Schulte, D.

Paper	Title	Page
MOPP001	Beam-Based Alignment for the CLIC Decelerator	547
	E. Adli, D. Schulte CERN, Geneva
	The CLIC Drive Beam decelerator requires the beam to be transported with very small losses. Beam-based alignment is necessary in order to achieve this, and various beam-based alignment schemes have been tested for the decelerator lattice. The decelerator beam has an energy spread of up to 90%, which impacts the performance of the alignment schemes. We have shown that Dispersion-Free-Steering works well for the decelerator lattice. However, because of the transverse focusing approach, modifications of the normal DFS schemes must be applied. Tune-up scenarios for the CLIC decelerator using beam-based alignment are also discussed.
MOPP002	A Study of Failure Modes in the CLIC Decelerator	550
	E. Adli, D. Schulte, I. Syratchev CERN, Geneva
	The CLIC Drive Beam decelerator is responsible for producing the RF power for the main linacs, using Power Extraction and Transfer Structures (PETS). To provide uniform power production, the beam must be transported with very small losses. In the paper failure modes for the operation of the decelerator are investigated, and the impact on beam stability, loss level and machine protection issues is presented. Quadrupole failure, PETS inhibition and PETS break down scenarios are being considered.
MOPP011	Fast Vertical Beam Instability in the CTF3 Combiner Ring	574
	R. Corsini, D. Schulte, P. K. Skowronski, F. Tecker CERN, Geneva D. Alesini, C. Biscari, A. Ghigo INFN/LNF, Frascati (Roma)
	The CLIC Test Facility CTF3 is being built at CERN by an international collaboration, in order to demonstrate the main feasibility issues of the CLIC two-beam technology by 2010. The facility includes an 84 m combiner ring, which was installed and put into operation in 2007. High-current operation has shown a vertical beam break-up instability, leading to high beam losses over the four turns required for nominal operation of the CTF3 ring. Such instability is most likely due to the vertically polarized transverse mode in the RF deflectors used for beam injection and combination. In this paper we report the experimental data and compare them with simulations. Possible methods to eliminate the instability are also outlined.
MOPP027	Placet Based Start-to-end Simulations of the ILC with Intra-train Fast Feedback System	604
	J. Resta-López, P. Burrows, A. F. Hartin JAI, Oxford A. Latina, D. Schulte CERN, Geneva
	Integrated simulations are important to assess the reliability of the luminosity performance of the future linear colliders. In this paper we present multi-bunch tracking simulation results for the International Linear Collider (ILC) from the start of the LINAC to the interaction point. The tracking along the LINAC and the beam delivery system is done using the code Placet. This code allows us to introduce cavity wakefield effects, element misalignment errors and ground motion. Static beam based alignment of the LINAC are also considered. The luminosity and beam-beam parameters are calculated using the code Guinea-Pig. In the framework of the Feedback On Nano-second Timescales (FONT) project, we describe and simulate an updated fast intra-train feedback system in order to correct for luminosity degradation mainly due to high frequency ground motion.
MOPP028	Technical Specification for the CLIC Two-Beam Module	607
	G. Riddone, H. Mainaud Durand, D. Schulte, I. Syratchev, W. Wuensch, R. Zennaro CERN, Geneva R. Nousiainen HIP, University of Helsinki A. Samoshkin JINR, Dubna, Moscow Region
	The 2-m long CLIC module comprises four decelerating structures and two quadrupoles forming a FODO cell. Each decelerating structure powers two accelerating structures. Some accelerating structures are removed at regular intervals to liberate space for a quadrupole of a FODO lattice. The present layout of the standard and special modules is presented as well as the status of the system integration. The main requirements for the different sub-systems (alignment, supporting, stabilization, cooling and vacuum) are introduced together with the major integration constraints. For the key components the specification on pre-alignment and beam-based alignment tolerances is also recalled as well as their influence on the requirements of other sub-systems. For example the required stable thermal behavior and the tight tolerances of accelerating structure (the requirements for the accelerating structure pre-alignment is 0.014 mm at 1? ) in the CLIC linac largely directly the sizing and integration of the cooling system. The paper also covers the main issues related to the module integration in the tunnel. In the last part, the critical issues and future activities are summarized.
