Kei Minamisono

Adjunct Professor of Physics, Research Senior Scientist


Education and training

  • MS, Physics, Osaka University, 1996
  • PhD, Physics, Osaka University, 1999


What is the most fundamental property of a nucleus? Arguably, the size or shape of the nucleus is one of them. My current research interests is to determine the size, shape or radius of a rare nucleus that occurs at/near the existence limit of nuclei. The size of a nucleus tells us how nucleons are distributed inside a nucleus. It is essential to gain critical insights into the driving nuclear forces of structural changes compared to stable nuclei surrounding us. Therefore, the size of a nucleus is driven by the nuclear equation of state (EoS). The EoS determines the nature of dense nuclear matter, like nucleus itself and neutron stars, which is not well understood yet. It is remarkable that a terrestrial laser spectroscopy experiment at the level of a nucleus addresses astronomical properties of a neutron star


I spent my childhood in a small town in Kyoto, a historical city in Japan. There are a lot of shrines, temples, and historic spots in my hometown, where I often visited for a walk. After graduating high school in Kyoto, I went to Osaka University for my graduate studies. I obtained a Doctor of Science in nuclear physics in 1999, had two postdoc positions in Osaka and TRIUMF in Canada, and arrived at MSU in 2004. I am an experimentalist, and like to see responses of nature to understand what is happening. My current interest is to measure size/shape of radioactive nuclei, especially at the existing limit of nuclides using laser-assisted precision techniques. This leads to understandings of underlying nuclear forces and the nuclear equation of state for example characters of neutron stars.

How students can contribute as part of my research team

A student in my group is typically responsible for one development project and one laser spectroscopy experiment where the student runs experiments, analyzes data, interprets results and writes papers. Students will have training opportunities to gain hands-on experience in running laser spectroscopy experiments for nuclear structure studies. We currently use the laser-resonant fluorescence and laser-resonant ionization techniques. We often run offline laser spectroscopy experiments with stable beams produced locally, in addition to online experiments with radioactive beams. The experimental system includes but is not limited to the operation of various laser systems (CW and pulsed), the ion-beam production from offline ion sources, the ion-beam transport, and the data acquisition system.

Scientific publications