Updated on 2025/02/10

写真a

 
ASAKAWA,Makoto
 
Organization
Faculty of Engineering Science Professor
Title
Professor
External link

Degree

  • -

Research Interests

  • プラズマ物理

  • 加速器物理

  • accelerator physics

  • Plasma Physics

Research Areas

  • Natural Science / Mathematical physics and fundamental theory of condensed matter physics

Education

  • Osaka University   Graduate School, Division of Engineering

    - 1995

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  • Osaka University

    - 1995

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    Country: Japan

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  • Kansai University   Faculty of Engineering

    - 1990

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    Country: Japan

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  • Kansai University   Faculty of Engineering

    - 1990

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Research History

  • 関西大学システム理工学部物理・応用物理学科

    2012

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  • Kansai University Faculty of Engineering Science, Department of Pure and Applied Physics   Associate Professor

    2005 - 2011

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  • 大阪大学大学院工学研究科電子工学専攻

    2000 - 2005

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  • 京都大学大学院理学研究科物理・宇宙物理学専攻

    1995 - 2000

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Professional Memberships

Papers

  • Terahertz time-domain spectroscopy of tooth components for caries diagnosis

    Haruto Kobashi, Wangxuan Zhao, Verdad C. Agulto, Kosaku Kato, Toshiyuki Iwamoto, Koki Miura, Takahiko Shiraogawa, Yoshihiro Nishitani, Naoya Kurahashi, Yoshinori Sakanoue, Sadami Tsutsumi, Makoto R. Asakawa, Makoto Nakajima

    International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz   2024

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    Publishing type:Research paper (international conference proceedings)  

    To confirm the possibility of identification between dentin and decalcified dentin in the terahertz (THz) region, transmission characteristics of these tooth components were measured by terahertz time-domain spectroscopy (THz-TDS). The refractive index and absorption coefficient of decalcified dentin are found to be lower compared to those of dentin. These results suggest the potential application of THz waves in caries diagnosis.

    DOI: 10.1109/IRMMW-THz60956.2024.10697660

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  • Visualization of Particle Packing Structure of AP/HTPB Composite Propellant by 3D X-ray CT Image Analysis Reviewed

    Akihiro Terachi, Taisei Nitta, Haruaki Komori, Akihiro Iwasaki, Makoto Asakawa, Soichiro Yamaguchi

    AIAA SCITECH 2023 Forum   2023.1

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    Publishing type:Research paper (international conference proceedings)   Publisher:American Institute of Aeronautics and Astronautics  

    DOI: 10.2514/6.2023-1690

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  • Ultrafast visualization of an electric field under the Lorentz transformation Reviewed

    Masato Ota, Koichi Kan, Soichiro Komada, Youwei Wang, Verdad C. Agulto, Valynn Katrine Mag-usara, Yasunobu Arikawa, Makoto R. Asakawa, Youichi Sakawa, Tatsunosuke Matsui, Makoto Nakajima

    Nature Physics   18 ( 12 )   1436 - 1440   2022.10

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    Publishing type:Research paper (scientific journal)   Publisher:Springer Science and Business Media LLC  

    Abstract

    In special relativity, four-vectors, such as space–time, energy–momentum and electromagnetic potential vectors, follow the Lorentz transformation. The transformations of space–time and energy–momentum vectors have been tested by time dilation and rest mass energy experiments, respectively. However, the Lorentz transformation of electromagnetic potentials has never been directly demonstrated in experiments due to the limitations of the diagnostics. Here we show the spatiotemporal electric-field profiles around a highly energetic electron beam with a subpicosecond temporal resolution obtained by a terahertz technique based on electro-optic sampling. We observe the Coulomb field contraction in the propagation direction of the beam under the Lorentz transformation. After passing the beam through a metallic plate, we investigate the birth of the Coulomb field around it and follow the spatiotemporal evolution of the spherical wavefront, which is derived by the Liénard–Wiechert potentials. The measured electric-field profile in the far propagation distance is experimentally confirmed to coincide with the calculation of the Liénard–Wiechert potentials and the Lorentz transformation. Our ultrafast measurement of a spatiotemporal relativistic electric field provides both additional experimental evidence of special relativity and a platform for detailed experimental research of energetic charged particle beams and electromagnetic radiation physics.

