Design and test of a 5 T superconducting wiggler

A description is given of a superconducting wiggler built and tested at Saclay for the Laboratoire pour l´Utilisation du Rayonnement Electromagnetique (LURE) at Orsay, France. The wiggler is being used as light source on the 1.72-GeV positron beam of the DCI storage ring at Orsay to increase the photon flux at short X-ray wavelengths. The magnet has five half-periods of field with a central amplitude of nearly 5 T, two middles with -3.6 T, and two ends with 2 T. The period length is 260 mm, the magnet gap is 67 mm, and the room-temperature beam chamber gap is 30 mm. The field is produced by ten superconducting coils embedded in a soft iron yoke which contains the magnetic forces. A correction current is applied to the end coils to ensure a zero integral field in the whole range of field. The results of three magnet training tests are briefly discussed.