Application of adaptive filtering algorithm to the stability problem for double crystal monochromator. Part I: Typical filtering algorithms

Abstract

The double crystal monochromator (DCM) is one of the critical beamline devices in synchrotron radiation facilities. With the continuous improvement of the performance of the X-ray beamline of synchrotron radiation sources and the constant application of fourth-generation synchrotron radiation sources, higher requirements for the stability of the DCM have been introduced. Based on previous engineering experience, the LN2 cooling system is the most critical factor affecting DCM’s stability. In this paper, the vibration suppression performance of FxLMS (filter-x Least Mean Square), FxNLMS(filter-x Normalized Least Mean Square), FxSDLMS(filter-x Sign-Data Least Mean Square), FxSELMS(filter-x Sign-Error Least Mean Square) and FxSSLMS(filter-x Sign-Sign Least Mean Square) are verified under Bragg@12.66 KeV and Bragg@9 KeV operating conditions for the measured vibration signals of DCM at SSRF(Shanghai Synchrotron Radiation Facility). The results show that the FxNLMS algorithm has higher convergence accuracy, excellent vibration suppression performance, and the ability to counter unknown disturbances compared with other typical filtering algorithms.