    DOI: 10.1038/s41567-022-01767-w

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    Other Link: https://www.nature.com/articles/s41567-022-01767-w

  • Generation of a Sub-Picosecond Sheet Electron Beam Using a 100 fs Laser Reviewed

    M. Asakawa, S. Yamaguchi, Y. Karaki, H. Matsubara, Y. Miyajima, R. Michishita, T. Shirai, R. Horii, S. Yoshimatsu

    Proceedings of 40th International Free Electron Laser Conference Trieste,Italy | August 22-26, 2022   175 - 178   2022.9

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    DOI: 10.18429/JACoW-FEL2022-TUP09

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  • Ablation phenomena by intense terahertz vortex beam Reviewed

    You Wei Wang, Sadashi Segawa, Tomoki Shimizu, Verdad C. Agulto, Valynn Katrine Mag-usara, Kosaku Kato, Katsuhiko Miyamoto, Takashige Omatsu, Kotaro Makino, Junji Tominaga, Goro Isoyama, Makoto Asakawa, Makoto Nakajima

    Applied Physics A   128 ( 9 )   2022.8

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    Publishing type:Research paper (scientific journal)   Publisher:Springer Science and Business Media LLC  

    DOI: 10.1007/s00339-022-05970-7

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    Other Link: https://link.springer.com/article/10.1007/s00339-022-05970-7/fulltext.html

  • Contribution of Microwave to the Formation of Octacalcium Phosphate Intercalating Succinate Ions Reviewed

    Yoshiaki Tsunawaki, Kiyoko Sakamoto, Soichiro Yamaguchi, Makoto Asakawa, Yuusuke Yamaguchi, Seitaro Mitsudo, Toshitaka Idehara

    Journal of Infrared, Millimeter, and Terahertz Waves   42 ( 4 )   409 - 415   2021.2

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    Publishing type:Research paper (scientific journal)   Publisher:Springer Science and Business Media LLC  

    DOI: 10.1007/s10762-021-00774-x

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    Other Link: https://link.springer.com/article/10.1007/s10762-021-00774-x/fulltext.html

  • Dynamic Viscoelasticity Analysis of AP/HTPB Composite Propellant Slurry with Focusing on Gap Parameter between AP Particles Reviewed

    Kansei TERASHIMA, Akihiro IWASAKI, Makoto R. ASAKAWA, Hiroto HABU, Soichiro YAMAGUCHI

    TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN   19 ( 2 )   266 - 269   2021

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    Publishing type:Research paper (scientific journal)   Publisher:Japan Society for Aeronautical and Space Sciences  

    DOI: 10.2322/tastj.19.266

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  • Terahertz Radiation from Combined Metallic Slit Arrays Reviewed

    Dazhi Li, Makoto Nakajima, Masahiko Tani, Jinfeng Yang, Hideaki Kitahara, Masaki Hashida, Makoto Asakawa, Wenxin Liu, Yanyu Wei, Ziqiang Yang

    Scientific Reports   9 ( 1 )   2019.5

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    Publishing type:Research paper (scientific journal)   Publisher:Springer Science and Business Media LLC  

    Abstract

    We report an approach to efficiently generate terahertz radiation from a combined periodic structure. The proposed configuration is composed of two metallic slit arrays deliberately designed with different periodic length, slit width and depth. We found that the combination of the two slit arrays could provide special electromagnetic modes, which exhibit nonradiative property above the surface of one slit array and radiative property inside the other one. An electron beam holding proper energy could resonate with those modes to generate strong and directional electromagnetic radiations in the terahertz regime, indicating that the approach has the potential in developing high-performance terahertz radiation sources.

    DOI: 10.1038/s41598-019-43072-2

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    Other Link: https://www.nature.com/articles/s41598-019-43072-2

  • Smith-Purcell radiation emitted by pico-second electron bunches from a 30 keV photo-electron gun

    M. R. Asakawa, S. Yamaguchi

    Proceedings of the 39th International Free-Electron Laser Conference, FEL 2019   66 - 68   2019

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    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:JACoW Publishing  

    A compact radiation source based on the combination of Smith-Purcell radiation and the coherent radiation emitted by the short electron beam is being developed. A photo-electron gun driven by 100 fs laser generated short pulse electron beam with a charge of 300 pC at the space-charge limitation operation. To evaluate the pulsewidth of the photo-electron beam, we developed a method based on the envelope equation. In this method, the pulsewidth was evaluated by the comparison of the measured beam radius and calculated beam radius. The result showed that while the pulsewidth increased with the beam charge, it remained shorter than 3.3 ps even at the maximum charge operation. With this electron beam, experiments to generate Smith-Purcell radiation was performed. Nonlinear dependence of the radiation energy on the charge was observed and this result indicated the occurrence of the collective radiation process.

