A high-current, high-voltage power supply with special output current waveform for APS injector synchrotron dipole magnets

The authors describe a high-voltage, high-current power supply for the injector synchrotron dipole magnets at APS (Advanced Photon Source). In order to reset the dipole magnets in each cycle, two different current waveforms are suggested. The first current waveform consists of three sections: DC-reset, linear ramp, and recovery sections where injection is done on the fly. The second current waveform consists of six different sections: DC-reset, transition to injection level, injection flat level, parabolic, linear ramp, and recovery sections. The effect of such waveforms on the beam is discussed, and the power supply limitations to follow such waveforms are given. The power supply limitations are due to the power components and control loops. The reference for the current loop is generated by a digital-to-analog converter. The injection on the fly method using a linear ramp that starts from an adjustable reset level and ramps to the evacuation level was selected. >