Electron cooling at CRYRING with an expanded electron beam

Studies of electron cooling with an adiabatically expanded electron beam have been performed at CRYRING. Measurements of the longitudinal drag force using three different methods are described and are compared with measurements at other electron coolers. The processes that determine the electron temperature, longitudinally and transversally, are reviewed, and the effect of the beam expansion on these processes is discussed. It is described how the electron temperature can influence the outcome of recombination measurements, and how such measurements can be used to determine the electron temperature, and an example of such a measurement is given.