Author: Stabile, A.
Paper Title Page
TUPRI047 Electromagnetic Modeling of Open Cell Conductive Foams for High Synchrotron Radiation Rings 1671
 
  • S. Petracca, A. Stabile
    U. Sannio, Benevento, Italy
  • A. Stabile
    INFN-Salerno, Baronissi, Salerno, Italy
 
  Open cell conductive foams (OCMF) have been recently suggested as an alternative to perforated metal patches for efficiently handling gas desorption from the beam pipe wall due to intense synchrotron radiation, yielding superior performance in terms of residual gas concentration and beam shielding. Experimental work is ongoing to assess their properties, including secondary emission yields and beam coupling impedances. In this communication we attempt a review of the Literature about electromagnetic modeling of OCMF, and outline a general framework for computing the surface impedance of OCMF walls and deriving the longitudinal and transverse beam coupling impedances thereof, based on effective medium theory and electromagnetic reciprocity. A critical analysis of the relevant modeling approximations is included.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI047  
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TUPRI048 A Map Approach for Electron Cloud Density in a Strong LHC Dipole 1674
 
  • S. Petracca, A. Stabile
    U. Sannio, Benevento, Italy
  • A. Stabile
    INFN-Salerno, Baronissi, Salerno, Italy
 
  The luminosity is limited by the electron cloud effects in presently running and proposed future storage rings. The evolution of the electron density during the electron cloud formation can be reproduced using a bunch-to-bunch iterative map formalism. By performing simulation codes this approach has been used to obtain a numerical prediction of the coefficients in the map, while in the presence of a magnetic field an analytic formula has been obtained for the linear coefficient. The next goal is finding a theoretical prescription of the quadratic coefficient at least in the presence of magnetic dipole. Then it will be possible to reproduce, by using the map formalism, the dynamics of electron cloud without performing the simulations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI048  
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WEPME033 Search for New e-cloud Mitigator Materials for High Intensity Particle Accelerators 2332
 
  • R. Cimino, S.T. O'connor, A.L. Romano
    INFN/LNF, Frascati (Roma), Italy
  • V. Baglin, G. Bregliozzi, R. Cimino
    CERN, Geneva, Switzerland
  • M.R. Masullo
    INFN-Napoli, Napoli, Italy
  • S. Petracca, A. Stabile
    INFN-Salerno, Baronissi, Salerno, Italy
 
  Electron cloud is an ubiquitous effect in positively charged particle accelerators and has been observed to induce unwanted detrimental impacts on beam quality, stability, vacuum etc. A great effort has been recently devoted to the search of new material morphology and/or coatings which can intrinsically mitigate beam instabilities deriving from electron cloud effects. In this context, we present some characterization of Cu foams, available from the market, and their qualification in terms of their vacuum behavior, impedance, secondary electron yield, gas desorption etc. More experimental effort is required to finally qualify foams as a mature technology to be integrated in accelerator environments. But, our preliminary results suggests that, when compatible with geometrical constrains, Cu foams can be utilized when low desorption yields are required and as e-cloud moderator in future particles accelerators.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPME033  
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