Transverse Electron Cooling from the Time Evolution of the Profiles to Drift Velocities of the Oscillation Amplitudes

When a beam in a synchrotron is subjected to transverse cooling, the betatron oscillation amplitudes of the individual particles are reduced. A method to establish the velocity of the amplitude reduction as a function of the amplitude itself has been developed. The beam profile can be measured along the cooling process with for example beam ionisation monitors. From successive profiles one computes the time evolution of the amplitude distribution, which in turn allows the determination of the amplitude reduction velocity. This method could be applied to investigate the influence of the transverse electron temperature on electron cooling performance.