Tuckmantel, J.

Paper	Title	Page
TUPC103	Digital Generation of Noise-signals with Arbitrary Constant or Time-varying Spectra	1299
	J. Tuckmantel CERN, Geneva
	Noise sources in the RF system of an accelerator produce longitudinal emittance increase or loss. This noise is inherent, from the beam-control system electronics, external sources or high power components, or can be purposely injected for a specific need such as bunch distribution modification or controlled emittance increase. Simulations to study these effects on the beam require precise reproduction either of the total noise measured on the hardware, or of the noise spectrum to be injected and optimized to produce the desired changes. In the latter case the 'optimized' noise source has also to be created in real-time to actually excite the beam via the RF system. This paper describes a new algorithm to create noise spectra of arbitrary spectral density varying with cycle time. It has very good statistical properties and effectively infinite period length, important for long simulation runs. It is spectrally clean and avoids undesired mirror spectra. Coded in C++, it is flexible and fast. Used extensively in simulations it has also successfully created controlled emittance increase in the SPS by the injection of artificial real-time RF noise.
TUPP059	Study of Controlled Longitudinal Emittance Blow-up for High Intensity LHC Beams in the CERN SPS	1676
	G. Papotti, T. Bohl, T. P.R. Linnecar, E. N. Shaposhnikova, J. Tuckmantel CERN, Geneva
	Preventive longitudinal emittance blow-up, in addition to a fourth harmonic Landau damping RF system, is required to keep the LHC beam in the SPS stable up to extraction. The beam is blown-up in a controlled way during the acceleration ramp by using band-limited phase noise targeted to act inside the synchrotron frequency spread, which is itself modified both by the second RF system and by intensity effects (beam loading and others). For a high intensity beam these latter effects can lead to a non-uniform emittance blow-up and even loss of stability for certain bunches in the batch. In this paper we present studies of the emittance blow-up achieved with high intensity beams under different conditions of both RF and noise parameters.
TUPP066	CERN SPS Impedance in 2007	1691
	E. Métral, G. Arduini, T. Bohl, H. Burkhardt, F. Caspers, H. Damerau, T. Kroyer, H. Medina, G. Rumolo, M. Schokker, E. N. Shaposhnikova, J. Tuckmantel CERN, Geneva R. Calaga BNL, Upton, Long Island, New York B. Salvant EPFL, Lausanne B. Spataro INFN/LNF, Frascati (Roma)
	Each year several measurements of the beam coupling impedance are performed in both longitudinal and transverse planes of the CERN Super Proton Synchrotron to keep track of its evolution. In parallel, after the extensive and successful campaign of identification, classification and cure of the possible sources of (mainly longitudinal) impedance between 1998 and 2001, a new campaign (essentially for the transverse impedance this time) has started few years ago, in view of the operation of the SPS with higher intensity for the LHC luminosity upgrade. The present paper summarizes the results obtained from the measurements performed over the last few years and compares them to our predictions. In particular, it reveals that the longitudinal impedance is reasonably well understood and the main contributors have already been identified. However, the situation is quite different in the transverse plane: albeit the relative evolution of the transverse impedance over the last few years can be well explained by the introduction of the nine MKE kickers necessary for beam extraction towards the LHC, significant contributors to the SPS transverse impedance have not been identified yet.
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.
THPC125	Modeling and Simulation of the Longitudinal Beam Dynamics-RF Station Interaction in the LHC Rings	3278
	T. Mastorides, J. D. Fox, C. H. Rivetta, D. Van Winkle SLAC, Menlo Park, California P. Baudrenghien, J. Tuckmantel CERN, Geneva
	A non-linear time-domain simulation has been developed to study the interaction between longitudinal beam dynamics and RF stations in the LHC rings. The motivation for this tool is to study the effect of RF station noise, impedance, and perturbations on the beam life and longitudinal emittance. It will be also used to determine optimal LLRF configurations, to study system sensitivity on various parameters, and to define the operational and technology limits. It allows the study of alternative LLRF implementations and control algorithms. The insight and experience gained from our PEP-II simulation is important for this work. In this paper we discuss properties of the simulation tool that will be helpful in analyzing the LHC RF system and its initial results. Partial verification of the model with data taken during the LHC RF station commissioning is presented.