EXPERIMENTAL DETERMINATION OF E-CLOUD SIMULATION INPUT PARAMETERS FOR DA?NE

DA?NE is an electron-positron collider with 1.02 GeV center of mass energy. For each circulating beam the maximum design current is 5 A. Preliminary simulations predicted e-cloud induced beam instabilities in the positron ring. Such calculations were based on literature results on aluminum reflectivity, photon yield, etc., not directly measured from the actual DA?NE chamber wall material. Here we show how calculations strongly depend on the assumed reflectivity and photon yield values. These two quantities have been measured using synchrotron radiation on samples prepared and made of the same aluminum alloy (Al 5083) used for the storage ring of DA?NE. The obtained experimental results are implemented in the calculations.