CAJ | 학술논문

测定79 Se时由于79 Se尚无标准样品，需要建立79 Se/Se（79 Se、Se原子个数比，余同）的 AMS测量方法。在79 Se/Se的绝对测定中，为尽可能避免测量Se的同位素之间的差异，通常利用探测器测量79 Se离子，本文用法拉第筒对78 Se和80 Se进行测量，但这造成两个测量系统之间的系统误差。为避免这种系统误差，利用同一探测器测定79 Se、78 Se和80 Se。考虑到78 Se和80 Se的计数率非常高，在CIAE-AMS系统中的静电分析器前和靶室内安装衰减片以降低78 Se和80 Se的计数率。实验结果表明：通过两个衰减片的衰减作用，能将78 Se和80 Se的束流降低到半导体探测器的检测范围内，实现了样品中79 Se/Se的绝对测定，得到79 Se/Se为（2.08±0.10）×10-7，为准确测定79 Se半衰期奠定了基础。
측정79 Se시유우79 Se상무표준양품，수요건립79 Se/Se（79 Se、Se원자개수비，여동）적 AMS측량방법。재79 Se/Se적절대측정중，위진가능피면측량Se적동위소지간적차이，통상이용탐측기측량79 Se리자，본문용법랍제통대78 Se화80 Se진행측량，단저조성량개측량계통지간적계통오차。위피면저충계통오차，이용동일탐측기측정79 Se、78 Se화80 Se。고필도78 Se화80 Se적계수솔비상고，재CIAE-AMS계통중적정전분석기전화파실내안장쇠감편이강저78 Se화80 Se적계수솔。실험결과표명：통과량개쇠감편적쇠감작용，능장78 Se화80 Se적속류강저도반도체탐측기적검측범위내，실현료양품중79 Se/Se적절대측정，득도79 Se/Se위（2.08±0.10）×10-7，위준학측정79 Se반쇠기전정료기출。
As there is no 79 Se standard sample for measurement of 79 Se ,the characteriza-tions of 79 Se are conducted by isotope ratio of 78 Se/Se or 80 Se/Se since the abundances of 78Se and 80Se are well known .However ,beams of 78Se and 80Se both exceed the upper limit of semiconductor detector resulting in measurement failure .As a result ,attenua-tors were introduced into the CIAE-AMS system with the aim to measure the 79Se .The results indicate that the beam of 78 Se and 80 Se is decreased into the detecting range of semiconductor detector by two attenuators ,which would improve measurement sensitiv-ity and efficiency significantly .In addition ,the uncertainty of measurement is reduced greatly and it lays the foundation for the accuracy measurement of the half life of 79 Se .