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

Ross, M.C.

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.
TUPCH024	Comparative Study of Bunch Length and Arrival Time Measurements at FLASH	1049
	H. Schlarb, A. Azima, S. Düsterer, M. Huening, E.-A. Knabbe, M. Roehrs, R. Rybnikov, B. Schmidt, B. Steffen DESY, Hamburg M.C. Ross SLAC, Menlo Park, California P. Schmüser, A. Winter Uni HH, Hamburg
	Diagnostic devices to precisely measure the longitudinal electron beam profile and the bunch arrival time require elaborate new instrumentation techniques. At the VUV-FEL, two entirely different methods are used. The bunch profile can be determined with high precision by a transverse deflecting RF structure. The method is disruptive and does not allow to monitor multiple bunches in a macro-pulse train. Therefore, it is augmented by two non-disruptive electro-optical devices, called EO and TEO. The EO setup uses a dedicated diagnostic laser synchronized to the machine RF. The longitudinal electron beam profile is encoded in the intensity profile of a chirped laser pulse and analyzed by looking at the spectral composition of the pulse. The second setup, TEO, utilizes the TiSa-based laser system used for pump-probe experiments. Here, the temporal electron shape is encoded into a spatial dimension of laser pulse by an intersection angle between the laser and the electron beam at the EO-crystal. In this paper, we present a comparative study of bunch length and arrival time measurements performed simultaneously with all three experimental techniques.
TUPCH048	A Study of Emittance Measurement at the ILC	1115
	G.A. Blair, I.V. Agapov, J. Carter, L. Deacon Royal Holloway, University of London, Surrey D.A.-K. Angal-Kalinin CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire L.J. Jenner Cockcroft Institute, Warrington, Cheshire M.C. Ross, A. Seryi, M. Woodley SLAC, Menlo Park, California
	The measurement of the ILC emittance in the ILC beam delivery system and the linac is simulated. Estimates of statistical and machine-related errors are discussed and implications for related diagnostics R&D are inferred.
THPCH067	Coherent Synchrotron Radiation Studies at the Accelerator Test Facility	2940
	S. De Santis, J.M. Byrd LBNL, Berkeley, California A. Aryshev, T. Naito, J. Urakawa KEK, Ibaraki M.C. Ross SLAC, Menlo Park, California
	Coherent Synchrotron Radiation (CSR) has been the object of recent experiments and is a topic of great importance for several accelerator currently in their design phase (LCLS, ILC, CIRCE). We present the results of several experimental sessions performed at the Advanced Test Facility - KEK (ATF). An infrared bolometer was used to detect the emitted infrared radiation in the 1-0.05 mm wavelength range as a function of several beam parameters (beam current, RF power, extraction timing, photoinjector laser phase). The beam energy spread was also recorded. We found that the mismatch between injected and equilibrium beam is the source of the coherent signal detected concurrently with the bunch injection.
THPCH077	Resistive-wall Instability in the Damping Rings of the ILC	2964
	L. Wang, K.L.F. Bane, T.O. Raubenheimer, M.C. Ross SLAC, Menlo Park, California
	In the damping rings of the International Linear Collider (ILC), the resistive-wall instability is one of the dominant transverse instabilities. This instability directly influences the choice of material and aperture of the vacuum pipe, and the parameters of the transverse feedback system. This paper investigates the resistive-wall instabilities in an ILC damping ring under various conditions of beam pipe material, aperture, and fill pattern.
MOPLS045	Achieving a Luminosity of 10³⁴/cm²/s in the PEP-II B-factory	643
	J. Seeman, J. Browne, Y. Cai, W.S. Colocho, F.-J. Decker, M.H. Donald, S. Ecklund, R.A. Erickson, A.S. Fisher, J.D. Fox, S.A. Heifets, R.H. Iverson, A. Kulikov, A. Novokhatski, V. Pacak, M.T.F. Pivi, C.H. Rivetta, M.C. Ross, P. Schuh, K.G. Sonnad, M. Stanek, M.K. Sullivan, P. Tenenbaum, D. Teytelman, J.L. Turner, D. Van Winkle, M. Weaver, U. Wienands, W. Wittmer, M. Woodley, Y.T. Yan, G. Yocky SLAC, Menlo Park, California M.E. Biagini INFN/LNF, Frascati (Roma) W. Kozanecki CEA, Gif-sur-Yvette
	For the PEP-II Operation Staff: PEP-II is an asymmetric e⁺e^- collider operating at the Upsilon 4S and has recently set several performance records. The luminosity has exceeded 1x10³⁴/cm²/s and has delivered an integrated luminosity of 728/pb in one day. PEP-II operates in continuous injection mode for both beams, boosting the integrated luminosity. The peak positron current has reached 2.94 A and 1.74 A of electrons in 1732 bunches. The total integrated luminosity since turn on in 1999 has reached over 333/fb. This paper reviews the present performance issues of PEP-II and also the planned increase of luminosity in the near future to over 2 x 10³⁴/cm²/s. Upgrade details and plans are discussed.