    DOI: 10.18429/JACoW-FEL2019-TUP012

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  • Development of Terahertz Radiation Source With Slit-Array Structure Reviewed

    Dazhi Li, T. N. K. Phan, K. Kato, M. Nakajima, M. R. Asakawa, M. Hashida, M. Tani, W. Liu, Y.Wei

    Scientific Reports   9   6804-1 - 6804-7   2018.9

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    Language:English   Publishing type:Research paper (scientific journal)  

    © 2018 IEEE. We have proposed a slit-array configuration demonstrating higher efficiency in terahertz radiation. Based on the radiation mechanism, we planned to develop terahertz emitter and coherent radiation source. Research on the geometrical structure, the output methods, and the radiation characteristics are being performed, and the experimental setup is under construction. In this paper, we report on the radiation physics and the consideration on effectively outputting the terahertz radiation, and introduce the recent progress in experiments.

    DOI: 10.1109/IRMMW-THz.2018.8510392

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  • Coherent radiation at the fundamental frequency by a Smith-Purcell free-electron laser with dielectric substrate Reviewed

    D. Li, Y. Wang, M. Nakajima, M. Tani, M. Hashida, M. R. Asakawa, Y. Wei, S. Miyamoto

    APPLIED PHYSICS LETTERS   110 ( 15 )   151108 - 151108   2017.4

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER INST PHYSICS  

    This letter reports an approach to realize coherent radiation at the fundamental frequency of the wave that is resonant with the electron beam in a Smith-Purcell (SP) free-electron laser (FEL). We found that a two-dimensional grating structure equipped with a dielectric substrate could provide an electromagnetic mode which shows the property of a surface wave in the vacuum region where the beam-wave interaction occurs, and operates as a radiative wave in the dielectric region. Thus, an electron beam holding medium energy resonant with the mode could radiate at the fundamental frequency, which is different from the typical Smith-Purcell free-electron laser that radiates only at harmonics of the resonant frequency. Published by AIP Publishing.

    DOI: 10.1063/1.4980046

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  • Coherent Smith-Purce radiation emitted by electron bunches produced by photo injector Reviewed

    26 ( 1 )   50 - 55   2016.8

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    Language:Japanese  

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  • Electron Guns for Free-Electron Lasers Reviewed

    Asakawa Makoto R., Yamaguchi Soichiro, Kusaba Mitsuhiro, Tsunawaki Yoshiaki

    IEEJ Transactions on Fundamentals and Materials   134 ( 1 )   22 - 25   2014

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    Language:Japanese   Publisher:The Institute of Electrical Engineers of Japan  

    Developments of two types of the electron gun are presented. One is a compact DC electron gun using Field Emitter Array (FEA) as the <i>cold</i> cathode, the other is a photoinjector which outputs sub-pico second electron beam pulse. The FEA electron gun achieved to producing a 2 mA/50 kV electron beam. The photoinjector experiments revealed an exotic space-charge effect on the ultra-shot electron beam pulse.

    DOI: 10.1541/ieejfms.134.22

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    Other Link: https://jlc.jst.go.jp/DN/JALC/10027425656?from=CiNii

  • Analysis of the double-slab type Cherenkov free-electron laser resonator

    Hiroya Yoshida, Naoya D. Munemoto, Takahiro Kimura, Takumi Sano, Soichiro Yamaguchi, Makoto R. Asakawa

    Electronics and Communications in Japan   97 ( 6 )   16 - 23   2014

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:John Wiley and Sons Inc.  

    A compact Cherenkov free-electron laser operating in the terahertz spectral range is being developed. Analysis of the double-slab type optical resonator has clarified the resonant frequency, the small signal gain, and the saturation power of the device. One-dimensional simulation code predicted a small signal gain of 6% with a 50 kV/3.6 mA electron beam. The saturation power was estimated to be 90 mW. The out-coupling structure of the resonator was designed using 3D simulation code. A transmittivity of 3.0% and a spread angle of 0.4 rad were predicted. © 2014 Wiley Periodicals, Inc.

    DOI: 10.1002/ecj.11554

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  • Analysis of the Double-slab Type Cherenkov Free-electron Laser Resonator Reviewed

    YOSHIDA Hiroya, MUNEMOTO Naoya D., KIMURA Takahiro, SANO Takumi, YAMAGUCHI Soichiro, ASAKAWA Makoto R.

    IEEJ Transactions on Fundamentals and Materials   132 ( 9 )   741 - 746   2012.9

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    Language:Japanese   Publisher:The Institute of Electrical Engineers of Japan  

    The compact Cherenkov free-electron laser operating in the terahertz spectral range is being developed. The analysis of the double-slab type optical resonator clarified the resonant frequency, the small signal gain and the saturation power of the device. One dimensional simulation code predicted a small signal gain of 6% with a 50kV/3.6mA electron beam. Saturation power was estimated to be 90mW. The out-coupling structure of the resonator was designed by using a 3D simulation code. A transmittivity 3.0% and spread angle 0.4rad was predicted.

