Ducimetière, Laurent Advances of Transmission line kicker magnets Fast pulsed magnets or kickers are widely used in circular accelerators for injection, fast extraction and beam excitation. As from the early 60’s transmission line type kicker magnets have been employed to produce rectangular field pulses with good rise time. Over some 40 years this technology has evolved with the rising requirements. While the necessary kick strength has increased with the particle beam energy the strive for efficiency has pushed developments towards lower impedance systems and/or short circuited magnets. The flat top ripple is constrained by the maximally tolerable beam oscillation. The beam intensity can impose a screening of the magnet yoke. The most advanced features implemented in recent transmission line kicker magnets are reviewed and illustrated with examples from different laboratories. eng 2005

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=ab-2005-023; https://accelconf.web.cern.ch/p05/PAPERS/ROAB002.PDF; http://cds.cern.ch/record/844010/files/ab-2005-023.pdf;

Imported from Invenio. Gaxiola, Enrique Bertin, Joel Caspers, Friedhelm Ducimetière, Laurent Kroyer, Tom Experience with Kicker Beam Coupling Reduction Techniques SPS beam impedance is still one of the worries for operation with nominal LHC beam over longer periods, once the final configuration will be installed in 2006. Several CERN SPS kickers suffer from significant beam induced ferrite heating. In specific cases, for instance beam scrubbing, the temperature of certain ferrite yokes went beyond the Curie point. Several retrofit impedance reduction techniques have been investigated theoretically and with practical tests. We report on experience gained during the 2004 SPS operation with resistively coated ceramic inserts in terms of kicker heating, pulse rise time, operating voltage, and vacuum behaviour. For another technique using interleaved metallic stripes we observed significant improvements in bench measurements. Advantages and drawbacks of both methods and potential combinations of them are discussed and simulation as well as measured data are shown. Prospects for further improvements beyond 2006 are briefly outlined. eng 2005

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=ab-2005-024; https://accelconf.web.cern.ch/p05/PAPERS/FPAT021.PDF; http://cds.cern.ch/record/844011/files/ab-2005-024.pdf;

Imported from Invenio. Gaxiola, Enrique Arduini, Gianluigi Höfle, Wolfgang Roncarolo, Federico Vogel, Elmar Vossenberg, Eugène B Performance of the CERN SPS Fast Extraction for the CNGS Facility The SPS LSS4 fast extraction system will serve both the anti-clockwise ring of the LHC and the long baseline neutrino (CNGS) facility. For the latter two extractions spaced by 50 ms, each affecting half of the SPS, are foreseen. During the shutdown 2003-2004 the performance of the fast extraction kickers has been improved in order to match more closely the specifications required for the CNGS and LHC extractions. The kick rise and fall times were significantly reduced, as well as the post-pulse kick ripple. However, the latter remained outside specifications and oscillations were induced in the leading bunches of the batch remaining in the machine at the moment of the first extraction. While further improving the kicker pulse shape, the possibility of damping the beam oscillations using the transverse feedback system has been explored. Recent pulse improvements and results of beam tests are reported. eng 2005

http://documents.cern.ch/cgi-bin/setlink?base=generic&categ=public&id=cer-002527638; https://accelconf.web.cern.ch/p05/PAPERS/FPAT022.PDF; http://cds.cern.ch/record/844014/files/cer-002527638.pdf;

Imported from Invenio. Shaposhnikova, Elena Bohl, T Linnecar, Trevor Paul R Beam transfer functions and beam stabilisation in a double RF system The high intensity proton beam for LHC accelerated in the CERN SPS is stabilised against coupled-bunch instabilities by a 4th harmonic RF system in bunch-shortening mode. Bunch-lengthening mode, which could also be useful to reduce peak line density and alleviate problems from e-cloud and kicker heating, does not give desirable results for beam stability. In this paper an analysis of the limitations of these two different modes of operation is presented together with measurements of the Beam Transfer Function for the double RF system. As predicted by theory, for sufficiently long bunches with the same noise excitation, the measured amplitude of the beam response in bunchlengthening mode is an order of magnitude higher than that for bunch-shortening mode or for a single RF system. eng 2005

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=ab-2005-026; https://accelconf.web.cern.ch/p05/PAPERS/MPPP033.PDF; http://cds.cern.ch/record/844026/files/ab-2005-026.pdf;

