-beam deflection angles as function of the vertical transverse offset are different compared to the e+e- collisions. In this paper, the dependence of these observables with the offset for different beam sizes has been analysed to optimize performances for the e-e- mode, taking into account the requirements of the beam-beam deflection based intra-train feedback system. A first study of the implications for the final focus and extraction line optics is also presented for the cases of the 2mrad and 20mrad ILC base line crossing angle geometries.
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MOPLS077 |
The 2mrad Crossing Angle Interaction Region and Extraction Line
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730 |
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- R. Appleby
UMAN, Manchester
- D.A.-K. Angal-Kalinin
CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
- P. Bambade, O. Dadoun
LAL, Orsay
- J. Carter
Royal Holloway, University of London, Surrey
- L. Keller, K. C. Moffeit, Y. Nosochkov, A. Seryi, C.M. Spencer
SLAC, Menlo Park, California
- O. Napoly
CEA, Gif-sur-Yvette
- B. Parker
BNL, Upton, Long Island, New York
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A complete optics design for the 2mrad crossing angle interaction region and extraction line was presented at Snowmass 2005. Since this time, the design task force has been working on developing and improving the performance of the extraction line. The work has focused on optimising the final doublet parameters and on reducing the power losses resulting from the disrupted beam transport. In this paper, the most recent status of the 2mrad layout and the corresponding performance are presented.
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MOPLS078 |
Benchmarking of Tracking Codes (BDSIM/DIMAD) using the ILC Extraction Lines
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733 |
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- R. Appleby
UMAN, Manchester
- P. Bambade, O. Dadoun
LAL, Orsay
- A. Ferrari
UU/ISV, Uppsala
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The study of beam transport is of central importance to the design and performance assessment of modern particle accelerators. In this work, we benchmark two contemporary codes - DIMAD and BDSIM, the latter being a relatively new tracking code and built within the framework of GEANT4. We consider both the 20mrad and 2mrad extraction lines of the International Linear Collider and perform disrupted beam tracking studies of heavily disrupted post-collision electron beams. We find that the two codes in most cases give an equivalent description of the beam transport.
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