McCormick, D.J.

Paper	Title	Page
MOPLS122	Design of the ILC Prototype FONT4 Digital Intra-train Beam-based Feedback System	849
	P. Burrows Queen Mary University of London, London G.B. Christian, H. Dabiri Khah, A.F. Hartin, G.R. White JAI, Oxford C.C. Clarke, C. Perry OXFORDphysics, Oxford, Oxon A. Kalinin CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire D.J. McCormick, S. Molloy, M.C. Ross SLAC, Menlo Park, California
	We report on the design and initial testing of the 4th generation Feedback on Nanosecond Timescales (FONT) prototype intra-train beam-based feedback system for beam control and luminosity optimisation at the International Linear Collider (ILC). FONT4 comprises a fast-analogue front-end BPM signal processor, with an FPGA-based digital feedback processor and a fast-risetime kicker-driver amplifier. The system is being designed with a total latency budget (including signal propagation delays) of about 140ns. FONT4 will be deployed at the Accelerator Test Facility (ATF) at KEK, where it will be tested with the electron bunchtrain extracted from the ATF damping ring. The bunches will have a spacing of c. 150ns, chosen to match the ILC design. We report the results of initial beam tests of the system components. We aim to demonstrate feedback, with delay-loop operation, on this ILC-like bunchtrain.
MOPLS123	Performance of the FONT3 Fast Analogue Intra-train Beam-based Feedback System at ATF	852
	P. Burrows Queen Mary University of London, London G.B. Christian, A.F. Hartin, H.D. Khah, G.R. White JAI, Oxford C.C. Clarke, C. Perry OXFORDphysics, Oxford, Oxon A. Kalinin CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire D.J. McCormick, S. Molloy, M.C. Ross SLAC, Menlo Park, California
	We report on the design and testing of the 3rd generation Feedback On Nanosecond Timescales (FONT) prototype intra-train beam-based feedback system for beam control and luminosity optimisation at the International Linear Collider (ILC). The all-analogue FONT3 electronics was designed to have an ultra-short latency of c. 10ns. We describe the design of the BPM signal processor, feedback circuit and kicker-driver amplifier. We report on deployment of FONT3 at the Accelerator Test Facility (ATF) at KEK, where it was tested with the 56ns-long electron bunchtrain extracted from the ATF damping ring. Feedback, with delay-loop operation, on the beam was demonstrated with a latency close to design. We comment on the applicability of this technology to ILC, as well as future warm-RF based linear colliders, such as CLIC.
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
MOPLS067	Test Beam Studies at SLAC's End Station A, for the International Linear Collider	700
	M. Woods, C. Adolphsen, R. Arnold, G.B. Bowden, G.R. Bower, R.A. Erickson, H. Fieguth, J.C. Frisch, C. Hast, R.H. Iverson, Z. Li, T.W. Markiewicz, D.J. McCormick, S. Molloy, J. Nelson, M.T.F. Pivi, M.C. Ross, S. Seletskiy, A. Seryi, S. Smith, Z. Szalata, P. Tenenbaum SLAC, Menlo Park, California D. Adey, M.C. Stockton, N.K. Watson Birmingham University, Birmingham M. Albrecht, M.H. Hildreth Notre Dame University, Notre Dame, Iowa W.W.M. Allison, V. Blackmore, P. Burrows, G.B. Christian, C.C. Clarke, G. Doucas, A.F. Hartin, B. Ottewell, C. Perry, C. Swinson, G.R. White OXFORDphysics, Oxford, Oxon D.A.-K. Angal-Kalinin, C.D. Beard, J.L. Fernandez-Hernando, F. Jackson, A. Kalinin CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire R.J. Barlow, A. Bungau, G.Yu. Kourevlev, A. Mercer UMAN, Manchester S.T. Boogert Royal Holloway, University of London, Surrey D.A. Burton, J.D.A. Smith, R. Tucker Lancaster University, Lancaster W.E. Chickering, C.T. Hlaing, O.N. Khainovski, Y.K. Kolomensky, T. Orimoto UCB, Berkeley, California C. Densham, R.J.S. Greenhalgh CCLRC/DL, Daresbury, Warrington, Cheshire V. Duginov, S.A. Kostromin, N.A. Morozov JINR, Dubna, Moscow Region G. Ellwood, P.G. Huggard, J. O'Dell CCLRC/RAL, Chilton, Didcot, Oxon F. Gournaris, A. Lyapin, B. Maiheu, S. Malton, D.J. Miller, M.W. Wing UCL, London M.B. Johnston University of Oxford, Clarendon Laboratory, Oxford M.F. Kimmitt University of Essex, Physics Centre, Colchester H.J. Schriber, M. Viti DESY Zeuthen, Zeuthen N. Shales, A. Sopczak Microwave Research Group, Lancaster University, Lancaster N. Sinev, E.T. Torrence University of Oregon, Eugene, Oregon M. Slater, M.T. Thomson, D.R. Ward University of Cambridge, Cambridge Y. Sugimoto KEK, Ibaraki S. Walston LLNL, Livermore, California T. Weiland TEMF, Darmstadt M. Wendt Fermilab, Batavia, Illinois I. Zagorodnov DESY, Hamburg F. Zimmermann CERN, Geneva
	The SLAC Linac can deliver to End Station A a high-energy test beam with similar beam parameters as for the International Linear Collider for bunch charge, bunch length and bunch energy spread. ESA beam tests run parasitically with PEP-II with single damped bunches at 10Hz, beam energy of 28.5 GeV and bunch charge of (1.5-2.0)·1010 electrons. A 5-day commissioning run was performed in January 2006, followed by a 2-week run in April. We describe the beamline configuration and beam setup for these runs, and give an overview of the tests being carried out. These tests include studies of collimator wakefields, prototype energy spectrometers, prototype beam position monitors for the ILC Linac, and characterization of beam-induced electro-magnetic interference along the ESA beamline.
TUPCH105	Performance of a Nanometer Resolution BPM System	1256
	S. Walston, C.C. Chung, P. Fitsos, J.G. Gronberg LLNL, Livermore, California S.T. Boogert Royal Holloway, University of London, Surrey J.C. Frisch, J. May, D.J. McCormick, M.C. Ross, S. Smith, T.J. Smith SLAC, Menlo Park, California H. Hayano, Y. Honda, N. Terunuma, J. Urakawa KEK, Ibaraki Y.K. Kolomensky, T. Orimoto UCB, Berkeley, California A. Lyapin, S. Malton, D.J. Miller UCL, London R. Meller Cornell University, Department of Physics, Ithaca, New York M. Slater, M.T. Thomson, D.R. Ward University of Cambridge, Cambridge V.V. Vogel DESY, Hamburg G.R. White OXFORDphysics, Oxford, Oxon
	International Linear Collider (ILC) interaction region beam sizes and component position stability requirements will be as small as a few nanometers. It is important to the ILC design effort to demonstrate that these tolerances can be achieved – ideally using beam-based stability measurements. It has been estimated that RF cavity beam position monitors (BPMs) could provide position measurement resolutions of less than one nanometer and could form the basis of the desired beam-based stability measurement. We have developed a high resolution RF cavity BPM system. A triplet of these BPMs has been installed in the extraction line of the KEK Accelerator Test Facility (ATF) for testing with its ultra-low emittance beam. The three BPMs are rigidly mounted inside an alignment frame on variable-length struts which allow movement in position and angle. We have developed novel methods for extracting the position and tilt information from the BPM signals including a calibration algorithm which is immune to beam jitter. To date, we have been able to demonstrate a resolution of approximately 20 nm over a dynamic range of ± 20 microns. We report on the progress of these ongoing tests.