Imported from Invenio. Kroyer, Tom Caspers, Friedhelm Mahner, Edgar The CERN-SPS Experiment on Microwave Transmission through the Beam Pipe In the CERN SPS microwave transmission measurements through beampipe sections with a length of 30 m and 7 m respectively have been carried out in the frequency range 2-4 GHz since spring 2003. Here we report on new results obtained with improved measurement techniques during the 2004 run. Observation techniques include a fast real time scope, spectrum analyser IF and video output signal registration and baseband signal observation using a PC soundcard. The unexpected beamâ€"induced amplitude modulation has been confirmed on all kinds of available beams including single bunches. It was found that there is a correlation between the amount of beam induced signal attenuation and the beam losses registered by external scintillators. Potential theoretical models are discussed. eng 2005

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=ab-2005-027; https://accelconf.web.cern.ch/p05/PAPERS/MPPP031.PDF; http://cds.cern.ch/record/844027/files/ab-2005-027.pdf;

Imported from Invenio. Napoly, Olivier Aleksan, Roy den Ouden, Andres Devred, Arnaud Garoby, Roland Garvey, Terence Ghigo, Andrea Gschwendtner, Edda Losito, Roberto Mais, Helmut Palladino, V Proch, Dieter Richard, F Rinolfi, Louis Ruggiero, Francesco Scandale, Walter Schulte, Daniel Vretenar, Maurizio The CARE accelerator R&D programme in Europe CARE, an ambitious and coordinated programme of accelerator research and developments oriented towards high energy physics projects, has been launched in January 2004 by the main European laboratories and the European Commission. This project aims at improving existing infrastructures dedicated to future projects such as linear colliders, upgrades of hadron colliders and high intensity proton drivers. We describe the CARE R&D plans, mostly devoted to advancing the performance of the superconducting technology, both in the fields of RF cavities for electron or proton acceleration and of high field magnets, as well as to developing high intensity electron and proton injectors. We highlight some results and progress obtained so far. eng 2005

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=ab-2005-028; https://accelconf.web.cern.ch/p05/PAPERS/RPPE001.PDF; http://documents.cern.ch/archive/electronic/other/uploader/CARE/Conf/care-conf-05-003.pdf; http://cds.cern.ch/record/844029/files/ab-2005-028.pdf; http://cds.cern.ch/record/844029/files/care-conf-05-003.pdf;

Imported from Invenio. Shaposhnikova, Elena Arduini, Gianluigi Bohl, T Chanel, Michel Garoby, Roland Hancock, Steven Hanke, Klaus Linnecar, Trevor Paul R Steerenberg, R Vandorpe, Bernard Recent intensity increase in the CERN accelerator chain Future requests for protons from the physics community at CERN, especially after the start-up of the CNGS experiments in 2006, can only be satisfied by a substantial increase in the SPS beam intensity per pulse. In September 2004 a three-week beam run was dedicated to high intensity; all accelerators in the chain were pushed to their limits to study intensity restrictions and find possible solutions. New record intensities were obtained in the accelerators of the PS & SPS Complex with this type of beam which is different from the nominal LHC beam. The challenges in producing this high-intensity beam are described, together with the measures needed to make it fully operational. eng 2005

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=ab-2005-029; https://accelconf.web.cern.ch/p05/PAPERS/ROPC004.PDF; http://cds.cern.ch/record/844030/files/ab-2005-029.pdf;

Imported from Invenio. Wuensch, Walter Achard, Claude Braun, Hans Heinrich Carron, Georges Corsini, Roberto Grudiev, Alexei Heikkinen, Samuli Tapio Schulte, Daniel Sladen, Jonathan P H Syratchev, Igor V Tecker, Frank A Wilson, Ian H 30 GHz Power Production in CTF3 One of the major objectives of CTF3 (CLIC Test Facility) is the production of 30 GHz power for the high-gradient testing of CLIC accelerating structures. To this end a dedicated beam line, power generating structure and power transfer line have been designed, installed and commissioned. 52 MW of 30 GHz power with a pulse length of 74 ns and a repetition rate of 16 Hz were delivered to the high-gradient test area. This will allow operation of test accelerating structures in the first CTF3 run of 2005 up to the nominal CLIC accelerating gradient of 150 MV/m and beyond the nominal pulse length. The system is described and the performances of the CTF3 linac, beam line and the rf components are reviewed. eng 2005

http://cds.cern.ch/record/844031/files/ab-2005-030.pdf;

