First results of a superconducting undulator on the ACO storage ring

A superconducting undulator has been fixed on the ACO storage ring. It has been observed that the electron beam is stable in the small gap of the vacuum chamber and unperturbed by the magnetic field of the undulator. Light emission has been observed at 140 and 240 MeV in the visible and ultra-violet. First results indicate that its geometrical as well as spectral distribution agree with theoretical predictions; small disagreements very probably arise from the fact that the electrons are not travelling exactly on the axis of the undulator.