In the realm of nuclear physics, a team of researchers led by Endre Takacs from the University of Tokyo, along with colleagues from various institutions including the University of York, Osaka University, and the University of Tennessee, has made a significant discovery regarding the charge radii of deformed rare earth nuclei. Their findings, published in the journal Nature Physics, shed new light on the nuclear structure and deformation of these elements, with potential implications for the energy sector, particularly in nuclear energy applications.
The nuclear charge radius is a crucial measure that provides insights into the structure and behavior of atomic nuclei. In their study, the researchers focused on the isotonic systematics of the deformed rare-earth region, specifically along the N=94 isotonic chain. They observed that odd-proton-number (odd-Z) nuclei are typically more compact than their even-proton-number (even-Z) neighbors, except for Lutetium (Lu), which previously appeared anomalously large compared to its neighbors Ytterbium (Yb) and Hafnium (Hf).
To resolve this longstanding anomaly, the researchers employed a high-precision method involving extreme-ultraviolet spectroscopy of highly charged Na-like and Mg-like ions. This technique, supported by high-accuracy relativistic atomic-structure calculations, allowed them to measure the natural-abundance-averaged Lu-Yb charge-radius difference with unprecedented precision. By combining this data with muonic-atom and optical isotope-shift measurements, they were able to reestablish a pronounced odd-even staggering along the N=94 isotonic chain.
The magnitude of this staggering was found to be unexpectedly large, far exceeding that observed in semi-magic nuclei and in deformed isotopic sequences. This finding challenges current nuclear density functional theory models, which failed to reproduce the enhanced staggering, suggesting that there may be missing structural effects in these models.
The practical applications of this research for the energy sector, particularly in nuclear energy, are significant. A better understanding of nuclear structure and deformation can lead to improved models for nuclear reactions and decay processes, which are crucial for the development of advanced nuclear reactors and the management of nuclear waste. Additionally, the precise measurement of charge radii can aid in the development of more accurate nuclear data libraries, which are essential for nuclear energy research and applications.
In conclusion, the research conducted by Takacs and his team provides valuable insights into the nuclear structure of deformed rare-earth nuclei, with potential implications for the energy sector. Their findings highlight the importance of precise measurements and advanced theoretical models in advancing our understanding of nuclear physics and its applications.
This article is based on research available at arXiv.