Imported from Invenio. Hanke, Klaus Sanchez-Conejo, Jorge Scrivens, Richard Dispersion Matching of a Space Charge dominated Beam at Injection into the CERN PS Booster In order to match the dispersion at injection into the CERN PS Booster, the optics of the injection line was simulated using two different codes (MAD and TRACE). The simulations were benchmarked versus experimental results. The model of the line was then used to re-match the dispersion. Experimental results are presented for different optics of the line. Measurements with varying beam current show the independence of the measured quantity of space-charge effects. eng 2005

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=ab-2005-032; https://accelconf.web.cern.ch/p05/PAPERS/TPAT054.PDF; http://cds.cern.ch/record/851579/files/ab-2005-032.pdf;

Imported from Invenio. Robert-Demolaize, Guillaume Assmann, R W Redaelli, Stefano Schmidt, Frank A New Version of Sixtrack with Collimation and Aperture Interface Simulations of collimation and beam cleaning were so far often performed with simplified computer models. However, the increase in available CPU power has opened the possibility for far more realistic simulations. For large accelerators like LHC it is now possible to track millions of particles, element by element over hundreds of turns. The well established SixTrack code treats the full six-dimensional phase space and considers the non-linear magnet components up to very high order. This code is being used for all LHC tracking simulations and has well developed linear and non-linear error models. SixTrack was extended for tracking of large ensembles of halo particles, taking into account halo interaction with arbitrarily placed collimators. An interface to a program for aperture analysis allows obtaining beam loss maps in the machine aperture. A standardized and portable SixTrack version is now available, providing all functionality of the old SixTrack, as well as the newly added support for halo tracking, collimation and aperture loss maps. eng 2005

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=ab-2005-033; https://accelconf.web.cern.ch/p05/PAPERS/FPAT081.PDF; http://cds.cern.ch/record/851591/files/ab-2005-033.pdf;

Imported from Invenio. Wenninger, Jörg Arduini, Gianluigi Arimatea, Claudio Bohl, T Collier, Paul Cornelis, Karel Energy Calibration of the SPS with Proton and Lead Ion Beams The momentum of the 450 GeV/c proton beam of the CERN Super Proton Synchrotron was determined by a high precision measurement of the revolution frequencies of proton and lead ion beams. To minimize systematic errors the magnetic cycle of the SPS had to be rigorously identical for both beams, and corrections due to Earth tides had to be taken into account. This paper presents how the beam momentum was determined from the RF frequency for which the beams are centred in the machine sextupoles. The measured beam momentum is 449.16 +/_ 0.14 GeV/c for a nominal momentum of 450 GeV/c, and the accuracy is limited by systematic errors. eng 2005

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=ab-2005-034; https://accelconf.web.cern.ch/p05/PAPERS/TPAP016.PDF; http://cds.cern.ch/record/851592/files/ab-2005-034.pdf;

Imported from Invenio. Schmidt, Frank Chao Yu Chiu Goddard, B Jacquet, D Kain, V Lamont, M Mertens, V Uythoven, J Wenninger, J MAD-X PTC Integration 1272 MAD-X is CERN's successor for MAD8, a program for accelerator design with a long history. MAD-X is a modular, better maintainable re-write of MAD8 with data structures written in `C'. Early on in the design of MAD-X we relied on the fact that older or doubtful modules could be replaced by new modules using the PTC code by E. Forest. Both codes remain independent entities but are linked via a converter to the MAD-X data structures. PTC is used for symplectic tracking of smaller machines and transfer line using better defined physical models of the elements and taking into account of how the elements are placed in the tunnel. The matching of the LHC will profit form the fact that the high order nonlinear parameters are provided by a PTC Normal Form analysis. eng 2005

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=ab-2005-036; https://accelconf.web.cern.ch/p05/PAPERS/MPPE012.PDF; http://cds.cern.ch/record/858333/files/ab-2005-036.pdf;

