Prof. Y. Yoshida

Assoc. Prof. J. Yang

Assis. Prof. T. Kondoh

The department is going to generate an ultralow-emittance, femtosecond/attosecond-bunch electron beam using a laser photocathode linear accelerator (linac) for new applications. A femtosecond/attosecond pulse radiolysis facility based on the ultrashort electron bunch and the ultrashort laser light is constructed for revealing the hidden chemical kinetics and radiation primary processes in materials for the nanotechnology and next nanofabrication. The femtosecond time-resolved MeV electron diffraction and electron microscope are developed for studying the ultrafast structural dynamics.

[Research Topics] Generation and measurement of the femto/attosecond electron beam. Development of the femtosecond/attosecond pulse radiolysis. Studies of the radiation induced ultrafast reactions and the nanofabrication processes. Development of the femtosecond time-resolved and MeV electron microscope. Generation of the multimode THz radiation Study of nano-beams for radiation therapy.

Secretary A. Chiyo

Specially Appointed Researcher A. Ogawa

Specially Appointed Researcher S.Gonda

Specially Appointed Researcher H.Kobayashi

Asis Prof. K Kan

Specially Appointed Researcher K.Norizawa

kumikoタイプライターテキスト

kumikoタイプライターテキストas of April 2013

Assoc. Prof. R. Kato

The group of the Department of Accelerator Science conducts research mainly with the L-band electron linac, though it also contributes to operation and maintenance of the linac and the 60Co -ray irradiation facility. Its research themes cover production of light beams as secondary beams produced with electron beams accelerated with the L-band linac, brightness enhancement and stabilization of the electron beams, which is necessary for production of the light beams, and, by further going upstream, improvement of the linac for higher performance. To put it concretely, we conduct researches on production of highly brilliant electron beams with the linac and related beam dynamics, development of a far-infrared, or THz free-electron laser (FEL) for user experiments, basic study on SASE (Self-Amplified Spontaneous Emission) in the infrared region, which is a promising candidate for realizing X-ray lasers, and development of a high performance wiggler with the strong focusing force, named the edge-focusing (EF) wiggler.

[Research Topics] Improvement of the L-band linac for higher operational stability and reproducibility, and researches on production

of a highly brilliant electron beam with a linear accelerator and related beam dynamics. Development of a far-infrared FEL for users experiment, and study on FEL for extension of the wavelength

region and higher performance. Experimental study of SASE (Self-Amplified Spontaneous Emission), which is a single pass, high gain FEL

oscillator, amplifier, in the far- infrared region and basic studies in its related fields. Development of a high performance wiggler for SASE.

40 60 80 100 120 140 160 180 200

wavelength [m]

10-1

100

101

102

103

104

inte

nsity

[J/

s/m

]

fundamental

2nd harmonic

3rd harmonic

ISIR-FEL system First model of the Edge-Focusing

Wavelength spectra of SASE

Prof. G. Isoyama

Assis.Prof.K.Kawase

Assis. Prof. A.Irizawa

kumikoタイプライターテキストas of Jun 2012

“Beam-induced molecular chemistry” based on photo and radiation-induced chemistry of organic compounds has been

investigated from both basic and functional points of view. The recent research topics are developments of new synthetic

chemistry, multi-beam induced photochemistry, and biomolecules conjugated with photofunctional molecules.

【Research Topics】 Formation and reactivities of reactive intermediates such as excited states and radical in photochemistry and

radiation chemistry. Multi-beam chemistry with multi-step irradiation of two-color two-laser or combined irradiation of electron pulse

and laser. Development of new TiO2 photocatalyst, mechanism of charge transfer on the photofunctional surfaces during

TiO2 photocatalytic reactions using single-molecule fluorescence spectroscopy. DNA and Protein molecular chemistry such as charge transfer in DNA, DAN oxidative damage, DNA and protein

dynamics, and local environment of DNA. Charge transfer and delocalization in supramolecules using -radiolysis, pulse radiolysis, and laser photolysis. Reactive intermediates studied by pulse radiolysis-transient Raman and infrared absorption spectroscopies.

New reactions originated from excited states of intermediates DNA strand cleavage promoted by photofunctional molecule

Development of new TiO2 photocatalyst and reaction mechanism of photocatalytic reaction by single molecule fluorescence imaging technique

Prof. T. Majima Assoc. Prof. M. Fujitsuka Assoc. Prof. K. Kawai

Assis. Prof. T. Tachikawa

Specially-appointed Assis. Prof. J. K. Choi

Conformational dynamics of biomolecules: Protein folding etc.

kumikoタイプライターテキストas of April 2013

The industrial application of quantum beam will rapidly expand in the field such as high-volume production of

semiconductor devices. Cancer therapy using ionizing radiation has also attracted much attention. In Department of Beam

Materials Science, the radiation-induced chemical reaction and reaction field have been investigated using state-of-the-art

quantum beam (electron, extreme ultraviolet radiation, laser, synchrotron radiation, X-ray, g-ray, ion beam). We have

studied the chemical reaction system from the energy deposition on materials to the expression of material function. On the

basis of these studies, we have designed a noble chemical reaction system.

