ABSTRACT

The present study performed integral experiments of ⁹⁹Tc by an activation method using a fast-neutron source reactor ‘YAYOI’ of the University of Tokyo to validate evaluated nuclear data libraries: JENDL-4.0, ENDF/B-VII and VIII. Technetium-99 samples were irradiated with reactor neutrons using a pneumatic system, and repeated 74 times to accumulate statistics. Reaction rates of ⁹⁹Tc were obtained by measuring decay gamma rays emitted from ¹⁰⁰Tc. The fast-neutron flux spectrum at the YAYOI was checked with flux monitors and MCNP calculations. The experimental reaction rate of ⁹⁹Tc was compared with the reaction rates given using both the fast-neutron flux spectrum and evaluated nuclear data libraries. The present integral experiments supported the evaluated nuclear data library JENDL-4.0.

摘要

本研究使用东京大学的快中子源反应堆“YAYOI”通过激活方法对⁹⁹ Tc进行了积分实验，以验证评估的核数据库：JENDL-4.0、ENDF/B-VII 和 VIII。使用气动系统用反应堆中子照射锝 99 样品，并重复 74 次以累积统计数据。⁹⁹ Tc 的反应速率是通过测量从¹⁰⁰ Tc发射的衰变伽马射线获得的。用通量监测器和 MCNP 计算检查了 YAYOI 的快中子通量谱。实验反应率为⁹⁹Tc 与使用快中子通量谱和评估的核数据库给出的反应速率进行了比较。目前的积分实验支持评估的核数据库 JENDL-4.0。