Imported from Invenio. Faus-Golfe, Angeles Arduini, Gianluigi Tomas, Rogelio Zimmermann, Frank 2003-2004 Nonlinear Optics Measurements and Modeling for the CERN SPS In 2003 and 2004 nonlinear chromaticity, amplitude detuning, chromatic phase advance, resonance driving terms and off-energy orbits were measured in the CERN SPS at 14 GeV/c and 26 GeV/c, respectively. From the nonlinear chromaticity, the SPS optics model has been updated, by adjusting the strength of nonlinear field errors in dipoles and quadrupoles. Furthermore, we have added to the model the effect of the displacement of all main bends and the voluntary misalignments of all the other elements of the machine. We compare the field errors with those founded in 2002, 2001 and 2000. The tune shifts with transverse amplitude, driving terms, etc., predicted by this nonlinear optics model are compared with direct measurements. eng 2005

http://documents.cern.ch/cgi-bin/setlink?base=generic&categ=public&id=cer-002542502; http://cds.cern.ch/record/859404/files/cer-002542502.pdf;

Imported from Invenio. Cappi, R Gilardoni, S S Giovannozzi, Massimo Martini, M Métral, E Müller, A S Steerenberg, R Final Results from the Novel Multi-turn Extraction Studies at CERN Proton Synchrotron Recently a novel approach to perform multi-turn extraction was proposed based on beam splitting in the transverse phase space by means of trapping inside stable islands. An experimental campaign was launched since the year 2002 to assess the feasibility of such an extraction scheme at the CERN Proton Synchrotron. During the year 2004 run, a high-intensity single-bunch beam was successfully split and the generated beamlets separated without any measurable losses. The latest experimental results are presented and discussed in details in this paper. These achievements represent a substantial step forward with respect to what achieved in previous years, as only a low-intensity bunch could be split without losses. Furthermore, this opens the possibility of using such a technique for routine operation with the high-intensity proton beams required for the planned CERN Neutrino to Gran Sasso Project. eng 2005

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=ab-2005-038; https://accelconf.web.cern.ch/p05/PAPERS/MOPC001.PDF; http://cds.cern.ch/record/859407/files/ab-2005-038.pdf;

Imported from Invenio. Giovannozzi, Massimo Morel, J A Novel Technique for Multi-turn Injection in a Circular Accelerator using Stable Islands in Transverse Phase Space By applying a time-reversal to the multi-turn extraction recently proposed, a novel approach to perform multi-turn injection is described. It is based on the use of stable islands of the horizontal phase space generated by means of sextupoles and octupoles. A particle beam can be injected into stable islands of phase space, and then a slow tune variation allows merging the beam trapped inside the islands. The results of numerical simulations will be presented and discussed in details, showing how to use the proposed approach to generate hollow bunches. eng 2005

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=ab-2005-039; https://accelconf.web.cern.ch/p05/PAPERS/TPAT014.PDF; http://cds.cern.ch/record/859409/files/ab-2005-039.pdf;

Imported from Invenio. Huttel, Erhard Birkel, Ingrid Giovannozzi, Massimo Kalefa, Asem B Pont, Montserrat Wesolowski, Pawel Operation with a Low Emittance Optics at Anka The electron storage ring at ANKA is designed as a variation of an eightfold DBA structure. Since its commissioning the facility has been operated with zero dispersion in the long straight sections resulting in an emittance of about 100 nmrad. Since mid 2004 ANKA is operated with dispersion distributed over the complete ring thus reducing the emittance to 50 nmrad. Optics calculations and measurements as well as operational experience will be discussed. In order to reduce the losses due to Touschek scattering, a lengthening of the bunches was done by modulation of the main frequency with twice the synchroton frequency. An increase of the lifetime by 5 h could be achieved. eng 2005

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=ab-2005-040; https://accelconf.web.cern.ch/p05/PAPERS/RPAE037.PDF; http://cds.cern.ch/record/859410/files/ab-2005-040.pdf;

Imported from Invenio. Métral, E Overview of Impedance and Single-Beam Instability Mechanisms The transverse resistive-wall impedance is discussed in the particular case of the LHC collimators, which reveal a new physical regime. Single-bunch and coupled-bunch instability mechanisms are then reviewed in both longitudinal and tranverse planes. Stabilization by Landau damping, feedbacks, or linear coupling between the transverse planes will also be treated. eng 2005

