Insertion device development for a broad range of radiation properties

On intermediate energy synchrotron radiation light sources, a broad spectral range can be covered by a wide panoply of insertion devices, from long period electromagnetic systems to short period in vacuum undulators. Furthermore, in-vacuum wiggler can be developed as an alternative to superconduting ones. The effects on the electron beam, also more critical at low electron beam energies, require specific care on the magnetic field multipolar terms and can include direct compensation of the dynamical integral. In addition, for field enhancement at short period, cryogenic undulators are now currently developed, with a recently installed PrFeB based undulator at SOLEIL. Besides, variable polarisation can be provided with APPLE-II type undulators, with possible aperiodicity. Rapid switching can be achieved with electromagnet/permanent magnet undulator using copper sheets coils.