ENERGY CALIBRATION OF THE ELECTRON BEAM OF THE ALS USING RESONANT DEPOLARISATION*

with high precision using resonant depolarization. In a stor-age ring where the beam lifetime is dominated by large-angle intrabeam (Touschek) scattering, the relative beam polarization can be measured by relative changes in the beam lifetime because of the dependence of the Møller scattering rate on the polarization. In the fully Touschek-dominated regime, the change in lifetime at the ALS due to a complete depolarization is larger than 10%. The en-ergy calibration has been used at the ALS to perform high precision measurements of the machine stability, machine reproducibility and the momentum compaction factor.