1.Introduction Engineering science and technology is an important driving force in changing the world,and engineering frontiers(here referred to as“engineering fronts”)are important guidelines for future directions ...1.Introduction Engineering science and technology is an important driving force in changing the world,and engineering frontiers(here referred to as“engineering fronts”)are important guidelines for future directions in the development of engineering science and technology.Grasping trends in global engineering science and technology and quickly adapting to new directions in the current scientific and technological revolution have become strategic choices for countries all over the world.Since 2017,the Chinese Academy of Engineering has organized the Engineering Fronts research project,together with Clarivate Analytics and Higher Education Press,with the hope of bringing together the expert knowledge of global engineering and technology talents,assessing global frontiers in engineering research and development,and developing strategic opportunities to provide a reference for active responses to global challenges and sustainable development.展开更多
Based on the time-dependent coincidence method, a preliminary experiment has been performed on uranium metal castings with similar quality （about 8-10 kg） and shape （hemispherical shell） in different enrichments u...Based on the time-dependent coincidence method, a preliminary experiment has been performed on uranium metal castings with similar quality （about 8-10 kg） and shape （hemispherical shell） in different enrichments using neutron from Cf fast fission chamber and timing DT accelerator. Groups of related parameters can be obtained by analyzing the features of time-dependent coincidence counts between source-detector and two detectors to charac- terize the fission signal. These parameters have high sensitivity to the enrichment, the sensitivity coefficient （defined as （AR/Am）/f-t） can reach 19.3% per kg of 235U. We can distinguish uranium castings with different enrichments to hold nuclear weapon verification.展开更多
文摘1.Introduction Engineering science and technology is an important driving force in changing the world,and engineering frontiers(here referred to as“engineering fronts”)are important guidelines for future directions in the development of engineering science and technology.Grasping trends in global engineering science and technology and quickly adapting to new directions in the current scientific and technological revolution have become strategic choices for countries all over the world.Since 2017,the Chinese Academy of Engineering has organized the Engineering Fronts research project,together with Clarivate Analytics and Higher Education Press,with the hope of bringing together the expert knowledge of global engineering and technology talents,assessing global frontiers in engineering research and development,and developing strategic opportunities to provide a reference for active responses to global challenges and sustainable development.
文摘Based on the time-dependent coincidence method, a preliminary experiment has been performed on uranium metal castings with similar quality （about 8-10 kg） and shape （hemispherical shell） in different enrichments using neutron from Cf fast fission chamber and timing DT accelerator. Groups of related parameters can be obtained by analyzing the features of time-dependent coincidence counts between source-detector and two detectors to charac- terize the fission signal. These parameters have high sensitivity to the enrichment, the sensitivity coefficient （defined as （AR/Am）/f-t） can reach 19.3% per kg of 235U. We can distinguish uranium castings with different enrichments to hold nuclear weapon verification.