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=ab-2005-041; http://cds.cern.ch/record/859658/files/ab-2005-041.pdf;

Imported from Invenio. Roncarolo, Federico Dehning, Bernd Transverse Emittance blow-up due to the Operation of Wire Scanners, Analytical Predictions and Measurements Wire Scanner monitors are used in the CERN accelerators to measure the transverse beam size. In the SPS and the LHC they will serve as calibration devices for other emittance monitors. The PSB, PS and SPS are equipped with scanners which move through the beam a 30 um wire through the beam, with a speed that can vary between 0.4 to 20 m/s. During each scan, the beam suffers an emittance blow up, due to multiple Coulomb scattering of the beam protons on the lattice nuclei of the wire material. The effect depends on the particles energy, the betatron function at the monitor location and on the monitor characteristics (wire material, diameter and speed). The comparaison between the predicted emittance increase and a number of experimental measurements is presented. For the small LHC beams the relative emittance blow-up can exceed several 10-2 in the SPS. eng 2005

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=ab-2005-042; https://accelconf.web.cern.ch/p05/PAPERS/TOPC005.PDF; http://cds.cern.ch/record/872259/files/ab-2005-042.pdf;

Imported from Invenio. Schulte, Daniel Different Options for Dispersion Free Steering in the CLIC Main Linac Sophisticated beam-based alignment is essential in future linear colliders to preserve the beam emittance during the transport through the main linac. One such method is dispersion free steering. In this paper different options to implement this method are discussed, based on the use of different accelerating gradients, RF phases and bunch particle types during a beam pulse. eng 2005

https://accelconf.web.cern.ch/p05/PAPERS/RPPP011.PDF; http://cds.cern.ch/record/879699/files/ab-2005-044.pdf;

Imported from Invenio. Braun, Hans Heinrich CLIC progress towards Multi-TeV Linear Colliders. New parameters of an e+/e- Linear Collider based on CLIC technology for a luminosity of 7∙1034 cm-2s-1 at a nominal energy of 3 TeV are presented. They are derived in part from the very successful tests and experience accumulated in the CLIC Test facility, CTF2. A new and ambitious test facility, CTF3, presently under construction at CERN in an international collaboration of laboratories and institutes, and aimed at demonstrating the key feasibility issues of the CLIC scheme, is described. eng 2005

https://accelconf.web.cern.ch/p05/PAPERS/TOPE004.PDF; http://cds.cern.ch/record/879700/files/ab-2005-045.pdf;

Imported from Invenio. Eliasson, Peder Schulte, Daniel Luminosity Tuning Bumps in the CLIC Main Linac Preservation of beam emittance in the CLIC main linac is a challenging task. This requires not only beam-based alignment of the beam line components but also the use of emittance tuning bumps. In this paper the potential use of luminosity tuning bumps is explored and compared to emittance tuning bumps. eng 2005

https://accelconf.web.cern.ch/p05/PAPERS/RPPP009.PDF; http://documents.cern.ch/archive/electronic/other/uploader/EUROTeV/Report/EUROTeV-Report-2005-006.pdf; http://cds.cern.ch/record/879705/files/ab-2005-046.pdf; http://cds.cern.ch/record/879705/files/EUROTeV-Report-2005-006.pdf;

Imported from Invenio. Korostelev, Maxim S Zimmermann, Frank CLIC Damping Ring Optics Design Studies In this paper the nonlinearities induced by the short period NbFeB permanent wiggler optimized for the CLIC damping ring and their influence to the beam dynamics are studied. eng 2005

https://accelconf.web.cern.ch/p05/PAPERS/RPPP007.PDF; http://cds.cern.ch/record/879706/files/ab-2005-047.pdf;

Imported from Invenio. Lifshitz, Ronen D Schulte, Daniel Automatic Steering for the CTF3 Linear Accelerator A system for automatic beam steering has been developed and installed in the CLIC Test Facility - CTF3 linear accelerator at CERN. Using a simple beam position-reading minimisation for trajectory correction, this system has been tested in the 2004 summer run of CTF3. It has already been proven useful as a tool in machine commissioning and operation. In this paper, the CTF3 automatic steering system is introduced, trajectory correction results are presented, and the agreement with a simulation model of the machine is discussed. eng 2005

https://accelconf.web.cern.ch/p05/PAPERS/FPAT002.PDF; http://documents.cern.ch/archive/electronic/other/uploader/CARE/Conf/care-conf-05-036.pdf; http://cds.cern.ch/record/879707/files/ab-2005-048.pdf; http://cds.cern.ch/record/879707/files/care-conf-05-036.pdf;

