近日，德国美因茨亥姆霍兹研究所的Sebastian Raeder&Jessica Warbinek及其研究团队取得一项新进展。经过不懈努力，他们揭示镄电荷半径的平滑趋势和壳效应的影响。相关研究成果已于2024年10月30日在国际权威学术期刊《自然》上发表。
本文报道了沿镄（Z=100）同位素链的激光光谱测量结果，并扩展了关键区域内锘（Z=102）同位素链的数据。研究人员采用多种产生方案和不同的先进技术，来确定原子跃迁中的同位素位移，并据此提取了核均方电荷半径的变化。
基于能量密度泛函的一系列核模型很好地再现了观察到的核尺寸平滑演化现象。模型预测的高度一致性以及对不同同位素预测结果的相似性都表明，与较轻的原子核相比，在这一区域中壳层效应对核尺寸的影响有所减弱，正逐步过渡到一个新的状态。
据悉，量子力学的核壳层结构决定了，具有大量质子数（Z≥100）的最重核素的稳定性和存在极限。正如较轻核素的激光光谱研究所示，壳层效应也会影响原子核的大小和形状。然而，关于重锕系元素的电荷半径和核矩的实验信息很少。重锕系元素将自然界中最重的核素与人工制造的超重元素联系起来。
附：英文原文
Title: Smooth trends in fermium charge radii and the impact of shell effects
Author: Warbinek, Jessica, Rickert, Elisabeth, Raeder, Sebastian, Albrecht-Schnzart, Thomas, Andelic, Brankica, Auler, Julian, Bally, Benjamin, Bender, Michael, Berndt, Sebastian, Block, Michael, Brizard, Alexandre, Chauveau, Pierre, Cheal, Bradley, Chhetri, Premaditya, Claessens, Arno, de Roubin, Antoine, Devlin, Charlie, Dorrer, Holger, Dllmann, Christoph E., Ezold, Julie, Ferrer, Rafael, Gadelshin, Vadim, Gaiser, Alyssa, Giacoppo, Francesca, Goriely, Stephane, Gutirrez, Manuel J., Harvey, Ashley, Hasse, Raphael, Heinke, Reinhard, Heberger, Fritz-Peter, Hilaire, Stephane, Kaja, Magdalena, Kaleja, Oliver, Kieck, Tom, Kim, EunKang, Kneip, Nina, Kster, Ulli, Kraemer, Sandro, Laatiaoui, Mustapha, Lantis, Jeremy, Lecesne, Nathalie, Loria Basto, Andrea Tzeitel, Mistry, Andrew Kishor, Mokry, Christoph, Moore, Iain, Murbck, Tobias, Mnzberg, Danny, Nazarewicz, Witold, Niemeyer, Thorben, Nothhelfer, Steven, Pru, Sophie, Raggio, Andrea, Reinhard, Paul-Gerhard, Renisch, Dennis, Rey-Herme, Emmanuel, Romans, Jekabs, Romero Romero, Elisa, Runke, Jrg
Issue&Volume: 2024-10-30
Abstract: The quantum-mechanical nuclear-shell structure determines the stability and limits of the existence of the heaviest nuclides with large proton numbers Z100 . Shell effects also affect the sizes and shapes of atomic nuclei, as shown by laser spectroscopy studies in lighter nuclides. However, experimental information on the charge radii and the nuclear moments of the heavy actinide elements, which link the heaviest naturally abundant nuclides with artificially produced superheavy elements, is sparse. Here we present laser spectroscopy measurements along the fermium (Z=100) isotopic chain and an extension of data in the nobelium isotopic chain (Z=102) across a key region. Multiple production schemes and different advanced techniques were applied to determine the isotope shifts in atomic transitions, from which changes in the nuclear mean-square charge radii were extracted. A range of nuclear models based on energy density functionals reproduce well the observed smooth evolution of the nuclear size. Both the remarkable consistency of model prediction and the similarity of predictions for different isotopes suggest a transition to a regime in which shell effects have a diminished effect on the size compared with lighter nuclei.
DOI: 10.1038/s41586-024-08062-z
Source: https://www.nature.com/articles/s41586-024-08062-z
来源：科学网 小柯机器人