[ResearchTopics] Challenge toward nano chemistry in high-volume production of.

Radiation chemistry in the energy range of extreme ultraviolet.

Design of next generation resist materials - electron, hole, and energy transfer in condensed matter

Study of radiation-induced reaction of organic and bio-materials using pulse radiolysis.

Mechanism of genetic damage caused by ionizing-radiation

Radiation chemistry study on high temperature/ pressure and supercritical solutions

Study on Nano-materials using quantum beam.

0

Prof, T, Kozawa

Assis, Prof, K, Kobayashi Assis, Prof, H, Yamamoto

Chemical reaction in nano-space

Pulse radiolysis

20

30

40

50

60

70

40 50 60 70 80 90 100

C 37 (mM)

Aci

d yi

eld

(mM

)

I+

CF3SO3-

t-But-Bu

S+ PF6-I+

C4F9SO3-

O2S-NO2S CF2

CF2CF2

I+ t-But-Bu

t-Bu I+ t-Bu

-CSO2CF3

SO2CF3SO2CF3

S+ C4F9SO3-

S+O2S-NO2S CF2

CF2CF2

S+ CF3SO3-

S+SbF6-

S+SO2CF3

-C SO2CF3SO2CF3

N

O

O

OSO2CF3N

O

O

OSO2CF3

N O SO

O

O

O

I+

CF3SO3-

*●TPS AX, ●DPI AX, ●Non ionic AX

0

0.1

0.2

0.3

0.4

0.5

-200 0 200 400 600 800 1000

Time (ps)

Opt

ical

den

sity

0 mM

10 mM30 mM

100 mM

0

0.1

0.2

0.3

0.4

0.5

0 50 100 150 200

PI-tf (mM)

Initi

al y

ield

(O. D

.)

IY/e

[IY] : Initial yield of THF

C37

f = exp (-[S] / C37)

Reaction of acid generator in THF solution

Dependence of initial yield of solvated electron on acid generator concentration

Relationship between C37 and acid yield

①Reaction with solvated electron②Reaction with thermalized electron

①②

（Liquid）

（Solid

）

Study of radiation-induced reaction of organic using pulse radiolysis

Challenge toward nano chemistry in high-volume production of semiconductor devices

Imaging Radiation chemistry study on high temperature/pressure and supercritical solutions

Mechanism of genetic damage caused by ionizing-radiation

Study on Nano-materials using

quantum beam.

Assoc. Prof, Y, Muroya

kumikoタイプライターテキストas of April 2013

There are two full-time members and three support staffs, a technical staff and a part-time technical staff in this facility.

We have been developing intense slow positron beam using electron linac as a new diagnostic technique of nano scale

spaces in materials. In addition to the administrative work and maintenance of the facilities. We also study the annihilation

process of positron in polymer electrolyte membrane to elucidate the degradation process of it. We have also been studying

new reactive intermediates in organic materials and evaluating materials using pulse radiolysis technique based on L-band

linac and laser.

[Research Topics]

1. Improvement of the electron linac and production of an intense slow positron beam

2. Development of high brightness positron beam and its application to positron diffraction experiment

3. Characterization of polymer electrolyte membrane for fuel cell using positron annihilation spectroscopy

4. Development and evaluation of environmental materials by pulse radiolysis

5. Formation and reactivities of quantum beam induced new organic reactive intermediates

Positron Annihilation Spectroscopy

System Based on RI Positron Source

Environmental materials organic compounds

electron beam

Slow Positron Beamline

Beam port for Surface analisis

Beam port for the analysis of nano scale holes

Positron Lifetime Spectroscopy Age-Momentum Correlation (AMOC) Angular Correlation Laser irradiation, etc

Thermalization & Reemission

Energy：100MeV Current: 400mA(Peak) Repetition:30Hz Pulse Width: 2 μs

Reflection of High

Energy Positron Diffraction

Bremsstrahlung Pair creation

Assoc, Prof, Y, Honda

Assis, Prof, S, Tojo

Generation of Slow Positron Beam

Nano-second pulse radiolysis by using electron beam

Pair creation

Specially Appointed

Researcher. A. Tokuchi

Change of o-Ps lifetime with relative humidity for Nafion-117.

Guiding coilsHelmholtz coils

S-band linacSlow positron production room

Measurement room

kumikoタイプライターテキストas of July 2013