In an in-vacuum undulator, the dynamic phase error, which is a kind of systematic phase errors, is increased because the out-of-vacuum girder is deformed with a strong magnetic force. As a result, the spectral performance of synchrotron radiation is deteriorated. A recommended solution for a problem of this kind is to adopt a spring system to compensate the magnetic force, but a conventional spring system has a problem in that the mechanical frame of the undulator is deformed by a reaction force from the springs. The new force-compensating spring module shown in this paper is a self-contained type that can treat the spring reaction force within the module, therefore, the side effects of the spring operation can be minimized. Three in-vacuum undulators with a length of 2–4 m are equipped with the spring modules of new type, so a small rms phase error of 1.7°–2.2° is obtained under the highest magnetic force at the minimum gap.

在真空波荡器中，由于非真空梁在强磁力作用下变形，动态相位误差是一种系统相位误差。结果，同步辐射的光谱性能恶化。针对此类问题，推荐的解决方案是采用弹簧系统来补偿磁力，但传统的弹簧系统存在的问题是波荡器的机械框架会因弹簧的反作用力而变形。本文所示的新型力补偿弹簧模块是一种独立类型，可以在模块内处理弹簧反作用力，因此可以最大限度地减少弹簧操作的副作用。三个长度为2-4 m的真空波动器配备了新型弹簧模块，