2026-01-29 アルゴンヌ国立研究所（ANL）
The ATLANTIS apparatus made extremely precise measurements of unstable ruthenium nuclei. (Image by Bernhard Maass/Argonne National Laboratory.)
＜関連情報＞
- https://www.anl.gov/article/how-does-probing-almondshaped-nuclei-help-push-the-boundaries-of-nuclear-physics
- https://journals.aps.org/prl/abstract/10.1103/81h5-wjkd
中性子過剰ルテニウムの電荷半径における三軸性の指紋 Fingerprints of Triaxiality in the Charge Radii of Neutron-Rich Ruthenium
Bernhard Maass, Wouter Ryssens, Kristian König, Michael Bender, Daniel P. Burdette, Jason Clark, Adam Dockery, Guilherme Grams, Max Horst et al.
Physical Review Letters Published: 10 November, 2025
DOI: https://doi.org/10.1103/81h5-wjkd
Abstract
We present the first measurements with a new collinear laser spectroscopy setup at the Argonne Tandem Linac Accelerator System, utilizing its unique capability to deliver neutron-rich refractory metal isotopes produced by the spontaneous fission of 252Cf. We measured isotope shifts from optical spectra for nine radioactive ruthenium isotopes 106–114Ru, reaching deep into the mid-shell region. The extracted charge radii are in excellent agreement with predictions from the Brussels-Skyrme-on-a-Grid models that account for the triaxial deformation of nuclear ground states. We show that triaxial deformation impacts charge radii in models that feature shell effects, in contrast to what could be concluded from a liquid drop analysis. This indicates that this exotic type of deformation should not be neglected in regions where it is known to occur, even if its presence cannot be unambiguously inferred through laser spectroscopy.
