Researcher Information

KIMURA Masaaki


Uncovering the origin of the matter from the property of atomic nucleus

Department of Physics, Nonlinear Physics


I am interested in the origin of the matter in our universe. For this reason, I am constructing the theoretical models for atomic nuclei and performing the numerical simulations. I also research and develop the nuclear reaction database for the safely and peaceful use of nuclear power.

FieldNuclear structure, Steller nuclear reactions, Nuclear reaction database
KeywordUnstable nuclei, Hypernuclei, Cluster resonances, Nucleosynthesis, Steller nuclear reactions, Nuclear fusion, Molecular dynamics, Nuclear reaction database

Introduction of Research

The properties of unstable nuclei and hypernuclei are closely related to the astrophysical phenomena such as supernova and neutron star merger, which are the key to uncover the origin of the matter in our universe.
To study these exotic nuclei, I have developed and extended the aytisymmetrized molecular dynamics model and performed the numerical simulations for atomic nuclei by using the massive supercomputer (Figure. “Numerical simulation for dynamics of three He4 nuclei”). I have studied the stability and shape of unstable nuclei (Figure. “Various shape of unstable nuclei”), and impurity effect of hypernuclei (Figure. “Structure change caused by impurity effect”). Recently, I also launched the research project to study the cluster resonances which are related to the nucleosynthesis in the stars.
Besides these fundamental researches, I organize the Nuclear Reaction Data Center in Hokkaido University (JCPRG) for the research & development of the nuclear reaction database. We are joining the international nuclear reaction database network, which is managed by international atomic energy agency (IAEA), and we compile EXFOR database for all nuclear reaction experiments performed in Japanese facilities (Figure. ”Database for 113th element ‘Nihonium’”).
My goals are the understanding the basic properties of atomic nuclei and the contribution to the peaceful and safety usage of the nuclear power.

Motion of three Helium-4 nuclei obtained by the numerical simulation. It represents the excited states of Carbon-12 nucleus.
Various exotic shapes of Salfur-43 nucleus
Impurity effect changes the parity of a hypernucei
Part of the database for the first original paper of 113th element, Nihonium

Representative Achievements

Antisymmetrized Molecular Dynamics: a new insight into the structure of nuclei, Y. Kanada-En'yo, M. Kimura and H. Horiuchi, Comptes Rendus Physique 4, 497 (2003).
Deformed-basis antisymmetrized molecular dynamics and its application to 20Ne, M. Kimura, Physical Review C69, 044319 (2004).
16O+16O molecular nature of the superdeformed band of 32S and the evolution of the molecular structure, M. Kimura and H. Horiuchi, Physical Review C69, 051304 (2004).
Deformation of hypernuclei studied with antisymmetrized molecular dynamics, M. Isaka, M. Kimura, A. Dote and A. Ohnishi, Physical Review C83, 044323 (2011).
Determination of the Structure of Ne-31 by a Fully Microscopic Framework, K. Minomo, T. Sumi, M. Kimura, K. Ogata, Y. R. Shimizu and M. Yahiro, Physical Review Letters 108, 052503 (2012).

Related industries

Nuclear engineering
Academic degreePh. D.
Self Introduction

My hometown is seaside town in Okayama.
When I was a child, I wanted to be an astronaut, but eventually I became a researcher. Being a researcher is rather nice, because I can travel to various countries in the world and I can have many friends all over the world

Academic background1997: Bachelor, Faculty of science, Kyoto University
1999: Master thesis, Department of Physics, Kyoto University
2002: Ph. D, Department of Physics, Kyoto University
2002-2005: Special Postdoctoral Researcher, RIKEN, Wako, Japan
2005-2006: Postdoctoral fellow, Yukawa Institute for Theoretical Physics, Kyoto Univ., Kyoto, Japan.
2006-2008: JSPS Postdoctoral fellow, Department of Physics, Tsukuba Univ., Tsukuba, Japan.
2008-2012: Tenure-Track Assistant, Creative Research Institution, Hokkaido Univ., Sapporo, Japan
2012- :Associate Professor, Department of Physics, Hokkaido Univ., Sapporo, Japan
2017-: Nuclear reaction data center, Center head
ProjectGrant-In-Aid for Scientific Research on Inovvative Areas "nuclear matter in neutron stars investigated by experiments and astronimical observations"
Room addressScience Building No.2 #2-10-08

Department of Physics, Nonlinear Physics

KIMURA Masaaki


What is your dream that you want to achieve through your research?

I hope to have a fun and productive research life. We know that research usually does not go well (I think that’s why it’s worth studying), but I want to find some joy in it every day, such as “I had a small realization of a small fact” or “I summarized a mathematical formula beautifully.” My best hope is that the accumulation of such small joys leads to some discovery.

What is the research theme that you are currently focusing on?

I am studying nuclear fusion reactions. All the elements around us are produced by nuclear fusion reactions in various astronomical phenomena of the universe. The planets and our bodies are also made from the “cinders” of these astronomical nuclear reactions. Although it is difficult to reproduce these nuclear reactions in the laboratory, we are theoretically studying and numerically simulating these reactions to understand the origin of the elements.

Fig: (Left) The calculated fusion reaction rate of 12C+12C reaction.
(Right) The fusion of oxygen and carbon nuclei calculated by numerical simulation.
What made you decide to become a researcher?

When I was in elementary school, the American planetary probes Voyager 1 and 2 took pictures of Jupiter and Saturn and sent them to Earth. I was so impressed when I saw them on TV, and I think that was the first time I wanted to be a scientist. To be honest, I wanted to be a baseball player, an astronaut, or a pilot, but being a scientist is not so bad.