    DOI: 10.1541/ieejfms.132.741

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    Other Link: https://jlc.jst.go.jp/DN/JALC/10008370364?from=CiNii

  • Growth rate and start current in Smith-Purcell free-electron lasers Reviewed

    D. Li, M. Hangyo, Y. Tsunawaki, Z. Yang, Y. Wei, S. Miyamoto, M. R. Asakawa, K. Imasaki

    APPLIED PHYSICS LETTERS   100 ( 19 )   191101   2012.5

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    This letter reports a theory to calculate the growth rate and start current of a Smith-Purcell free-electron laser, which is a promising radiation source in the terahertz domain. A two-dimensional model was used to investigate the interaction between a sheet electron beam and the surface wave above a lamellar grating. After deriving the growth rate from the dispersion equation, the start current was carefully estimated by considering the power flow above the grating. The agreement between the predictions of our theory and the results from the particle-in-cell simulations is acceptable. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4711803]

    DOI: 10.1063/1.4711803

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  • Super-radiant Smith-Purcell radiation from periodic line charges Reviewed

    D. Li, M. Hangyo, Y. Tsunawaki, Z. Yang, Y. Wei, S. Miyamoto, M. R. Asakawa, K. Imasaki

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   674   20 - 23   2012.5

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    Smith-Purcell radiation occurs when an electron passes close to the surface of a metallic grating. The radiation becomes coherent when the length of the electron bunch is smaller than the wavelength of the radiation. A train of periodic bunches can enhance the spectral intensity by changing the angular and spectral distribution of the radiation. This is called super-radiant Smith-Purcell radiation, and has been observed in experiments and particle-in-cell simulations. In this paper, we introduce a new method to study this effect by calculating the reflected waves of an incident evanescent wave from periodic line charges. The reflection coefficients are numerically computed, and the spectral distributions of the super-radiant radiation are demonstrated. These analytical results are in agreement with those obtained through part-in-cell simulations. (C) 2012 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.nima.2012.01.039

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  • Magnetic properties of cobalt plate compared with iron and nickel plates

    Yoshiaki Tsunawaki, Nobuhisa Ohigashi, Makoto R. Asakawa

    Japanese Journal of Applied Physics   51 ( 2 )   2012.2

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    The magnetic behavior of Co plates has been compared with those of Fe and Ni plates studied in a previous work. It was found that the factor of magnetization η b for Co plates does not show abrupt reduction with decreasing thickness, and magnetic flux density B m and magnetization P m are similar to those of Fe plates rather than Ni plates. © 2012 The Japan Society of Applied Physics.

    DOI: 10.1143/JJAP.51.028002

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  • Theoretical study of smith-purcell free-electron lasers

    D. Li, K. Imasaki, M. Hangyo, Z. Yang, Y. Wei, S. Miyamoto, M. R. Asakawa, Y. Tsunawaki

    FEL 2012 - 34th International Free Electron Laser Conference   85 - 87   2012

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    We present an analytical theory for small-signal operation of a Smith-Purcell free-electron laser with a finitely thick electron beam travelling close to the surface of a grating. The dispersion equation is derived from a self-consistent set of small-signal equations describing the dynamics of beam-wave interaction. By solving the dispersion equation carefully, we reveal that the growth rate of the field amplitude holds a finite value at the Bragg point, which is different from previous theoretical predictions. Copyright © 2012 by the respective authors.

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  • Smith-Purcell radiation from a grating of negative-index material Reviewed

    D. Li, M. Hangyo, Z. Yang, M. R. Asakawa, S. Miyamoto, Y. Tsunawaki, K. Takano, K. Imasaki

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   637 ( 1 )   135 - 137   2011.5

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    Smith-Purcell radiation from an electric line charge that moves, at constant speed, parallel to a grating made of metamaterial with negative index is analyzed. Through theoretical analysis and computations, we show that the Smith-Purcell radiation is stronger from a grating of negative-index material, than that from a positive-index material and perfect conductor. Also, we found that the radiation strongly depends on the values of permeability and permittivity. Calculations on grating with saw-like profile and rectangular profile are also carried out and demonstrated. (C) 2011 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.nima.2011.02.022

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  • Improve growth rate of Smith-Purcell free-electron laser by Bragg reflector Reviewed

