IPAC2016 - List of Authors (Uesaka, M.)

Paper	Title	Page
TUPMY017	Laser Driven Dielectric Accelerator in the Non-relativistic Energy Region	1585
	K. Koyama, M. Uesaka The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan S. Kurimura NIMS, Ibaraki, Japan H. Okamoto, S. Otsuki The University of Tokyo, Tokyo, Japan M. Yoshida KEK, Ibaraki, Japan
	Laser-driven dielectric accelerator (LDA) is suitable for delivering a submicron-size ultra-short electron beam, which is useful for studying basic processes of the radiation effect in a biological cell. Both the oblique incidence and the normal incidence configurations of LDA were studied. The oblique incidence configuration of LDA relaxes the synchronization condition as v_e=¥pm c L_G/¥left(¥λ+ L_G n ¥sin ¥theta ¥right) and is somewhat suitable for accelerating the non-relativistic electrons. The required energy to accelerate electrons in the oblique incidence configuration is smaller than that in the normal incidence configuration by a factor of ¥cos ¥theta, where ¥theta is the incidence angle of the laser beam. Two gratings each were made of different material structure of silica ({¥rm SiO₂}) were fabricated by the electron beam lithography. When a crystal silica was adopted, many large humps of several hundred nm size were observed in grooves of the grating. On the other hand, a glass silica had smoother grooves.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMY017
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOY007	Development of a Compact X-Band Electron Linac for Production of Mo-99/Tc-99m	1917
SUPSS110	use link to see paper's listing under its alternate paper code
	J. Jang The University of Tokyo, Tokyo, Japan M. Uesaka The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan M. Yamamoto Accuthera Inc., Kawasaki, Kanagawa, Japan
	In response to the need of alternatives to the exhausted research reactors supplying Mo-99/Tc-99m, we are developing a compact X-band electron linear accelerator (linac). As an initial step, beam dynamics simulations were performed and electron beams of 35 MeV and 9.1 kW were obtained. We expect that sixteen linacs having these beam parameters can cover the demand of Tc-99m radiopharmaceuticals in Japan. On the other hand, we found that the combination of X-band RF and high beam power can give rise to instability of beam loading. We will therefore adjust and optimize the beam power while keeping Mo-99 production efficiency as high as possible.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOY007
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOY047	Development of a Non-destructive Inspection System for Industrial and Societal Infrastructures with 950 keV/3.95 MeV Portable X-band Linac-based X-ray	2011
	R. Yano The University of Tokyo, Tokyo, Japan J. Kusano Accuthera Inc., Kawasaki, Kanagawa, Japan M. Uesaka The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan
	Advanced maintenance for aging industrial and societal infrastructures such as chemical plant and bridge are strongly needed recently. For the purpose, we are developing, applying and upgrading the 950 keV/3.95 MeV X-band linac X-ray sources for the on-site inspection. Less than 1 MeV accelerators are available for on-site inspection and less than 3.95 MeV accelerators are allowable for only bridge on-site inspection. These systems can visualize in seconds inner states of infrastructures, such as crack of concrete, iron-reinforced rod/wire and other imperfections. By using the 950 keV system, we conducted the first inspection of the real bridge and evaluated degradation of pre-stressed concrete wires. We also demonstrated first on-site use of the 3.95 MeV system in Japan in 2015. We are also performing structural analysis to evaluate the degradation of strength. For more precise evaluation, we are going to carry out a partial angle CT to reconstruct a two-dimensional inner structure. We are going to present the results and strategy of degradation evaluation of the industrial and societal infrastructures by the 950 keV / 3.95 MeV X-ray sources.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOY047
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMY041	Development of Mobile Neutron Sources Driven by X-Band Electron Linacs for Infrastructure Maintenance and Nuclear Security	2648
	Y. Seki, J.M. Bereder, M. Uesaka The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan
	We are developing a compact neutron source with a 3.95 MeV X-band (9.3 GHz) electron linac based X-ray source. The X-ray source, which included a tungsten target for bremsstrahlung, was originally fabricated for on-site nondestructive inspections for infrastructures such as bridges, expressways and tunnels. Attachment of a photo-neutron target to this X-ray source allows a new mobile neutron source. Main applications of this neutron source are on-site moisture detection in infrastructures, and nuclear materials measurement in fuel debris for decommissioning Fukushima nuclear power plants. Our approach also realizes a mobile X-ray/neutron hybrid source system in the future. The beryllium was employed as target material since it had especially small threshold energy for the photo neutron production. We have developed a 60-cm-cube target station by combining a beryllium block, a graphite reflector, a polyethylene moderator, a boric acid resin layer (neutron shied), and a lead layer (gamma-ray shield). This presentation will report a pilot experiment of neutron generation and discuss the results compared to a Monte Carlo simulation.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMY041
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOW056	Fiber Laser Development for Dielectric Laser-driven Accelerator and Electron Beam Source	4070
SUPSS024	use link to see paper's listing under its alternate paper code
	H. Okamoto, S. Otsuki The University of Tokyo, Tokyo, Japan K. Koyama, M. Uesaka The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan D. Satoh, T. Shibuya TIT, Tokyo, Japan M. Yoshida KEK, Ibaraki, Japan
	Our group is aiming for developing a table-top electronμbeam source, whose beam size is micro-meter order so that we can irradiate just the nuclei of cells (1μm) and observe the behavior in real time. This beam source will be realized by dielectric laser-driven accelerators(DLAs), which is expected to produce acceleration gradients of ~GV/m. To drive these accelerators, ultra-short pulse laser has to be incident to the structure. We chose Ytterbium (Yb) fiber laser for generating and amplifying ultra-short laser pulse, which has high quantum efficiency and can easily pumped by LD, and is proper to produce ultra-short pulses because of its wide-band oscillation. We succeeded in getting ultra-short pulse (central wavelength: {1030} nm, average output: 10 W, pulse duration: ~10 ps, reputation rate: 84 MHz) from Yb fiber laser system. Also in order to make electron bunch by photo cathode, we then converted the obtained IR laser to UV of 258 nm (4ω) using BBO and LBO crystals. We are planning to amplify the pulses by Yb:YAG in future, which has its amplification band in {1030} nm. K. Koyama el al., "Design Of Photonic Crystal Accelerator For Radiation Biology," IPAC'12 Proceedings (2014)
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW056
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Laser Driven Dielectric Accelerator in the Non-relativistic Energy Region

