3MV加速器质谱测量^(36)Cl

^(36)Cl AMS Measurement With 3 MV Tandem Accelerator

在端电压为3MV的AMS装置上实现36 Cl及其他中重核素的高灵敏测量是AMS技术发展的重要方向之一。为进一步提高充气飞行时间探测方法中36S的压低能力,本文研究了36S和36 Cl在P10、异丁烷和丙烷气体中的能量歧离和角度歧离。在32MeV的入射能量下测量了几个地下水样品中36 Cl的含量,测量结果与72MeV能量下的测量结果相符。测量结果表明,采用充气飞行时间探测方法在3MV的串列加速器上测量36Cl时,探测限为36Cl/Cl≈10-14,当样品中36Cl/Cl≈10-13时测量不确定度为30%。

Developing the 36Cl and other medium heavy isotopes measurement at 3 MV AMS facilities is one of the vital trends in AMS measurement.To further increase suppression factor of 36S,the energy loss straggling and angular straggling of 36Cl and 36S ions in various counter gases（P10,isobutane and propane） were investigated.Some water samples were measured with the energy of 32 MeV,the results are in good agreement with the result by ion energy of 72 MeV.The results indicate that the detection limit of 36Cl with 3 MV AMS facility is approximately 36Cl/Cl≈10-14,and the uncertainty is 30% for the sample with isotopic ration 36Cl/Cl≈10-13.