    D. Li, Z. Yang, Y. Tsunawaki, M. R. Asakawa, M. Hangyo, S. Miyamoto, K. Imasaki

    APPLIED PHYSICS LETTERS   98 ( 21 )   211503-1 - ~3   2011.5

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER INST PHYSICS  

    Grating with Bragg reflectors for the Smith-Purcell free-electron laser is proposed to improve the reflection coefficient, resulting in enhancing the interaction of the surface wave with the electron beam and, consequently, relax the requirements to the electron beam. With the help of particle-in-cell simulations, it has been shown that the usage of Bragg reflectors may improve the growth rate, shorten the time for the device to reach saturation, and lower the start current for the operation of a Smith-Purcell free-electron laser. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3594243]

    DOI: 10.1063/1.3594243

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  • Smith-purcell free electron laser with Bragg reflector

    D. Li, Z. Yang, Y. Tsunawaki, M. R. Asakawa, M. Hangyo, S. Miyamoto, K. Imasaki

    FEL 2011 - 33rd International Free Electron Laser Conference   24 - 27   2011

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    Language:English   Publishing type:Research paper (international conference proceedings)  

    Grating with Bragg reflectors for the Smith-Purcell free-electron laser is proposed to improve the reflection coefficient, resulting in enhancing the interaction of the surface wave with the electron beam and, consequently, relax the requirements to the electron beam. With the help of particle-in-cell simulations, it has been shown that, the usage of Bragg reflectors may improve the growth rate, shorten the time for the device to reach saturation and lower the start current for the operation of a Smith-Purcell free-electron laser.

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  • Smith-purcell radiation with negative-index material

    D. Li, M. Hangyo, Z. Yang, Y. Tsunawaki, M. R. Asakawa, S. Miyamoto, K. Takano, K. Imasaki

    FEL 2011 - 33rd International Free Electron Laser Conference   20 - 23   2011

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    A scheme of Smith-Purcell free-electron laser with using a grating made of negative-index material is analyzed. Through theoretical analysis and computations, we show that the Smith-Purcell radiation is stronger in a specific range of radiation angle, from a grating of negative-index material, than positive-index material and perfect conductor. The dispersion relation for the surface mode of a grating of negative-index material is also worked out, which shows the possibility of realizing a Smith-Purcell free-electron laser with tens of keV electron beam.

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  • Space-charge limitation of a femtosecond photoinjector

    Hiroko Yamamoto, Hiroaki Hamabe, Shintaro Sone, Soichiro Yamaguchi, Makoto R. Asakawa

    International Journal of Optics   2011   2011

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    Experimental investigation of a compact 40-kV diode-type photoelectric DC gun driven by 100fs laser pulses revealed that the space-charge-limited current density could exceed 30kA/cm2 and that the density increased linearly with the accelerating voltage. We explained these important properties by the balance between the cathode surface field and the field produced by sheet-like electron bunches near the cathode surface. Our simple physical model agreed well with the experimental results. Copyright © 2011 Hiroko Yamamoto et al.

    DOI: 10.1155/2011/714265

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  • Output of Super-radiant Smith-Purcell radiation: A theoretical analysis Reviewed

    D. Li, Z. Shi, Z. Yang, M. R. Asakawa, G. Huo, Y. Tsunawaki, K. Imasaki

    JOURNAL OF INFRARED MILLIMETER AND TERAHERTZ WAVES   31 ( 11 )   1271 - 1277   2010.11

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:SPRINGER  

    A two-section grating system for Smith-Purcell free-electron lasers is investigated. The system is composed of two open gratings with different geometrical parameters. It is expected that the originally continuous electron beam is bunched in the first section by interaction with the evanescent wave near the grating surface, and enhanced radiation can be extracted at the second section in the form of super-radiant Smith-Purcell radiation at a designed angle. With the help of particle-in-cell simulation, the electron beam bunching and directed output of the fundamental radiation and higher order harmonics are demonstrated.

    DOI: 10.1007/s10762-010-9711-3

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  • Nonlinear analysis of Cherenkov free-electron laser with double-slab structure

    D. Li, G. Huo, K. Imasaki, M. Asakawa, Y. Tsunawaki

    Infrared Physics and Technology   53 ( 3 )   204 - 207   2010.5

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    A compact Cherenkov free-electron laser is studied for a double-slab structure with no incident field or electromagnetic feedback mechanism. The simplified model is composed of a rectangular wave-guide partially filled with two lined parallel dielectric slabs and a sheet electron beam. The interaction between the electron beam and the electromagnetic mode is described with the macro-particle approach. The coupled equations are derived and solved numerically with the parameters of an ongoing experiment, demonstrating the amplification of emitted power from spontaneous emission. © 2009 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.infrared.2009.11.007

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  • Photo-electron gun generating sub-pico second bunch

    Makoto R. Asakawa, Shintaro Sone, Hiroko Yamamoto, Ryota Sonomura, Soichiro Yamaguch, Yoshiaki Tsunawaki

    IRMMW-THz 2010 - 35th International Conference on Infrared, Millimeter, and Terahertz Waves, Conference Guide   2010

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    A 50 kV photo-electron gun was developed to construct a powerful broad-band terahertz radiation source. A magnesium photocathode was irradiated by a frequency tripled Ti:sapphire laser. Train of electron bunch of 50 pC was generated. The bunch produced the optical transition radiation at the beam dumper. © 2010 IEEE.

