Recent Progress in the Performance of the Desy-Electron Synchrotron

During the first years of operation, primary emphasis was put on achieving reliability and stability. Of special note is the improvement in the slow extracted electron beams. More recently, installation of a "flat top" giving us an improvement of duty cycle from 4.5 % to 15.4 % (?E/E = ± 0.25 %) has motivated us to emphasize increase of beam intensity. Intensity dependant instabilities have been encountered, studied, and to some extent cured.