Soreq Nuclear Research Center, Yavne, 81800, Israel; Unit of Nuclear Engineering, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel.
Soreq Nuclear Research Center, Yavne, 81800, Israel.
Appl Radiat Isot. 2022 Oct;188:110367. doi: 10.1016/j.apradiso.2022.110367. Epub 2022 Jul 8.
The absolute intensity for the 'prompt' 140.5 keV gamma-ray of Mo was evaluated using the β-γ coincidence technique. A liquid sample of Mo was prepared from aMo/Tc generator and measured in a 4παβ(LS)-γ(HPGe) system that comprises a Liquid Scintillator (LS) detector and a High-Purity Germanium (HPGe) detector. The sample was introduced into scintillation fluid embedded in a photo-reflector assembly that provides almost 100% efficiency for detecting β particles (in the energy range of intreset). The combination of the HPGe and the LS detectors provided a highly effective rejection mechanism for non-coincident events. Thereby, the distinction between the detected 140.5 keV events originating from decays of Tc (IT) and those from transitions bypassing the metastable state could be obtained and the 'prompt' intensity was evaluated directly. The system was calibrated for detecting β particles and γ-rays using radioactive sources of known activities and having identical geometry as the sample containing Mo. The absolute intensity of the 'prompt' 140.5 keV was found to be (5.21 ± 0.02±0.16)%, in good agreement with results from more recently reported works.
采用β-γ符合技术，对 Mo 的“瞬发”140.5keV 伽马射线的绝对强度进行了评估。Mo/Tc 发生器制备的液态 Mo 样品，在包含液体闪烁体（LS）探测器和高纯锗（HPGe）探测器的 4παβ(LS)-γ(HPGe)系统中进行了测量。该样品被引入到光反射器组件中的闪烁液中，该组件为探测β粒子（感兴趣的能量范围内）提供了近 100%的效率。HPGe 和 LS 探测器的组合为非符合事件提供了一种高效的排除机制。因此，可以区分源自 Tc（IT）衰变的检测到的 140.5keV 事件和绕过亚稳态的跃迁产生的 140.5keV 事件，并直接评估“瞬发”强度。该系统使用具有与含有 Mo 的样品相同几何形状的已知活度的放射性核素，对探测β粒子和γ射线进行了校准。发现“瞬发”140.5keV 的绝对强度为（5.21±0.02±0.16）%，与最近报道的结果非常吻合。
