Design of a Hybrid Multiperiod Robinson Wiggler for TPS Light Source

A Robinson wiggler is designed to decrease the emittance within 1
$\text{nm} \cdot \text{rad}$
for Taiwan Photon Source. According to an analysis of the beam dynamics, decreasing the emittance with a multiperiod Robinson wiggler is more efficient than a single-period traditional Robinson wiggler. This wiggler consists of a dipole field and a strong gradient field, which creates a strong dynamic field integral multipole error. To enhance the gradient field and to have also a small dynamic field integral multipole error, a compensated side-pole design and an edge-pole shape in each pole are proposed in this paper. After optimization of the magnet, the dipole and gradient fields are 0.82 T and −37 T/m, respectively. The concept of the design of the magnetic circuit and the results of an analysis of the magnetic field are discussed herein.