MOPLS066	Direct Measurement of Geometric and Resistive Wakefields in Tapered Collimators for the International Linear Collider	697
	N.K. Watson, D. Adey, M.C. Stockton Birmingham University, Birmingham D.A.-K. Angal-Kalinin, C.D. Beard, J.L. Fernandez-Hernando, F. Jackson CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire R. Arnold, R.A. Erickson, C. Hast, T.W. Markiewicz, S. Molloy, M.C. Ross, S. Seletskiy, A. Seryi, Z. Szalata, P. Tenenbaum, M. Woodley, M. Woods SLAC, Menlo Park, California R.J. Barlow, A. Bungau, R.M. Jones, G.Yu. Kourevlev, A. Mercer UMAN, Manchester D.A. Burton, J.D.A. Smith, A. Sopczak, R. Tucker Lancaster University, Lancaster C. Densham, G. Ellwood, R.J.S. Greenhalgh, J. O'Dell CCLRC/RAL, Chilton, Didcot, Oxon Y.K. Kolomensky UCB, Berkeley, California M. Kärkkäinen, W.F.O. Müller, T. Weiland TEMF, Darmstadt N. Shales Microwave Research Group, Lancaster University, Lancaster M. Slater University of Cambridge, Cambridge I. Zagorodnov DESY, Hamburg F. Zimmermann CERN, Geneva
	Precise collimation of the beam halo is required in the ILC to prevent beam losses near the interaction region that could cause unacceptable backgrounds for the physics detector. The necessarily small apertures of the collimators lead to transverse wakefields that may result in beam deflections and increased emittance. A set of collimator wakefield measurements has previously been performed in the ASSET region of the SLAC LINAC. We report on the next phase of this programme, which is carried out at the recently commissioned End Station A test facility at SLAC. Measurements of resistive and geometric wakefields using tapered collimators are compared with model predictions from MAFIA and GdfidL and with analytic calculations.
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.
MOPLS080	A Laser-wire System at the ATF Extraction Line	738
	S.T. Boogert, G.A. Blair, G.E. Boorman, A. Bosco, L. Deacon, C. Driouichi Royal Holloway, University of London, Surrey A. Aryshev, H. Hayano, V. Karataev, K. Kubo, N. Terunuma, J. Urakawa KEK, Ibaraki A. Brachmann, J.C. Frisch, M.C. Ross SLAC, Menlo Park, California N. Delerue JAI, Oxford S. Dixit, F.B. Foster, G.F. Gannaway, D.F. Howell, Q.M. Qureshi, A. Reichold, R. Senanayake OXFORDphysics, Oxford, Oxon L.J. Jenner Cockcroft Institute, Warrington, Cheshire T. Kamps BESSY GmbH, Berlin
	A new laser-wire system has been installed at the ATF extraction line at KEK, Tsukuba. The system aims at a micron-scale laser spot size and employs a mode-locked laser system. The purpose-built interaction chamber, light delivery optics, and lens systems are described, and the first results are presented.
MOPLS081	A Study of Laser System Requirements for Application in Beam Diagnostics and Polarimetry at the ILC	741
	S. Dixit, N. Delerue, K.J. Peach JAI, Oxford G.A. Blair, S.T. Boogert, G.E. Boorman, A. Bosco, C. Driouichi Royal Holloway, University of London, Surrey A. Brachmann, J.C. Frisch, M.C. Ross SLAC, Menlo Park, California F.B. Foster, D.F. Howell, Q.G. Quelch, Q.M. Qureshi, A. Reichold OXFORDphysics, Oxford, Oxon G.J. Hirst, I. N. Ross CCLRC/RAL, Chilton, Didcot, Oxon V. Soskov, V. Variola, Z.F. Zomer LAL, Orsay J. Urakawa KEK, Ibaraki
	Advanced laser systems will be essential for a range of diagnostics devices at the ILC. High average power, excellent stability and reliability will be crucial in order to deliver the information required to attain the necessary ILC luminosity. The key parameters are listed together with the R&D required to achieve the necessary laser system performance.
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
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.
THPLS113	Design of a Fast Extraction Kicker for the Accelerator Test Facility	3544
	S. De Santis, A. Wolski LBNL, Berkeley, California M.C. Ross SLAC, Menlo Park, California
	We present a study for the design of a fast extraction kicker to be installed in the Advanced Test Facility ring. The purpose of the project is to test the technologies to be used in the design of the extraction kickers for the ILC damping rings. The kicker's rise and fall times are important parameters in the design of the damping rings, as they limit the minimum distance between bunches and ultimately define a lower boundary for the ring length. We propose a stripline kicker composed of several 20-cm long sections, grouped in two locations in the ATF damping ring. An analytical study of the kicker's parameters and computer simulations using Microwave Studio* point out the strict requirements on the pulsers, in order to be able to satisfy the design parameters. *http://www.cst.com