betatron

Paper	Title	Other Keywords	Page
DYN03	Studies of the Electron-Cloud-Induced Beam Dynamics at CesrTA	electron, emittance, single-bunch, synchrotron	60
	G. Dugan, M. Billing, R. Meller, M. Palmer, G. Ramirez, J. Sikora, K. Sonnad, H. Williams Cornell University - CLASSE R. Holtzapple California Polytechnic State University
	This talk will review recent data and simulation results related to electron-cloud induced beam dynamics studies at Cesr-TA.
	Slides
PST07	Techniques for Observing Beam Dynamical Effects Caused by the Presence of Electron Clouds	electron, kicker, feedback, dipole	108
	M. Billing, G. Dugan, R. Meller, M. Palmer, G. Ramirez, H. Williams, J. Sikora Cornell University - CLASSE R. Holtzapple California Polytechnic State University
	During the last several years CESR has been studying the effects of electron clouds on stored beams in order to understand their impact on future linear-collider damping ring designs. One of the important issues is the way that the electron cloud alters the dynamics of bunches within the train. Techniques for observing the dynamical effects of beams interacting with the electron clouds have been developed. These methods and examples of measurements are presented here.
PST11	CesrTA Low Emittance Tuning	quadrupole, coupling, sextupole, emittance	134
	D. Sagan, J. Shanks, Y. Yanay, D. Rubin Cornell University - CLASSE
	Low emittance tuning and characterization of electron cloud phenomena are central to the CesrTA R&D program. A small vertical emittance is required in order to be sensitive to the emittance diluting effects of the electron cloud. We have developed techniques to systematically and efficiently eliminate optical and alignment errors that are the sources of vertical emittance. Beam based measurements are used to center the beam position monitors with respect to the adjacent quadrupoles, determine the relative gains of the BPM button electrodes, and measure the BPM tilts, thus allowing precision measurement of transverse coupling and vertical dispersion. Low emittance also requires that the tune plane be relatively clear of nonlinear coupling resonances associated with sextupoles. We report on tests of a sextupole distribution designed to minimize resonance driving terms. We also report on efforts to measure sextupole strengths. Our standard low emittance tuning procedure typically yields sub 20pm emittance in one or two iterations. With tuning, we achieve a vertical emittance of ?v ~15 pm at 2.1 GeV.
FTR02	Simulation of Electron Cloud Induced Instabilities and Emittance Growth for CesrTA	emittance, simulation, electron, synchrotron	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