A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z  

Celata, C. M.

Paper Title Page
MOPP063 A New Chicane Experiment in PEP-II to Test Mitigations of the Electron Cloud Effect for Linear Colliders 688
 
  • M. T.F. Pivi, D. Arnett, F. D. Cooper, D. Kharakh, F. King, R. E. Kirby, B. Kuekan, J. J. Lipari, M. Munro, J. S.T. Ng, J. Olszewski, T. O. Raubenheimer, J. Seeman, B. Smith, C. M. Spencer, L. Wang, W. Wittmer
    SLAC, Menlo Park, California
  • C. M. Celata, M. A. Furman
    LBNL, Berkeley, California
 
  Beam instability caused by the electron cloud has been observed in positron and proton storage rings and it is expected to be a limiting factor in the performance of the positron Damping Ring (DR) of future Linear Colliders such as ILC and CLIC. Possible remedies for the electron cloud effect include thin-film coatings, surface conditioning, antechamber, clearing electrodes, and chamber with grooves or slots. The effect is expected to be particularly severe in magnetic field regions. To test this and possible mitigation methods, we have installed a new 4-dipole chicane experiment in the PEP-II Low Energy Ring (LER). We have also installed test chambers in straight field free regions. The associated chamber consists of bare aluminum and TiN-coated inner surface sections. Each section is instrumented with arrays of readout electrodes and retarding grids. Installation of a grooved chamber is also planned. In this paper, we describe the ongoing R&D effort at SLAC to reduce the electron cloud effect in linear colliders. We present the design of the chicane, the chambers and diagnostics, as well as the experimental results obtained.  
TUPP024 Electron Cyclotron Resonances in Electron Cloud Dynamics 1583
 
  • C. M. Celata, M. A. Furman, J.-L. Vay, J. W. Yu
    LBNL, Berkeley, California
 
  We report a previously unknown resonance for electron cloud dynamics. The 2D simulation code “POSINST” was used to study the electron cloud buildup at different z positions in the International Linear Collider positron damping ring wiggler. At magnetic field values, B, for which the bunch frequency is an integral multiple of the electron cyclotron frequency an enhancement of up to a factor of 3 in the electron cloud equilibrium density was found. At low magnetic fields the effects of the resonance are prominent, but when B exceeds ~ (2πme/elb), with lb = bunch length, effects of the resonance disappear. Thus short bunches and low B fields are required for observing the effect. We believe this accounts for the fact that this resonance has not been reported before in the electron cloud literature. The reason for the B field dependence, an explanation of the dynamics, and the results of the 2D simulations and of a single-particle tracking code used to elucidate details of the dynamics will be discussed, along with results from 3D simulations.