Practical Definitions of Beam Lifetimes in an Electron Storage Ring

This paper derives simple and accurate formulas breaking down a measured beam lifetime into its partial lifetimes of Touschek and beam-gas scattering. These formulas use only the measured data of beam lifetime and are as accurate as the lifetime measurement. These are useful as practical means, because the existing definitions of the two partial lifetimes often fail to give numerically accurate numbers due to the lack of accurate information of necessary parameters.