| 151Sm is one kind of long-lived (T1/2=90a) radionuclide. It is one of very important strong radioactive residue nuclides during nuclear waste processing and nuclear reactor operation, and the yield of the nuclear fission is 4%. Moreover, Sm nuclide belongs to lanthanide, in recent years along with the lanthanide resources developing and widespread application in the industry and agriculture and the stock raising as well as the medicine field, the lanthanide unceasing entered organism through the environment and the food chain. Therefore, the influence of lanthanide to environment, ecology and human health and forward biological effect research more and more arouse people interest and become the current important research topic. Realizing 151Sm AMS high sensitivity measurement is very important for research of long-lived nucleus behavior of transference and environment field. However, this nuclide has long half-life time, low content (in samples of biology, environment lanthanide content is especially lower, in biological sample lanthanide content generally in 10-6-10-9 magnitude), so using the conventional mass spectrum methods all with difficulties to realize the high sensitivity measurement of 151Sm. The Accelerator Mass Spectrometry (AMS) has ability of eliminating backgrounds and molecule-ion and isobar interference to cause the measurement limit to be reduced; has the high sensitivity (isotope ratio to be possible to reach～10-15), a little sample quantity (mg), short measurement time and other superiorities, it is possible to become a high sensitivity measurement method of 151Sm by AMS.This work has established the measurement method of 151Sm with Accelerator Mass Spectrometry on the HI-13 tandem accelerator at China Institute of Atomic Energy .The prime tasks include the detection system and the data-acquisition system. The main detectors are: multi-anodes ionization chamber, SBD detector and time of flight(TOF) detector. This thesis includes three kinds of detectors performance test and the actual improvement. On the high-energy side of the AMS facility, the beam was analyzed by a 90°analyzing magnet and a 15°electrostatic deflector. Then the 151Sm10+ ions were detected by a time of flight (TOF) detection system, and a silicon(Au) surface barrier detector (SBD) used as an energy detector (meanwhile as stop detector of TOF detection system). The flight length of the TOF detection system was 2.0m. The energy resolution of SBD was about 0.38% for 80MeV 151Sm. The time resolution of the TOF detector was less than 0.6 ns.This thesis introduces the measurement method of 151Sm by AMS, which includes the sample form choice, the conductive medium choice, the ion source beam extract out, the particle identification, the detector signal gain and the experimental data offline analysis and so on. After testing many times, the preliminary measurement method of 151Sm by using AMS was determined finally. Through chemical separation excludes the isobar 151Eu and the interference backgrounds during measurement. A result that the measurement sensitivity of 151Sm is about 10-8 is obtained at present.
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