Japan Synchrotron Radiation Research Institute, Koto 1-1-1, Sayo, Hyogo 679-5198, Japan.
RIKEN SPring-8 Center, Koto 1-1-1, Sayo, Hyogo 679-5148, Japan.
Phys Rev Lett. 2018 Sep 21;121(12):124801. doi: 10.1103/PhysRevLett.121.124801.
The undulator is a magnetic device usually consisting of a series of rare-earth permanent magnets (REPMs) arranged to generate a sinusoidal magnetic field, and is installed in synchrotron radiation and free electron laser facilities to periodically deflect high-energy electrons. Because the undulator is operated under a high-radiation environment, it is important to take possible measures to avoid the quality degradation, in particular the radiation damage of REPMs. We present a simple scheme to enhance the radiation resistance of REPMs in undulators, in which the easy axis of each REPM is tilted by 45°. Experimental studies have revealed that the radiation resistance of REPMs in this configuration is enhanced by an order of magnitude compared to that in the conventional undulator.
波荡器是一种磁体装置，通常由一系列稀土永磁体（REPMs）组成，用于产生正弦磁场，并安装在同步辐射和自由电子激光设施中，以周期性地偏转高能电子。由于波荡器在高辐射环境下运行，因此采取可能的措施来避免质量下降，特别是避免稀土永磁体的辐射损伤是很重要的。我们提出了一种简单的方案来提高波荡器中稀土永磁体的辐射抗性，其中每个稀土永磁体的易磁化轴倾斜 45°。实验研究表明，与传统波荡器相比，这种结构中稀土永磁体的辐射抗性提高了一个数量级。
