Pivi, M.

Paper	Title	Page
MIT01	Electron Cloud Mitigation Investigations at CesrTA	41
	J. Calvey, J. Makita, M. Palmer, R. Schwartz, C. Strohman Cornell University - CLASSE S. Calatroni, G. Rumolo CERN K. Kanazawa, Y. Suetsugu KEK M. Pivi, L. Wang SLAC National Accelerator Laboratory
	Over the course of the CesrTA program at Cornell, over 30 Retarding Field Analyzers (RFAs) have been installed in the CESR storage ring. These devices, which measure the local electron cloud density and energy distribution, have been deployed in drift, dipole, quadrupole, and wiggler field regions. They can be used to evaluate the efficacy of cloud mitigation techniques in each magnetic field element. Techniques investigated so far include different beam pipe coatings, grooves, and clearing electrodes. This talk will provide an overview of the electron cloud mitigation program at CESR, give a preliminary evaluation of the effectiveness of various mitigation techniques, and discuss methods used to obtain quantitative information about vacuum chamber properties via simulation.
	Slides
DYN00	Feedback Control of SPS E-clouds / Transverse Mode Coupled Instabilities	50
	C. Rivetta, A. Bullitt, J. Fox, T. Mastorides, G. Ndabashimiye, M. Pivi, O. Turgut SLAC National Accelerator Laboratory R. Secondo, J. Vay LBNL W. Hofle, B. Salvant CERN
	Electron cloud driven instability can impose limitations on the maximum stored beam current in present and future accelerators. It drives inter-bunch and intra-bunch instabilities. Feedback control techniques have been proposed to mitigate transverse instabilities within a bunch as an extension of techniques used to control inter-bunch (coupled-bunch) instabilities. The US LHC Accelerator Research Program (LARP) has supported a collaboration between US labs and CERN to explore systems to mitigate E-cloud instabilities and transverse mode coupled instability (TMCI ) for the SPS and LHC machines. For intra-bunch (within a bunch) control of nanosecond scale bunch lengths the feedback channel has to be wide-band (GHz range) to be able to measure and control the vertical position of individual sections of a bunch. The design and implementation of the feedback control system involves the modeling and identification of the bunch dynamics, the design of a feedback control algorithm, and the selection of digital and analog hardware that operates in the GHz range. We present the goals of this collaboration and analyze the different research lines to implement and evaluate a full-function prototype feedback system for the SPS. We include details of the feedback system topology and technical limitations, modeling and identification of the bunch dynamics via simulators and machine measurements. We estimate the necessary control bandwidths, and complexity of the processing channel via design considerations for the control algorithm. Very initial efforts at modeling feedback control via reduced bunch models and semi-realistic feedback system specifications are presented.
	Slides
PST05	Progress on Simulation of Beam Dynamics with Electron Cloud Effects: An update	100
	K. Sonnad Cornell University - CLASSE M. Pivi SLAC National Accelerator Laboratory J. Vay LBNL G. Rumolo, R. Tomas, F. Zimmermann CERN G. Franchetti GSI
	In this presentation, we will report the progress made in the past few years on simulations to study the electron cloud effects on the dynamics of beams in cicular accelerators. Results associated with various acclerators such as the Fermilab Main Injector, SPS, LHC, ILC damping rings will be shown. Comparisions between the results obtained from three codes, namely Warp, HeadTail and CMad will be discussed. More recent studies done on CesrTA will be discussed in greater detail.
MOD05	Trapping of Electron Cloud in ILC / CesrTA Quadrupole and Sextupole Magnets	167
	M. Pivi, L. Wang SLAC National Accelerator Laboratory
	This talk will discuss the electron trapping mechanism in quadrupole and sextupole magnets. We will present the results in CESRTA and ILC quadrupole and sextupole magnets.
	Slides
FTR02	Simulation of Electron Cloud Induced Instabilities and Emittance Growth for CesrTA	203
	M. Pivi SLAC National Accelerator Laboratory G. Dugan, M. Palmer, K. Sonnad Cornell University - CLASSE
	As part of the international Linear Collider (ILC) collaboration, we have compared the electron cloud (EC) effect for different Damping Ring (DR) designs respectively with 6.4 km and 3.2 km circumference and investigated the feasibility of the shorter damping ring with respect to the electron cloud build-up and related beam instabilities. The studies for a 3.2 km ring were carried out with beam parameters of the ILC Low Power option. A reduced damping ring circumference has been proposed for the new ILC baseline design and would allow considerable reduction of the number of components, wiggler magnets and costs. We also present the results for the luminosity upgrade option with shorter 3ns bunch spacing. In particular we will go through the evaluation of mitigation techniques for the ILC DR and discuss the integration of the CesrTA results into the Damping Ring design. Furthermore (with Kiran Sonnad, Cornell) we have performed detailed simulations using the CMAD code for CesrTA single-bunch instability and linear emittance growth below threshold and preliminary comparisons with experimental data are discussed here in view of the validation of the simulation codes prediction for the ILC DR.
	Slides