Analysis of the Touschek lifetime and its application to the Pohang Light Source

The graph of measured beam lifetime as a function of time is analyzed based on the fact that the rate of change of the pure Touschek lifetime is exactly 1. The deviation from 1 of the rate of change of the measured beam lifetime is caused by the beam-gas scattering effect and the radiative electron beam polarization which can be expressed analytically. Comparing measured data with the analytic formulas, it is possible to estimate the beam-gas scattering lifetime and the polarization contribution to the beam lifetime. Further, it is possible to estimate the degree of polarization and its characteristic time constant.