Abstract Detection of fissile and fertile materials and their accountability is important for nuclear safeguards. This paper reports detection of 238U and 235U in the same experimental setup using passive and pulsed neutron source based active coincidence methods respectively. The coincidence analysis has been carried out using a time stamp data acquisition system. Furthermore, the paper reports the fast ever detection of 235U using D-T pulsed neutron source based active coincidence method along with time stamp data acquisition system. In this study, 142.86 gm 238U and 1 gm 235U have been detected successfully using passive and pulsed neutron source based active coincidence methods with 6000 s and 400 s time stamp data respectively acquired using only eight 3He detectors of 45 cm active length. Furthermore, the present research methodology can be extended for the detection of Plutonium. This work will also be of importance towards detection of small quantity of SNM in cellulose waste from nuclear material processing facilities.

中文翻译：

---

使用基于被动和脉冲中子源的主动符合方法检测特殊核材料 (SNM)

摘要 易裂变材料和可转化材料的检测及其问责对于核保障很重要。本文报告了在同一实验装置中分别使用基于被动和脉冲中子源的主动符合方法检测 238U 和 235U。使用时间戳数据采集系统进行了重合分析。此外，该论文还报告了使用基于 DT 脉冲中子源的主动符合方法以及时间戳数据采集系统对 235U 的快速探测。在这项研究中，142.86 gm 238U 和 1 gm 235U 已使用基于被动和脉冲中子源的主动符合方法成功检测到，分别使用 8 个 45 cm 有效长度的 3He 探测器分别获取了 6000 s 和 400 s 时间戳数据。此外，目前的研究方法可以扩展到钚的检测。这项工作对于检测来自核材料加工设施的纤维素废物中的少量 SNM 也很重要。