Arduini, G.

Paper	Title	Page
MOPLT035	Beam Induced Heating of the SPS Fast Pulsed Magnets	623
	J.A. Uythoven, G. Arduini, T. Bohl, F. Caspers, E.H.R. Gaxiola, T. Kroyer, M. Timmins, L. Vos CERN, Geneva
	Fast pulsed magnets with ferrite yokes are used in CERN?s SPS accelerator for beam injection, extraction and excitation for tune measurements. The impedance of the ferrite structures can provoke significant beam induced heating, especially for beams with high peak currents as for LHC operation, even beyond the Curie temperature. The expected heating in the different kicker systems for various operational modes is compared with beam measurements. Estimates of the beam induced power have been derived from measured beam spectra. A fast extraction kicker system has recently been equipped with a cooling system. The measured cooling performance is compared with data from laboratory setups and numerical simulations.
TUZBCH01	Beam Quality Preservation in the CERN PS-SPS Complex	78
	G. Arduini CERN, Geneva
	The LHC will require beams of unprecedented transverse and longitudinal brightness. Their production imposes tight constraints on the emittance growth in each element of the LHC injector chain, namely the PS-SPS Accelerator Complex. The problems encountered at the different stages of the acceleration in the complex span a wide range of topics, such as injection matching, RF gymnastics, space charge, transverse and longitudinal single- and coupled-bunch instabilities, and electron cloud effects. The measurement techniques developed and applied to identify and study the various sources of emittance dilution to the high precision required for the LHC beams and the solutions found to control such phenomena are illustrated.
	Video of talk
	Transparencies
WEPLT044	Electron-cloud Build-up Simulations and Experiments at CERN	1930
	F. Zimmermann, G. Arduini, V. Baglin, T. Bohl, B.J. Jenninger, J.M. Jimenez, J.-M. Laurent, F. Ruggiero, D. Schulte CERN, Geneva
	We compare the predications of electron-cloud build-up simulations with measurements at the CERN SPS. Specifically, we compare the electron flux at the wall, electron-energy spectra, heat loads, and the spatial distribution of the electrons for two different bunch spacings, with variable magnetic fields, and for several chamber temperatures and associated surface conditions. The simulations employ a modified, improved version of the ECLOUD code. The main changes are briefly described. We finally present updated simulation results for the heat load in the cold LHC arcs.
WEPLT046	Localizing Impedance Sources from Betatron-phase Beating in the CERN SPS	1936
	F. Zimmermann, G. Arduini, C. Carli CERN, Geneva
	Multi-turn beam-position data recorded after beam excitation can be used to extract the betatron-phase advance between adjacent beam position monitors (BPMs) by a harmonic analysis. Performing this treatment for different beam intensities yields the change in phase advance with current. A local impedance contributes to the average tune shift with current, but, more importantly, it also causes a mismatch and phase beating. We describe an attempt to determine the localized impedance around the SPS ring by fitting the measured betatron phase shift with current at all BPMs to the expected impedance response matrix.
THPLT015	Accuracy of Profile Monitors and LHC Emittance Measurements	2493
	F. Roncarolo, G. Arduini, B. Dehning, G. Ferioli, J. Koopman, D. Kramer CERN, Geneva
	The monitoring and controlling of the beam transverse emittance is essential to allow high luminosity performances in a collider operation. The profile monitors in the LHC injection chain are exploited to determine their precision. A fit strategy was developed to reduce the fitting procedure error and make it negligible compared to instrumentation errors. The method proved to be robust against non-Gaussian tails and can estimate the fraction of non-Gaussian distributed beam intensity. The procedure was applied to the 2003 SPS Wire Scanner measurements with different kind of LHC type beams. The reproducibility of the six available monitors was determined by choosing one as a reference and making synchronized measurements. Several instrumental errors were discovered and corrected to the one per cent level. The demanding small LHC transverse emittances were determined under different beam conditions in terms of intensity, bunch spacing and length in the PS Booster, PS and SPS.