151Sm(半衰期90a)属于稀土元素,它在工业、农业、国防等应用研究中占有重要地位,研究其对环境和人体健康的影响非常重要。因其在样品中、尤其在生物样品中含量很低(只有10-6～10-9),所以加速器质谱(AMS)成为实现其高灵敏测量的有效方法。AMS测量要求离子源引出的束流尽可能大而 151Sm (half-life 90a) belongs to the rare earth element. It occupies an important position in the applied research of industry, agriculture and national defense. It is very important to study its impact on the environment and human health. Because of its low content in the sample, especially in biological samples (only 10-6 ~ 10-9), accelerator mass spectrometry (AMS) is an effective method to achieve its highly sensitive measurement. The AMS measurement requires that the beam from the ion source be as large as possible