EPAC 2006 - List of Authors

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

White, G.R.

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.
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.
THPCH089	The Electromagnetic Background Environment for the Interaction-point Beam Feedback System at the International Linear Collider	2997
	G.B. Christian, P. Burrows, G.B. Christian, C.C. Clarke, A.F. Hartin, C. Swinson, G.R. White OXFORDphysics, Oxford, Oxon R. Arnold, C. Hast, S. Smith, M. Woods SLAC, Menlo Park, California A. Kalinin CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
	The Interaction Point (IP) feedback system is essential for maintaining the luminosity at the International Linear Collider (ILC). It is necessary to demonstrate the performance of the feedback beam position monitor (BPM) in an electron-positron pair background similar to that expected in the ILC interaction region (IR). We have simulated the ILC beam-beam interactions and used a GEANT model of the IR to evaluate the pair and photon flux incident on the BPM, for both the 2 mrad and 20 mrad crossing angle geometries. We present results as a function of the proposed machine parameter schemes, as well as for various system layouts within the IR. We plan to study the degradation of BPM resolution, and the long term survivability, in beam tests at End Station A at SLAC. To simulate the background environment of the ILC a 'spray beam' will be produced, which will scatter from a mechanical mock-up of the forward region of the IR, and irradiate the BPM with realistic flux of secondary pairs. We present the proposed experimental layout and planned beam tests.
THPCH104	Design and Simulation of the ILC Intra-train Orbit and Luminosity Feedback Systems	3041
	G.R. White, G.R. White JAI, Oxford D. Schulte CERN, Geneva N.J. Walker DESY, Hamburg
	To maintain luminosity to within a few percent of the design at the International Linear Collider (ILC), beam stability at the IP needs to be maintained at the sub-nanometre level. To achieve the beam stability required in the presence of ground motion, multiple feedback systems are required. The baseline design calls for a 5-Hz system to control the orbit in the Linac and Beam Delivery System (BDS) and an intra-train system to address high-frequency ground motion and mechanical disturbances which cause orbit distortions at the IP between pulses enough to completely destroy the luminosity. Details of the slower feedback systems have been addressed elsewhere. The detailed design and simulation of the intra-train feedback systems are described here. This system controls the vertical position and angle at the IP such that luminosity is maximised. The system brings the beams into collision based on BPM-derived information from the initial bunches of the train. It then tunes the IP collision parameters (both position and angle) based on a fast (bunch-by-bunch) luminosity signal from the BeamCal. The system is implemented in fast digital FPGA logic, designed using Matlab's Simulink. A. Seryi et al. "Issues of Stability and Ground Motion in ILC", Nanobeam 2005.**G. White et al. "Multi-Bunch Simulations of the ILC for Luminosity Performance Studies", PAC2005.
THPCH104	Design and Simulation of the ILC Intra-train Orbit and Luminosity Feedback Systems	3041
	G.R. White, G.R. White JAI, Oxford D. Schulte CERN, Geneva N.J. Walker DESY, Hamburg
	To maintain luminosity to within a few percent of the design at the International Linear Collider (ILC), beam stability at the IP needs to be maintained at the sub-nanometre level. To achieve the beam stability required in the presence of ground motion, multiple feedback systems are required. The baseline design calls for a 5-Hz system to control the orbit in the Linac and Beam Delivery System (BDS) and an intra-train system to address high-frequency ground motion and mechanical disturbances which cause orbit distortions at the IP between pulses enough to completely destroy the luminosity. Details of the slower feedback systems have been addressed elsewhere. The detailed design and simulation of the intra-train feedback systems are described here. This system controls the vertical position and angle at the IP such that luminosity is maximised. The system brings the beams into collision based on BPM-derived information from the initial bunches of the train. It then tunes the IP collision parameters (both position and angle) based on a fast (bunch-by-bunch) luminosity signal from the BeamCal. The system is implemented in fast digital FPGA logic, designed using Matlab's Simulink. A. Seryi et al. "Issues of Stability and Ground Motion in ILC", Nanobeam 2005.**G. White et al. "Multi-Bunch Simulations of the ILC for Luminosity Performance Studies", PAC2005.