Napoly, O.

Paper	Title	Page
MOPLS060	Design of an Interaction Region with Head-on Collisions for the ILC	682
	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
	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.
MOPLS077	The 2mrad Crossing Angle Interaction Region and Extraction Line	730
	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
	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.
TUYPA02	High Precision SC Cavity Alignment Diagnostics with HOM Measurements	920
	J.C. Frisch, L. Hendrickson, J. May, D.J. McCormick, S. Molloy, M.C. Ross, T.J. Smith SLAC, Menlo Park, California N. Baboi, O. Hensler, L.M. Petrosyan DESY, Hamburg N.E. Eddy, S. Nagaitsev Fermilab, Batavia, Illinois O. Napoly, R. Paparella, C. Simon CEA, Gif-sur-Yvette
	Experiments at the TTF at DESY have demonstrated that the Higher Order Modes induced in Superconducting Cavities can be used to provide a variety of beam and cavity diagnostics. The centers of the cavities can be determined from the beam orbit which produces minimum power in the dipole HOM modes. The phase and amplitude of the dipole modes can be used as a high resolution beam position monitor, and the phase of the monopole modes to measure the beam phase relative to the accelerator RF. Beam orbit feedback which minimizes the dipole HOM power in a set of structures has been demonstrated. For most SC accelerators, the existing HOM couplers provide the necessary signals, and the downmix and digitizing electronics are straightforward, similar to those for a conventional BPM.
	Transparencies
TUPCH007	High Resolution BPM for the Linear Colliders	1004
	C. Simon, S. Chel, M. Luong, O. Napoly, J. Novo, D. Roudier CEA, Gif-sur-Yvette N. Rouvière IPN, Orsay
	The beam-based alignment and feedback systems which are essential for the operation of the future colliders use some high resolution Beam Position Monitors (BPM). In the framework of CARE/SRF, the task of CEA/DSM/DAPNIA (Saclay) is the design, the fabrication and the beam test of a BPM in collaboration with DESY. This system is composed of a RF re-entrant cavity with a beam pipe radius of 78mm and an analog electronics having several signal processing steps to reject the monopole mode. Thanks to its high position resolution (better than 1μm) and its high time-resolution (around 10ns), it is a candidate for the X-FEL at DESY and the ILC. Indeed the chosen coupling allows the bunch to bunch measurement and the separation between the monopole and dipole modes. Moreover, this BPM is designed to be used in a clean environment, at the cryogenic and room temperatures.