Features of the Longitudinal Electron Friction Force in Experiments on COSY Synchrotron

The cooling system for the COSY-Julich synchrotron features currently the energy highest among electron cooling devices with a strong longitudinal magnetic field, which has been tested in actual experiments. In the system, the cooling process was observed in a wide range of electron beam energies from 100 keV to 1.256 MeV. A large number of experimental observations regarding the physics of electron cooling have been collected at an energy of 908 keV. The experience of longitudinal electron cooling at high energies is discussed and various experimental facts are described.