X 射线自由电子激光装置是当代科学研究的重要平台，但有规模巨大和成本高昂等问题，因此紧凑型XFEL成为一个研究热点，减小波荡器周期是紧凑型XFEL发展的重要方向之一。虽然已经提出并发展了超导波荡器、真空波荡器、低温波荡器和微波波荡器等多种类型的波荡器，但是依然难以同时满足小周期和高场强的要求。基于螺线管的错列波荡器在10 mm周期下，峰值场强可高达1.08 T，具有很大应用价值，但是超导螺线管所需的低温条件限制了其推广应用。鉴于NdFeB永磁材料在室温具有优良的磁性能，本课题提出用NdFeB材料来取代超导螺线管的思路，并完成以下研究内容：建立基于NdFeB永磁材料的小周期错列波荡器物理模型；研究该模型中的磁场规律；通过实验来验证模型和磁场规律的正确性；探讨该模型用于紧凑型XFEL的可行性。这一波荡器物理模型若能成功建立，将提供一种减小波荡器周期的新方案，对XFEL 装置的小型化有推动作用。

X-ray free electron laser facility is an important platform of contemporary scientific research, but has the problems of large scale and high cost. So, the compact XFEL becomes a research hotspot and the reduction of undulator period is one of the important directions of the development of the compact XFEL. Although various types of undulators, such as superconducting undulator, in-vacuum undulator, cryogenic permanent magnet undulator and microwave undulator et. al., have been proposed and developed, it is still difficult to meet the requirements of mini-period and high field strength. The peak field of solenoid-derived undulator with 10 mm period is up to 1.08 T, and shows great application value. But low temperature required by superconducting solenoid limits its popularization and application. In this project, seeing the high magnetic properties of NdFeB permanent magnetic material at room temperature, it is proposed to replace the superconducting solenoid by NdFeB, and we will fulfill the following research contents: establishment of physical model of mini-period NdFeB-derived staggered undulator, research on the magnetic field rules in the physical model, verification of the physical model and the magnetic field rules and feasibility discussion for the compact XFEL. If the undulator physical model can be established successfully, a new scheme for reducing the undulator period will be provided, which will promote the development of compact XFEL.