Quantum and Beam Science

Exploration of the microscopic world and construction of advanced nanotechnology using quantum beams

The inherent properties and characteristics of matter are fundamentally governed by the behavior and reactions of atoms and molecules within matter. We conduct research aimed at precisely understanding the properties of materials at the nanoscale using quantum beams, and we strive to create advanced nanotechnologies based on quantum beams. Through this, we develop the field of quantum beam science in life science, material science, and space science.

Academic Staff

Manabu SAITO

Manabu SAITOProfessor (Graduate School of Engineering)

Research Theme

Deexcitation process of molecular ions excited by photon or electron impact using an ion storage ring or ion beam trap.

Development of a desktop sized electrostatic ion beam trap and its application for precise measurement of the lifetime of metastable states of ions.


Fundamentals of Atomic Collisions, Applied Electromagnetism, Introduction to Quantum Science

Contact Information

Katsura Campus, C3 building, Room d1S04
TEL: 75-383-3904
FAX: 75-383-3904
E-mail: saito@* (Add "nucleng.kyoto-u.ac.jp" after @)

Hidetsugu TSUCHIDA

Hidetsugu TSUCHIDAAssociate Professor (Graduate School of Engineering)

Research Theme

  • Experimental studies of radiation reactions in collision processes with materials (atoms, molecules, clusters, liquids, solids, etc.) using a particle accelerator.
  • Real-time observations of irradiation-induced nonequilibrium reactions, and investigations of its physical mechanism.
  • New methods of production of fast cluster microbeams and aligned molecular beams.


Radiation Detection and Measurement, Particle Accelerator Engineering, Radiation Measurements for Medicine

Contact Information

Uji Campus, Uji Reaserch Bldg. Room 214
TEL: +81-774-38-3974
FAX: +81-774-38-3974

Katsura Campus, C3 Bldg. Room d1N05
TEL: +81-75-383-3929

E-mail: tsuchida@* (Add "nucleng.kyoto-u.ac.jp" after @)


Jiro MATSUOAssociate Professor (Graduate School of Engineering)

Research Theme

  • Development of novel surface modification process and surface analysis technology using quantum beam
  • Study of polyatomic collision effects by cluster ion impact

Contact Information

Uji Campus, Uji Research Bldg. 221
TEL: +81-774-38-3977
FAX: +81-774-38-3978
E-mail: matsuo.jiro.7s(A)kyoto-u.ac.jp
Beam Application Group


Takuya MAJIMAAssociate Professor (Graduate School of Engineering)

Research Theme

  • Radiation Physics and Chemistry
  • Atomic Collision Physics
  • Atomic, Molecular and Cluster Physics

Contact Information

Uji Campus, Uji Research Bldg. 212
TEL: +81-774-38-3972
FAX: +81-774-38-3972

Katsura Campus, C3 Bldg. d1N06
TEL: +81-75-383-3931

E-mail: majima(o)nucelng.kyoto-u.ac.jp

Toshio SEKI

Toshio SEKIJunior Associate Professor (Graduate School of Engineering)

Research Theme

  • Development of novel surface modification process and surface analysis technology using quantum beam
  • Study of polyatomic collision effects by cluster ion impact

Contact Information

Uji Campus, Uji Research Bldg. 221
TEL: +81-774-38-3977
FAX: +81-774-38-3978
E-mail: seki.toshio.7r@* (Add "kyoto-u.ac.jp" after @)
Beam Application Group
personal page

Makoto IMAI

Makoto IMAIAssistant Professor (Graduate School of Engineering)

Research Theme

Contact Information

TEL: +81-75-383-3905
E-mail: imai@* (Add "nucleng.kyoto-u.ac.jp" after @)

Research Topics

Ion-solid interaction-based functioning and its application to quantum technology

Accelerator technology has been one of driving forces to develop the quantum science. That is, particle beams of ions, electrons and photons provided by accelerators have been quite versatile tools to understand detailed quantum interactions and structures of solids and particles, because of continuously sophisticated specifications and functions of particle beams, which become today highly reliable popular techniques in various fields.

For examples, a huge amount of detailed information on ion scattering, its reaction, photon and electron emissions was originally dedicated to understand the structure of atoms and nuclei. These highly developed techniques are now used, as analytical tools of Rutherford backscattering spectroscopy and particle-induced X-ray emission, in fields of materials, space, environmental and bio sciences.

This research project is to understand fundamental processes and mechanisms of ion-solid interaction, and to develop high sensitive analytical tools applied to nanometer-scale structures.


Figure 1:Quantum phenomena and its application to quantum technology

Synthesis of self-assembled quantum dots by ion implantation and creation of quantum systems

Quantum systems, systems manufactured based on science and technology relating to the quantum phenomena, are today very popular all over the world.

Nano science and technology, one of the key sciences and technologies in our century, will provide great quantum systems including quantum computers. These kinds of quantum systems will keep a great contribution to the sustainable development of human society.

This research project is focused on the application of ion implantation technologies to the synthesis of silicon-based self-assembled quantum dots and to fabricate nature-friendly quantum systems.


Figure 2:Synthesis of quantum dots: TEM image of single crystals, Apparatus and light emission

Material and space research using high energy cluster ion beam and hypervelocity fine particles

Cluster and fine particle ions can be bombarded a very small area of a solid surface by many atoms simultaneously and release large kinetic energy in a very short time. This phenomenon causes nonlinear effects or synergetic effects, which are not normally caused by a single atom collision with matter. We investigate such nonlinear effects on high energy cluster ion beam impact with metals, semi-conductors, ceramics and polymers. Sometimes you can find crater-like holes on a surface of solid in these impact. We need to clarify mechanism of production of craters and we can modify and produce materials by controlling these nonlinear effects.In space you can easily find these cluster, organic molecules and fine particles (dust particle).

In these years impacts of space debris on space crafts become severe problem. So we simulate the space debris or dust impacts on various targets by using accelerated fine particles and also we are developing dust detector/analyzer on board space crafts.

Atomic Collision Processes related to Nuclear Fusion Energy Research

When ion-beams collide with targets like atoms, molecules, solids, surfaces and so on, there occurs many kinds of stochastic and competitive processes, accompanying internal changes of both collision partners. These processes bring us unique and exclusive knowledge of collision dynamics, like formation of intermediate states and further structural changes, which are not available from static research. Basic data for investigating entire processes in nano-scales, concerning atoms and molecules, can be obtained through experimental study. We are now devote ourselves to the collision processes,essential to continuous plasma-burning in the future fusion devices,such as fuel feeding, ash or impurity extraction, plasma diagnostics and so on.