R&D for a minigap undulator at LURE

An in-vacuum minipole (short period) Insertion Device has been developed at LURE (Laboratoire pour l'Utilization du Rayonnement Electromagnetique) in the frame of R&D. A particular attention has been especially taken in the design and the mechanics in order to ease the cancellation of magnetic errors which affect the performances of the ID. The magnetic field (0.68 T) is produced by two arrays of permanent magnets installed on a fixed gap frame. Each magnet can be vertically moved in order to correct multipolar errors and phase errors. In addition, end correctors have been especially designed to increase the efficiency of the multipolar correction. In this paper, the authors present the design of the undulator, the mechanical choices as well as the calculations and the vacuum tests.