1585

K. Koyama, M. Uesaka
The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan
S. Kurimura
NIMS, Ibaraki, Japan
H. Okamoto, S. Otsuki
The University of Tokyo, Tokyo, Japan
M. Yoshida
KEK, Ibaraki, Japan

Laser-driven dielectric accelerator (LDA) is suitable for delivering a submicron-size ultra-short electron beam, which is useful for studying basic processes of the radiation effect in a biological cell. Both the oblique incidence and the normal incidence configurations of LDA were studied. The oblique incidence configuration of LDA relaxes the synchronization condition as v_e=¥pm c L_G/¥left(¥λ+ L_G n ¥sin ¥theta ¥right) and is somewhat suitable for accelerating the non-relativistic electrons. The required energy to accelerate electrons in the oblique incidence configuration is smaller than that in the normal incidence configuration by a factor of ¥cos ¥theta, where ¥theta is the incidence angle of the laser beam. Two gratings each were made of different material structure of silica ({¥rm SiO₂}) were fabricated by the electron beam lithography. When a crystal silica was adopted, many large humps of several hundred nm size were observed in grooves of the grating. On the other hand, a glass silica had smoother grooves.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMY017

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOY007

Development of a Compact X-Band Electron Linac for Production of Mo-99/Tc-99m

1917

SUPSS110

use link to see paper's listing under its alternate paper code

J. Jang
The University of Tokyo, Tokyo, Japan
M. Uesaka
The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan
M. Yamamoto
Accuthera Inc., Kawasaki, Kanagawa, Japan

In response to the need of alternatives to the exhausted research reactors supplying Mo-99/Tc-99m, we are developing a compact X-band electron linear accelerator (linac). As an initial step, beam dynamics simulations were performed and electron beams of 35 MeV and 9.1 kW were obtained. We expect that sixteen linacs having these beam parameters can cover the demand of Tc-99m radiopharmaceuticals in Japan. On the other hand, we found that the combination of X-band RF and high beam power can give rise to instability of beam loading. We will therefore adjust and optimize the beam power while keeping Mo-99 production efficiency as high as possible.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOY007

