ESRF insertion devices, design considerations

The ESRF 6 GeV storage ring has been designed to provide a low-emittance lattice incorporating 32 straight sections, each 6 m long. Most of the straights will accommodate insertion devices, which will be the primary source of radiation. A review of the technology used to build them is given with the implications as to their performance. The effect of the insertion devices on the stored electron beam is discussed together with the consequences on the required field quality. The hard X-ray beams that will be generated are of unprecedented high spectral brilliance and power density. (orig.)