EPAC 2004 - List of Authors

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Rumolo, G.

Paper	Title	Page
WEPLT008	Simulated Emittance Growth due to Electron Cloud for SPS and LHC	1831
	E. Benedetto, D. Schulte, F. Zimmermann CERN, Geneva G. Rumolo GSI, Darmstadt
	The emittance growth caused by an electron cloud is simulated by the HEADTAIL code. The simulation result depends on the number of beam-cloud "interaction points"(IPs), the phase advance between the IPs, the number of macro-particles used to represent beam and cloud, and on the betatron tune. Simulations include a transverse feedback system and, optionally, a large chromaticity, as employed in actual SPS operation. Simulation results for the SPS are compared with observations, and the emittance growth in the LHC is computed as a function of the average electron density.
WEPLT013	Investigation of Space Charge Effects and Intrabeam Scattering for Lead Ions in the SPS	1843
	H. Burkhardt, D. Manglunki, M. Martini, F. Roncarolo CERN, Geneva G. Rumolo GSI, Darmstadt
	Space charge effects and intrabeam scattering usually play a minor role in high energy machines like the SPS. They can potentially become a limitation for the heavy ion beams needed for the LHC at the injection plateau in the SPS. Experimental studies on space charge limitations performed on low energy proton beams in the SPS will be described. Theoretical studies have been performed to predict emittance growth times due to intrabeam scattering using several different codes.
WEPLT052	A Method to Measure the Skew Quadrupole Strengths in the SIS-18 using Two BPMs	1954
	F. Franchi, T. Beier, M. Kirk, M. Moritz, G. Rumolo GSI, Darmstadt R. Tomas BNL, Upton, Long Island, New York
	In the SIS-18 of GSI a new set of skew quadrupoles has been installed to improve the multi-turn-injection. A new method based on the measurement of the resonance driving terms has been proposed to cross-check the nominal values and polarities of their gradients. Once a beam is transversely kicked, it experiences oscillations whose spectrum contains both the betatron tune line and secondary lines. The amplitude of each line is proportional to the strength of the multipoles, such as skew quadrupoles and sextupoles, present in the lattice. In this paper a recursive algorithm to derive the magnet strength from the spectral lines and the application of this method to the eight skew quadrupoles in the SIS-18 are presented.
WEPLT054	Electron Cloud Build up in Coasting Beams	1960
	G. Rumolo GSI, Darmstadt G. Bellodi CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon K. Ohmi KEK, Ibaraki F. Zimmermann CERN, Geneva
	Electrons could in principle accumulate in the potential of coasting beams of positively charged particles until a balance between the beam force and space charge force from the electrons is reached. But the continuous interaction between a non-ideal perturbed coasting beam and the cloud of electrons being trapped by it, together with the reflection and secondary emission processes at the inner pipe wall, can alter this picture and cause a combined cloud or beam transverse instability long before the concentration of electrons reaches the theoretical equilibrium value. The issue is addressed in this paper by means of combined build-up and instability simulations carried out with the HEADTAIL code.
WEPLT109	Simulation of Ep Instability for a Coasting Proton Beam in Circular Accelerators	2104
	K. Ohmi, T. Toyama KEK, Ibaraki G. Rumolo GSI, Darmstadt
	ep instability is discussed for a coasting beam operation of J-PARC 50 GeV Main Ring. Our previous study (PAC2003) was focussed only ionization electron. We now take into account electrons created at the chamber wall due to proton loss and secondary emission with higher yield than ionization.
WEPLT177	Analysis of Electron Cloud at RHIC	2236
	U. Iriso, M. Blaskiewicz, P. Cameron, K.A. Drees, W. Fischer, H.-C. Hseuh, R. Lee, S. Peggs, L. Smart, D. Trbojevic, S.Y. Zhang BNL, Upton, Long Island, New York G. Rumolo GSI, Darmstadt
	Pressure rises with high intense beams are becoming the main luminosity limitation at RHIC. Observations during the latest runs show beam induced electron multipacting as one of the causes for these pressure rises. Experimental studies are carried out at RHIC using devoted instrumentation to understand the mechanism leading to electron clouds. Possible cures using NEG coated beam pipes and solenoids are experimentally tested. In the following, we report the experimental electron cloud data and analyzed the results using computer simulation codes.
WEPLT181	Measurement of Multipole Strengths from RHIC BPM Data	2239
	R. Tomas, M. Bai, W. Fischer BNL, Upton, Long Island, New York F. Franchi, G. Rumolo GSI, Darmstadt
	Recently resonance driving terms were successfully measured in the CERN SPS and the BNL RHIC from the Fourier spectrum of BPM data. Based on these measurements a new analysis has been derived to extract multipole strengths.In this paper we present experimental measurements of sextupolar and skew quadrupolar strengths carried out at RHIC. Also discussed is the possibility of a non-destructive measurement using an AC dipole.
THPLT017	Review and Comparison of Simulation Codes Modeling Electron-Cloud Build Up and Instabilities	2499
	F. Zimmermann, E. Benedetto, F. Ruggiero, D. Schulte CERN, Geneva G. Bellodi CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon M. Blaskiewicz, L. Wang BNL, Upton, Long Island, New York Y. Cai, M.T.F. Pivi SLAC, Menlo Park, California V.K. Decyk, W. Mori UCLA, Los Angeles, California M.A. Furman LBNL/AFR, Berkeley, California A.F. Ghalam, T. Katsouleas USC, Los Angeles, California K. Ohmi, S.S. Win KEK, Ibaraki G. Rumolo GSI, Darmstadt
	Several computer codes written at various laboratories are employed for modelling the generation and the consequences of an electron cloud. We review the most popular of these programs, which simulate either the build of an electron cloud or the instabilities it produces, and we compare simulation results for identical, or similar, input parameters obtained from the various codes.