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TY - UNPB AU - Lebedev, V.A. AU - Antipov, S. A. ED - Schaa, Volker RW TI - New Electron Cloud Instability Mechanism and its Detection and Suppression J2 - Proc. of HB2018, Daejeon, Korea, 17-22 June 2018 C1 - Daejeon, Korea T2 - ICFA Advanced Beam Dynamics Workshop T3 - 61 LA - english AB - Fast transverse instability was observed in Recycler proton storage ring (RR). The instability develops within 100 turns and may lead to beam loss. The fast rise suggested that the instability is driven by electron cloud. That was later supported by microwave transmission measurements. In difference to RR the instability was not observed in similar conditions in Main Injector (MI). RR is based on combined function dipoles while MI uses pure dipoles. This difference plays a key role in instability development. The instability dynamics was studied experimentally and with numerical simulations. An analytical model predicts that electrons are trapped in RR dipoles. Numerical simulations show that up to 1% of particles can be trapped. The cloud build-up is exponential with its density limited by space charge. That results in the cloud intensity orders of magnitude greater than in MI. A growth rate of about 30 turns and mode frequency of 0.4 MHz are consistent for observations and PEI simulations. The high intensity batch can be stabilized by low intensity clearing bunch injected behind batch which destroys the trapped electron cloud and prevents its multi-turn accumulation. PB - JACoW Publishing CP - Geneva, Switzerland ER -