Demonstration of high-performance pole pieces made of monocrystalline dysprosium for short-period undulators

Reported here are the results of experiments carried out to demonstrate the magnetic performance of dysprosium (Dy) to enhance the capability of undulators. Tiny pieces of monocrystalline Dy surrounded by permanent magnets (PMs) work as pole pieces (PPs) to concentrate the magnetic flux, when cooled down below the Curie temperature of 85   K. A PP made of Dy is much more attractive than one made of a conventional material, because its saturation magnetization is much higher. Furthermore, it also allows for a more flexible selection of PM material, potentially leading to further enhancement of the performance of short-period undulators. Besides these advantages, practical issues related to using Dy PPs and countermeasures against them are discussed.

Source: Journal of Synchrotron Radiation - June 17, 2019 Category: Physics Authors: Tanaka, T. Kagamihata, A. Tags: short-period undulators high-performance pole pieces monocrystalline dysprosium research papers Source Type: research