    DOI: 10.1109/ICIMW.2010.5613066

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  • Analysis on the gain of a compact cherenkov free-electron laser

    D. Li, K. Imasaki, M. Asakawa

    FEL 2009 - 31st International Free Electron Laser Conference   398 - 401   2009

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    Language:English   Publishing type:Research paper (international conference proceedings)  

    A compact Cherenkov free-electron laser is studied for a double-slab structure with no incident field or electromagnetic feedback mechanism. The simplified model is composed of a rectangular wave-guide partially filled with two lined parallel dielectric slabs and a sheet electron beam. The interaction between the electron beam and the electromagnetic mode is described with the macro-particle approach. The coupled equations are derived and solved numerically with the parameters of an ongoing experiment, demonstrating the amplification of emitted power from spontaneous emission.

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  • テラヘルツ波自由電子レーザー Reviewed

    綱脇惠章, 浅川 誠

    日本赤外線学会誌   17 ( 2 )   13 - 24   2008

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

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  • Development of a compact cherenkov free-electron laser operating in terahertz wave RANGE

    Nozomu Miyabe, Akira Ikeda, Makoto R. Asakawa, Mitsuhiro Kusaba, Yoshiaki Tsunawaki

    29th International Free Electron Laser Conference, FEL 2007   406 - 408   2007

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    We designed a compact Cherenkov Free-Electron Laser (CFEL) oscillator driven by 50keV electron beam. The resonator, called double-slab resonator, consists of a rectangular waveguide partially filled with two lined parallel silicon slabs, whose dielectric constant e equals to 11.6 in the terahertz frequency range. The operation frequency ranges from 40GHz to 1THz according to the thickness of the slabs. Numerical calculation predicted 100W-level output at 46GHz by electron beam with 50keV/400mA.

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  • Design of a compact Cherenkov free-electron laser Reviewed

    Makoto R. Asakawa, Nozumu Miyabe, Katsumi Nakao, Akira Ikeda, Mitsuhiro Kusaba, Yoshiaki Tsunawaki

    EIGHTH IEEE INTERNATIONAL VACUUM ELECTRONICS CONFERENCE   301 - +   2007

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    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:IEEE, ELECTRON DEVICES SOC & RELIABILITY GROUP  

    Design of a Cherenkov free-electron laser operating in millimeter wave range was carried out as a test bench for a compact terahertz radiation source. A CW output of 1.8 W is expected at the frequency of 46.4 GHz with 50 keV electron beam. The experimental apparatus consists of Spindt-cathode, double-silicon-slab resonator and super-conducting coil.

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  • Development of a compact cherenkov free-electron laser

    Makoto R. Asakawa, Nozomu Miyabe, Akira Ikeda, Yoshiaki Tsunawaki

    IRMMW-THz2007 - Conference Digest of the Joint 32nd International Conference on Infrared and Millimetre Waves, and 15th International Conference on Terahertz Electronics   638 - 639   2007

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    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:IEEE Computer Society  

    A compact Free-Electron Laser operating in the millimeter and terahertz wave range is under development. The radiation is generated via Cherenkov effect of a 50 keV electron beam passing through a waveguide loaded with silicon slabs. Comparing to the conventional undulator based FELs, our device is significantly compact because of the low energy of the electron beam. The size of the device is comparable to the THz sources fed by the solid-state fs lasers. The numerical simulation predicted an output of 2W in average with 1mA/50keV CW electron beam at a frequency of 46 GHz. A test bench using the Spindt cathode as the beam source and a superconducting magnet for the beam focusing was constructed. A preliminary lasing experiment in the millimeter wave range is now under way.

