A compact APPLE undulator at TPS

Abstract In order to meet user demand for circularly polarized light from the bending magnet and effectively utilize the straight sections at the Taiwan Photon Source, it is necessary to make improvements. Thus, we designed and constructed an APPLE-II (Advanced Planar Polarized Light Emitting) type EPU with a total length of 0.8 meters. This required new considerations of the overall design, especially the phase movement mechanism, and the feasibility of subsequent maintenance work. This paper will provide an explanation on the design considerations, construction and magnetic field measurement results for this EPU.