MOPP037	Alignment of the CLIC BDS	628
	A. Latina, D. Schulte, R. Tomas CERN, Geneva
	Aligning the CLIC Beam Delivery System faces two major challenges, the tight tolerances for the emittance preservation and its strong non-linear beam dynamics. For these reasons conventional beam-based alignment techniques, like dispersion free steering, are only partially successful and need to be followed by optimization algorithms based on other observables, like beam sizes.
MOPP038	Optimizing the CLIC Beam Delivery System	631
	R. Tomas BNL, Upton, Long Island, New York H.-H. Braun, M. Jorgensen, D. Schulte CERN, Geneva
	The optimization of the new CLIC Final Focus System (FFS) with L*=3.5m is presented for a collection of CLIC beam parameters. The final performance is computed for the full Beam Delivery System including the new diagnostics section. A comparison to previous designs is also presented.
MOPP048	Fast Ion Instability in the CLIC Transfer Line and Main Linac	655
	G. Rumolo, D. Schulte CERN, Geneva
	The Fast Ion Instability is believed to be a serious danger for bunch trains propagating in the CLIC electron transfer line and main linac, since it may strongly affect the bunches in the tail of the train if the vacuum pressure is not below a certain threshold. We have developed the FASTION code, which can track electrons through a FODO cell line and takes into account their interactions with the produced (and possibly trapped) ions. We describe how this tool can be used for setting tolerances on the vacuum pressure and for giving specifications for the design of a feedback system.
TUPC005	Simulation Study of Laser-wires as a Post-linac Diagnostic for CLIC and ILC	1047
	G. A. Blair, L. Deacon, S. Malton Royal Holloway, University of London, Surrey I. V. Agapov, A. Latina, D. Schulte CERN, Geneva
	Realistic CLIC and ILC bunch trains are simulated in the linac, including intra-train collective effects, and then analysed via a realistic simulation of a laser-wire system, including effects of laser-wire signal extraction, detection and deconvolution. Implications are drawn for the use of laser-wires as a post-linac machine diagnostic.
TUPP016	A Flight Simulator for ATF2 - A Mechanism for International Collaboration in the Writing and Deployment of Online Beam Dynamics Algorithms	1562
	G. R. White, S. Molloy, A. Seryi SLAC, Menlo Park, California P. Bambade, Y. Renier LAL, Orsay S. Kuroda KEK, Ibaraki D. Schulte, R. Tomas CERN, Geneva
	The goals of ATF2 are to test a novel compact final focus optics design with local chromaticity correction intended for use in future linear colliders. The newly designed extraction line and final focus system will be used to produce a 37nm vertical waist from an extracted beam from the ATF ring of ~30nm vertical normalised emittance, and to stabilise it at the IP-waist to the ~2nm level. Static and dynamic tolerances on all accelerator components are very tight; the achievement of the ATF2 goals is reliant on the application of multiple high-level beam dynamics algorithms to align and tune the electron beam in the extraction line and final focus system. Much algorithmic development work has been done in Japan and by colleagues in collaborating nations in North America and Europe. We describe here development work towards realising a 'flight simulator' environment for the shared development and implementation of beam dynamics code. This software exists as a 'middle-layer' between the lower-level control systems (EPICS and V-SYSTEM) and the multiple higher-level beam dynamics modeling tools in use by the three regions (SAD, Lucretia and PLACET).
TUPP094	Recent Improvements in the Tracking Code PLACET	1750
	A. Latina, H. Burkhardt, G. Rumolo, D. Schulte, R. Tomas CERN, Geneva E. Adli University of Oslo, Oslo Y. Renier LAL, Orsay
	The Tracking Code PLACET has recently undergone several improvements. A redesign of its internal data structures and a new user interface based on the mathematical toolbox Octave have considerably expanded its simulation capabilities. Several new lattice elements, optimization algorithms and physics processes have been added to allow for more complete start-to-end simulations. The usage of the AML language and the Universal Parser Library extened its interfacing capability.
WEPP158	Simulation of beam Halo in CLIC Collimation Systems	2859
	G. A. Blair, S. Malton Royal Holloway, University of London, Surrey I. V. Agapov, A. Latina, D. Schulte CERN, Geneva
	Full simulation of the CLIC and ILC collimation systems are performed to take account of collimator wakefield effects from the core beam on the halo. In addition full simulation of the interaction of the halo with the collimator material is performed to study the effect of multiple scattering and also the production of neutrons in the electromagnetic showers. The effect of beam-gas scattering downstream of the collimators is also included.