    DOI: 10.1109/icimw.2007.4516661

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  • Development of a compact cherenkov free-electron laser in terahertz spectral range

    M. R. Asakawa, K. Nakao, N. Miyabe, M. Kusaba, Y. Tsunawaki

    28th International Free Electron Laser Conference, FEL 2006   364 - 367   2006

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    A Cherenkov free-electron laser (CFEL) generating terahertz radiation is now being developed under the joint research of Osaka Sangyo university and Kansai university. The main feature of the CFEL is its compactness. Micro-beamlets from Spindt-type field emitter array are accelerated up to 50 keV and then injected into a silicon resonator with a path of 50 to 150 μ m spacing through which electrons propagate. Omitting the evacuation system and power supply, the size of CFEL section, including electron gun and resonator, is about 1 × 1 × 4 cm3. For the generation and the transport of the electron beam few μm in diameter, we investigated characteristics of the Spindt cathode, beam focusing by electrode and the magnetic field. A carbon nanotube field emitter was also tested for future application.

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  • Adjustment of adiabatic transition magnetic field of solenoid-induced helical wiggler

    Yoshiaki Tsunawaki, Nobuhisa Ohigashi, Makoto Asakawa, Kazuo Imasaki

    Proceedings of the 27th International Free Electron Laser Conference, FEL 2005   191 - 194   2005

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    A solenoid-induced helical wiggler is suitable for a compact free electron maser operated by low energy electron beam. It consists of two staggered-iron arrays installed perpendicularly to each other in a solenoid magnet. It is tried, in this work, that the adiabatic transition field is also produced by staggered-nickel plates with different thickness in five periods. It is most important how to decide each thickness of the nickel plate. After it is decided by repeated combination of the simulation and practical measurement of the magnetic field distribution, exact thickness is selected by the precise measurement of the field distribution referring to an equivalent electric circuit of the wiggler.

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  • Generation of short-pulse far-infrared light from electrons undergoing half-cyclotron rotation

    M. R. Asakawa, T. Marusaki, M. Hata, Y. Tsunawaki, K. Imasaki

    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment   528 ( 1-2 )   152 - 156   2004.8

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    A novel radiation source in the terahertz wave spectral region is being developed. The radiation is produced by electrons, which undergo a half-cyclotron rotation. Injecting the electron bunch with the energy of 150MeV into the 3m-long solenoid field, we observed that the radiation had the intense millimeter spectral component when the cyclotron resonant frequency was set to be 4THz. The numerical calculation revealed that the radiation could be regarded as a half-cycle radiation with the pulsewidth approximately equaled to that of the electron bunch. Also, the calculation pointed out the possibility to amplify such radiation in the optical resonator. © 2004 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.nima.2004.04.036

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  • Status report and. biomedical applications of the institute of FEL, Osaka University Reviewed

    K Awazu, M Asakawa, H Horiike

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   507 ( 1-2 )   547 - 551   2003.7

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    The Institute of Free-Electron Laser (iFEL) was established in April 2000 at Osaka University. The facility was constructed by the Free-Electron Laser Institute corporation (FELI) from 1992 to 1997 FELI demonstrated lasing in the spectral range from 0.28 to 20 mum. Efforts are still being made by Osaka University in order to extend the lasing range. In the operational period from April 2001 to March 2002, mid-infrared light of 5-20 mum was supplied for over 40 cooperative research programs on fields of semiconductor, bio-medical and environmental chemistry. An effort is ongoing to improve the property of the light. In this paper, the status of iFEL and some biomedical applications research are described. (C) 2003 Elsevier B.V. All rights reserved.

    DOI: 10.1016/S0168-9002(03)01864-3

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  • Magnetic field analysis of hybrid helical wiggler with multiple poles per period Reviewed

    Y Tsunawaki, N Ohigashi, M Asakawa, K Imasaki, K Mima

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   507 ( 1-2 )   166 - 169   2003.7

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    It is useful to use a high-energy electron beam and a long-period wiggler to accomplish far-infrared (FIR), free-electron laser (FEL) operation with power as high as possible. In this study, the magnetic field of a wiggler has been analyzed by computational simulation and applied to the case of an FIR-FEL driven by an electron beam of the Institute of FEL (iFEL), Osaka University, with maximum energy of 165 MeV. The wiggler is a hybrid helical consisting of permanent magnets and ferromagnetic bodies and has some poles per one period used to obtain a uniform sinusoidal magnetic field. In most simulations, the period and gap length of the wiggler were assumed to be 14 and 2 cm, respectively. A uniform field higher than 1 T was calculated for the wiggler when the number of poles per period was greater than 8. It is expected by using this kind of wiggler and an electron beam energy of 165 MeV that the power of FIR-FEL will be &gt; 100 times as high as that for a usual FEL. (C) 2003 Elsevier Science B.V. All rights reserved.