Imported from Invenio. Zimmermann, Frank Agoh, Tomonori Korostelev, Maxim S Schulte, Daniel Yokoya, Kaoru Collective Effects in the CLIC Damping Rings The small emittance, short bunch length, and high current in the CLIC damping ring could give rise to collective effects which degrade the quality of the extracted beam. In this paper, we survey a number of possible instabilities and estimate their impact on the ring performance. The effects considered include fast beam-ion instability, coherent synchrotron radiation, Touschek scattering, intrabeam scattering, resistive-wall wake fields, and electron cloud. eng 2005

https://accelconf.web.cern.ch/p05/PAPERS/RPPP012.PDF; http://cds.cern.ch/record/879708/files/ab-2005-049.pdf;

Imported from Invenio. Schulte, Daniel Syratchev, Igor V Considerations on the Design of the Decelerator of the CLIC Test Facility (CTF3) One of the main aims of the CLIC Test Facility (CTF3) is to study the beam stability in the drive beam decelerator and to benchmark the performance against beam simulation codes. Particular challenges come from the large drive beam energy spread, the strong wakefields and potential beam losses. The development towards a decelerator design and the required instrumentation is described in this paper. eng 2005

https://accelconf.web.cern.ch/p05/PAPERS/RPPP010.PDF; http://documents.cern.ch/archive/electronic/other/uploader/CARE/Conf/care-conf-05-035.pdf; http://cds.cern.ch/record/879709/files/ab-2005-050.pdf; http://cds.cern.ch/record/879709/files/care-conf-05-035.pdf;

Imported from Invenio. Bordry, Frederick Burnet, Jean Paul Völker, F V CERN-PS Main Power Converter Renovation: How to Provide and Control the Large Flow of Energy for a Rapid Cyclic Machine? The PS accelerator (Proton-Synchrotron) at CERN, which is part of the LHC injector chain, is composed of one hundred magnets connected in series. During a typical acceleration cycle (taking 2.4 seconds), the active power at the magnet terminals varies from plus to minus 40 MW. As this large active power variation was not acceptable to the electrical network, a motor-generator set (M-G) was inserted between the grid and the load. The M-G set (of 1968) acts as a fly-wheel with a stored kinetic energy of 233 MJ and the magnets are fed via two 12-pulse thyristor rectifiers. A renovation or replacement of the installation is planned in the near future as part of the consolidation of the LHC injectors to avoid any major breakdown, to improve overall availability and to reduce operation and maintenance costs. This paper presents a first comparison of technical solutions available to build such a power system and the strategy that will be applied for the up-grade of the system. eng 2005

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=ab-2005-051; https://accelconf.web.cern.ch/p05/PAPERS/WPAE063.PDF; http://cds.cern.ch/record/881714/files/ab-2005-051.pdf;

Imported from Invenio. Andersson, J Jensen, L K Jones, R Steinhagen, Ralph J Wenninger, J LHC Orbit Stabilization Tests at the SPS The LHC, presently being built at CERN, is the first proton collider that requires a continuous orbit control for safe and reliable machine operation. A realistic test of the orbit feedback system was performed in 2004 using already-present LHC instrumentation and infrastructure on a 270GeV coasting beam in the Super-Proton-Synchrotron. It has been demonstrated that the chosen feedback architecture can stabilise the beam better than 10 micrometres and is essentially limited by the noise of the beam position monitor and the bandwidth of the corrector magnets. The achieved orbit stability is comparable to those found at modern light sources and gives enough operational margin with respect to the requirements of the LHC Cleaning System (70mm). Estimates for the longterm drifts and achievable stability will be presented based on the experimental results. eng 2005

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=ab-2005-052; https://accelconf.web.cern.ch/p05/PAPERS/MPPP004.PDF; http://cds.cern.ch/record/881957/files/ab-2005-052.pdf;

Imported from Invenio.