The Be window is destroyed by chance during using the Si(Li) detector.After it is repaired,the detector is used to measure characteristic X ray of following elements of V,Fe,Ni,Cu,Zn and Pb.The concomitent fake peak appears going with the photoelectric peak of above mentioned elements,and the ratio of two peaks’ energy is nearly a constant.By experiment test and reason analysis,it is found that the fare peak is resulted from Li ions’ contrary diraction drift in Si(Li) detector,which is caused by the suddenly sharp change of outward the degree of vacuum and high voltage.