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOY047

Development of a Non-destructive Inspection System for Industrial and Societal Infrastructures with 950 keV/3.95 MeV Portable X-band Linac-based X-ray

2011

R. Yano
The University of Tokyo, Tokyo, Japan
J. Kusano
Accuthera Inc., Kawasaki, Kanagawa, Japan
M. Uesaka
The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan

Advanced maintenance for aging industrial and societal infrastructures such as chemical plant and bridge are strongly needed recently. For the purpose, we are developing, applying and upgrading the 950 keV/3.95 MeV X-band linac X-ray sources for the on-site inspection. Less than 1 MeV accelerators are available for on-site inspection and less than 3.95 MeV accelerators are allowable for only bridge on-site inspection. These systems can visualize in seconds inner states of infrastructures, such as crack of concrete, iron-reinforced rod/wire and other imperfections. By using the 950 keV system, we conducted the first inspection of the real bridge and evaluated degradation of pre-stressed concrete wires. We also demonstrated first on-site use of the 3.95 MeV system in Japan in 2015. We are also performing structural analysis to evaluate the degradation of strength. For more precise evaluation, we are going to carry out a partial angle CT to reconstruct a two-dimensional inner structure. We are going to present the results and strategy of degradation evaluation of the industrial and societal infrastructures by the 950 keV / 3.95 MeV X-ray sources.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOY047

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMY041

Development of Mobile Neutron Sources Driven by X-Band Electron Linacs for Infrastructure Maintenance and Nuclear Security

2648

Y. Seki, J.M. Bereder, M. Uesaka
The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan

We are developing a compact neutron source with a 3.95 MeV X-band (9.3 GHz) electron linac based X-ray source. The X-ray source, which included a tungsten target for bremsstrahlung, was originally fabricated for on-site nondestructive inspections for infrastructures such as bridges, expressways and tunnels. Attachment of a photo-neutron target to this X-ray source allows a new mobile neutron source. Main applications of this neutron source are on-site moisture detection in infrastructures, and nuclear materials measurement in fuel debris for decommissioning Fukushima nuclear power plants. Our approach also realizes a mobile X-ray/neutron hybrid source system in the future. The beryllium was employed as target material since it had especially small threshold energy for the photo neutron production. We have developed a 60-cm-cube target station by combining a beryllium block, a graphite reflector, a polyethylene moderator, a boric acid resin layer (neutron shied), and a lead layer (gamma-ray shield). This presentation will report a pilot experiment of neutron generation and discuss the results compared to a Monte Carlo simulation.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMY041

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOW056

Fiber Laser Development for Dielectric Laser-driven Accelerator and Electron Beam Source

4070

SUPSS024

use link to see paper's listing under its alternate paper code

H. Okamoto, S. Otsuki
The University of Tokyo, Tokyo, Japan
K. Koyama, M. Uesaka
The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan
D. Satoh, T. Shibuya
TIT, Tokyo, Japan
M. Yoshida
KEK, Ibaraki, Japan

Our group is aiming for developing a table-top electronμbeam source, whose beam size is micro-meter order so that we can irradiate just the nuclei of cells (1μm) and observe the behavior in real time. This beam source will be realized by dielectric laser-driven accelerators(DLAs), which is expected to produce acceleration gradients of ~GV/m. To drive these accelerators, ultra-short pulse laser has to be incident to the structure*. We chose Ytterbium (Yb) fiber laser for generating and amplifying ultra-short laser pulse, which has high quantum efficiency and can easily pumped by LD, and is proper to produce ultra-short pulses because of its wide-band oscillation. We succeeded in getting ultra-short pulse (central wavelength: {1030} nm, average output: 10 W, pulse duration: ~10 ps, reputation rate: 84 MHz) from Yb fiber laser system. Also in order to make electron bunch by photo cathode, we then converted the obtained IR laser to UV of 258 nm (4ω) using BBO and LBO crystals. We are planning to amplify the pulses by Yb:YAG in future, which has its amplification band in {1030} nm.
* K. Koyama el al., "Design Of Photonic Crystal Accelerator For Radiation Biology," IPAC'12 Proceedings (2014)

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW056

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)