报告题目：The Quest for a Nuclear Cock: First Results from Scandium-45

报告时间：2024-2-5

主办方：复旦大学 核科学与技术系/现代物理研究所、核物理与离子束应用教育部重点实验室、国家自然科学基金委-理论物理专款上海核物理理论研究中心

协办方: 《Nuclear Science and Techniques》&《核技术》刊物

摘要：Novel accelerator-based X-ray sources open new perspectives for research into new technologies as well as answering fundamental questions in nature. Using the radiation from the most intense X-ray laser, the European XFEL, we recently succeeded in exciting the sharpest atomic transition in the hard X-ray range which is the 12.4 keV nuclear resonance of the stable isotope scandium-45. We could determine the value of its resonance energy to an accuracy of 12 ppm, which is almost 3 orders of magnitude better than known before. With its extremely narrow natural linewidth of 1.4 femto-eV, it has the potential to become the most accurate nuclear clock ever. This has immediate applications for extreme metrology, in particular for research linked to the foundations of physics, such as time variations of the fundamental constants, the search for dark matter as well as probing the foundations of relativity theory.

报 告 人： Ralf Röhlsberger 教授

University of Jena (Germany)

报告人简介：Ralf Röhlsberger is a full professor of physics at University of Jena and a member of the directorate of the Helmholtz-Institute Jena, Germany. He is also a research group leader at DESY, Hamburg. He received his Ph.D. from the University of Hamburg. Following a postdoc appointment at the Advanced Photon Source, he was scientific assistant at the University of Rostock where he habilitated in 2002. After an interim professorship at the Technical University of Munich, he has been a senior scientist at DESY in Hamburg since 2003 and was deputy leader of the Experimental Facility Division at the PETRA III synchrotron radiation source project. From 2013 to 2020, he was a professor of physics at University of Hamburg, Germany. Since 2021, he is the elected chair of the International Board on the Applications of the Mössbauer Effect. His research interests include magnetism of thin films and nanostructures, quantum optics with X-rays, X-ray spectroscopy with synchrotron radiation, nuclear solid-state physics.