


Zensho Yoshida / Professor / Division of Transdisciplinary Sciences 

Department of Advanced Energy / / Plasma Physics, Nonlinear Science, Fusion Energy
http://www.ppl.k.utokyo.ac.jp/




Career Summary 
1980: Graduated, Faculty of Engineering, The University of Tokyo 198283: Graduate student at Courant Institute of Mathematical Sciences, NYU 1985: Doctor of Engineering from The University of Tokyo 1985: Lecturer, The University of Tokyo 1986: Associate Professor, The University of Tokyo 1999: Professor, The University of Tokyo




Educational Activities 
Graduate school: Nonlinear Science, Basic Course on Plasma Physics Faculty of Engineering: Applied Physics I ~ IV




Research Activities 
Diversity of the universe, which has seemed insuperable in previous approaches, may take on a new character in the context "nonlinear science" and the theory of gcollective phenomenah  the paradigm of physics is "plasma". There are many exciting problems in the scope; Examples are the catastrophic eruption of plasma (solar flare) at the sun surface, the corresponding activity of aurora, chaotic (partially periodic and partially random) emissions from pulsars, and the creation of spectacular spiral patterns in galaxies. The aim of our study is to explore the diversity of plasma structures in nature. They will provide us with hints of essential ingredients needed to produce fusion plasmas (an ultimate energy source) or antimatter plasmas. Our recent researches are focused on the interesting structures emerging from "flows" in plasmas.
Figure 1: Theoretical model of Jupiter's magnetosphere. A high energydensity plasma is confined by the hydrodynamic pressure of highspeed rotation.
Figure 2: Pureelectron plasma confined by the "magnetosphere" of the ProtoRT device. By controlling the electric field potential (b), stable confinement has been demonstrated.

Literature
1) Z. Yoshida, "Mathematical Physics of Collective Phenomena" (Iwanami, 1995), Monograph in Japanese. 2) Z. Yoshida, "Introduction to Nonlinear Science" (Iwanami, 1998), Monograph in Japanese. 3) Z. Yoshida, "Applied Functional Analysis", new edition, (Saiensu, 2006), Monograph in Japanese. 4) Z. Yoshida, "Nonlinear Science The Challenge of Complex Systems" (SpringerVerlag, BerlinHeidelberg, 2010), Monograph. 5) Z. Yoshida and Y. Giga, Remarks on spectra of operator rot, Math. Z. 204 (1990), 235245. 6) Z. Yoshida, H. Asakura, H. Kakuno, J. Morikawa, K. Takemura, S. Takizawa, and T. Uchida, Anomalous resistance Induced by chaos of electron motion, Phys. Rev. Lett. 81 (1998), 245246. 7) S.M. Mahajan and Z. Yoshida, Double curl Beltrami flow  diamagnetic structures, Phys. Rev. Lett. 81 (1998), 48634866. 8) Z. Yoshida and S.M. Mahajan, Variational principles and selforganization in twofluid plasmas, Phys. Rev. Lett. 88 (2002), 095001. 9) Z. Yoshida, H. Saitoh, J. Morikawa, Y. Yano, S. Watanabe and Y. Ogawa, Magnetospheric vortex formation: selforganized confinement of charged particles, Phys. Rev. Lett. 104 (2010), 235004 14. 10) Z. Yoshida and P. J. Morrison, Epitwodimensional fluid flow: A new topological paradigm for dimensionality, Phys. Rev. Lett. 119 (2017), 244501 15.




Other Activities 
Chern Professor, Mathematical Science Reseach Institute (Berkeley, USA)(2018). Course Director of the College of Plasma Physics, International Center for Theoretical Physics (Trieste, Italy) (1998). President, Japanese Society of Plasma and Fusion Research (20172019). Chairman of Division 2 (plasma physics), Japanese Physical Society (20032004). EditorinChief, Journal of Plasma and Fusion Research (20042006), Editor, Progress of Theoretiucal and Experimental Physics. Science Advisor, MEXT, Government of Japan (20042010). Member of Science Council of Japan (2017).




Future Plan 
The RT1 project is aiming at developing an innovative method of plasma confinement. The exploration includes many different pathbreaking challenges of both experimental and theoretical physics. For example, the study of equilibrium and stability of flowing plasma needs development of new methods of mathematical analysis. The central theme of recent research is the effect of "flows" in plasmas. A novel definition of "plasma", which we are proposing, is a nonlinear coupling of matter and field (the electromagnetic field is the most important element, but other fields of interactions may also be included in astronomical or highenergy systems). A flow, representing a collective motion of matter, is seemed as a nonlinear field interacting with other fields representing forces. The coupled dynamics has interesting noncanonical, nonHermitian, multiscale properties, which are underlying a variety of unknown structures and phenomena in the universe.
Figure 3: RT1 device. A superconducting magnet is levitated in the vacuum chamber, producing a dipole magnetic field and creating a magnetospheric plasma configuration in the laboratory.
Figure 4: Laboratory magnetosphere plasma produced by the RT1 device.




Messages to Students 
Physical and mathematical sciences have developed elegant foundations and sophisticated methodologies, which are prerequisites for students and young researchers to challenge new problems. One might feel that the frontier is rather far to reach. But, nonetheless, there are a plenty of exciting problems that will need totally innovative ideas of young generation.