THPC018	Beam Dynamics Issues in the CLIC Long Transfer Line	3017
	J. B. Jeanneret, E. Adli, A. Latina, G. Rumolo, D. Schulte, R. Tomas CERN, Geneva
	Both the main beam and the drive beam of the CLIC project must be transported from the central production site to the head of the main linacs over more than twenty kilometres. Over such distances chromatic aberrations are substantial. With long distances and large beam currents, detuning and instabilities associated to ion production and multi-bunch resistive wall effects must also be considered. These effects are quantified and simulated. Based on these results, we propose a baseline design for these two lines.
WEOAG01	Prospects for a Large Hadron Electron Collider (LHeC) at the LHC	1903
	M. Klein Liverpool University, Science Faculty, Liverpool H. Aksakal N. U, Nigde F. Bordry, H.-H. Braun, O. S. Brüning, H. Burkhardt, R. Garoby, J. M. Jowett, T. P.R. Linnecar, K. H. Mess, J. A. Osborne, L. Rinolfi, D. Schulte, R. Tomas, J. Tuckmantel, F. Zimmermann, A. de Roeck CERN, Geneva S. Chattopadhyay, J. B. Dainton Cockcroft Institute, Warrington, Cheshire A. K. Ciftci Ankara University, Faculty of Sciences, Tandogan/Ankara A. Eide EPFL, Lausanne B. J. Holzer DESY, Hamburg P. Newman Birmingham University, Birmingham E. Perez CEA, Gif-sur-Yvette S. Sultansoy TOBB ETU, Ankara A. Vivoli LAL, Orsay F. J. Willeke BNL, Upton, New York
	The LHeC collides a lepton beam with one of the intense, LHC, hadron beams. It achieves both e± interactions with quarks at the terascale, at eq masses in excess of 1 TeV, with a luminosity of about 1033 cm-2 s-1, and it also enables a sub-femtoscopic probe of hadronic matter at unprecedented chromodynamic energy density, at Bjorken-x values down to 10-6 in the deep inelastic scattering domain. The LHeC combines the LHC infrastructure with recent advances in radio-frequency, in linear acceleration and in other associated technologies, to enable two proposals for TeV ep collisions: a "ring-ring" option in which 7 TeV protons (and ions) collide with about 70 GeV electrons/positrons in a storage ring in the LHC tunnel and a "linac-ring" option based on an independent superconducting linear accelerator enabling single-pass collisions of electrons and positrons of up to about 140 GeV with an LHC hadron beam. Both options will be presented and compared. Steps are outlined for completing a Conceptual Design Review of the accelerator complex, beam delivery, luminosity, physics and implications for experiment, following declared support by ECFA and by CERN for a CDR.
	Slides
WEPP154	Linac-LHC ep Collider Options	2847
	F. Zimmermann, F. Bordry, H.-H. Braun, O. S. Brüning, H. Burkhardt, R. Garoby, T. P.R. Linnecar, K. H. Mess, J. A. Osborne, L. Rinolfi, D. Schulte, R. Tomas, J. Tuckmantel, A. de Roeck CERN, Geneva H. Aksakal N. U, Nigde S. Chattopadhyay Cockcroft Institute, Warrington, Cheshire A. K. Ciftci Ankara University, Faculty of Sciences, Tandogan/Ankara J. B. Dainton Liverpool University, Science Faculty, Liverpool A. Eide EPFL, Lausanne B. J. Holzer DESY, Hamburg M. Klein University of Liverpool, Liverpool S. Sultansoy TOBB ETU, Ankara A. Vivoli LAL, Orsay F. J. Willeke BNL, Upton, New York
	We describe various parameter scenarios for a ring-linac ep collider based on LHC and an independent s.c. electron linac. Luminosities of order 1032/cm2/s can be achieved with a standard ILC-like linac, operated either in pulsed or cw mode, with acceptable beam power. Reaching much higher luminosities, up to 1034/cm2/s and beyond, would require the use of two linacs and the implementation of energy recovery. Advantages and challenges of a ring-linac ep collider vis-a-vis an alternative ring-ring collider are discussed.