Insertion devices at the ESRF

Fifteen undulators and wigglers are now installed on the ESRF. They have been designed and measured in‐house. The magnetic field has been corrected using iron shims which remove all multipoles and fully corrects the radiation spectrum. The measured spectra confirm the expected low emittance of the beam resulting in an unprecedented high brilliance above 10 keV of photon energy. The observed interaction with the electron beam is negligible.