    DOI: 10.1016/S0168-9002(03)00864-7

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  • Gamma ray generation through a 1.064 mu m laser beam

    D Li, K Imasaki, M Aoki, S Miyamota, S Amano, T Mochizuki, M Asakawa, S Ishii

    INTERNATIONAL JOURNAL OF INFRARED AND MILLIMETER WAVES   24 ( 2 )   211 - 215   2003.2

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    We are exploring to process nuclear waste through nuclear transmutation method with gamma ray irradiation. The gamma ray employed for transmutation is generated in the way of Compton backscattering. Preliminary experiment is being developed on the NewSUBARU storage ring providing an electron beam with energy of 1 GeV. and 17.6MeV gamma ray will be generated through a head-on collision of the electron beam and a 1.064 mum laser light. gamma ray flux about the present experiment is predicted theoretically. A planned scheme for promoting the flux is also introduced, as well as the maximum laser power available for the storage ring is discussed.

    DOI: 10.1023/A:1021842720371

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  • Status of the Institute of Free-Electron Laser, Osaka University Reviewed

    H Horiike, N Tsubouchi, K Awazu, M Asakawa, M Heya

    Jpn. J. Appl. Phys.,Suppl.   41 ( 1 )   10 - 14   2002.2

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    Institute of Free-Electron Laser is one of the FEL supplying facilities for 2000 hours in a-year. The FEL system consists of two RF-linacs and five wigglers, and covers the wavelength range from 0.28 to 100 pm. In the operational period from April 2001 to March 2002, the mid-infrared light of 5 to 20 mum was supplied for over 40 cooperative research programs on fields of semiconductor, bio-medical and environmental chemistry An effort is still carrying on to improve the property of the light.

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  • Polarizers with non-rectangular grooves for high power millimeter waves Reviewed

    K Nagasaki, Y Itoh, K Sakamoto, T Obiki, T Maekawa, H Morioka, T Terumichi, M Asakawa, MG Shats, H Punzmann

    FUSION ENGINEERING AND DESIGN   53 ( 1月4日 )   491 - 497   2001.1

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    Polarizers with non-rectangular grooves are studied in high power millimeter wave transmission lines for electron cyclotron heating (ECH) and electron cyclotron current drive (ECCD) of fusion plasmas. The groove shape is important for determining the polarization parameters and avoiding are breakdown in the system. A low-power measurement has been carried out for several polarizers with different groove depths. The polarization characteristics experimentally measured are in good agreement with numerical results in which the actual groove shape is taken into account. The polarizers are designed and applied to different frequencies of ECH/ECCD systems. Favorable results have been obtained in high-power transmission up to 500 kW, 0.2 s. (C) 2001 Elsevier Science B.V. All rights reserved.

    DOI: 10.1016/S0920-3796(00)00525-1

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  • ECR plasma in a stuffed cusp field

    Masaki Uchida, Nobuaki Kaji, Makoto Asakawa, Hitoshi Tanaka, Takashi Maekawa, Yasushi Terumichi

    Fusion Technology   39 ( 1 T )   187 - 190   2001

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    A stuffed cusp field with a torus ECR surface is obtained by adding a toroidal stuffer field onto a simple cusp field. Results of the production of ECR plasma in this field is described. With sweeping the stuffer current, Iis start to increase when the ECR surface forms closed torus, and reaches up several times of one without the stuffer current. Only in this closed case, X-rays (&gt
    3 keV) are detected by NaI scintillator. These disappear when an obstacle is inserted inside ECR torus, suggesting that the ECR torus is of primary importance to produce and maintain energetic electrons. A peak density and temperature measured by a floating double probe reach up to ne ≅ 2 × 1012cm-3 and Te ≅ 25eV at a low Ar pressure of p ≅ 7.3 × 10-6 Torr with the microwave power of 380W.

    DOI: 10.13182/fst01-a11963438

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  • Production of Pure Electron Plasmas Using a Field Emitter Array Reviewed

    Hitoshi Tanaka, Tatsuya Sodekoda, Takashi Maekawa, Souichirou Yamaguchi, Makoto Asakawa, Yasushi Terumichi

    Jpn. J. Appl. Phys.   Vol.39, pp.602 ~ 606   2000

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  • Applications of enhanced Compton scattering in a supercavity

    M Fujita, A Moon, E Yasuda, T Asakuma, T Minamiguchi, M Asakawa, J Chen, K Imasaki, C Yamanaka, PK Roy, K Mima, S Nakai, N Nakao, T Ishida, T Watanabe, N Ohigashi, Y Tsunawaki, Y Yamazaki, M Sakuma

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   375 ( 1-3 )   ABS14 - ABS16   1996.6

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    DOI: 10.1016/0168-9002(95)01459-4

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  • 13 nm advanced SASE free electron laser with a quasi-stable optical klystron configuration Reviewed

    JZ Chen, K Imasaki, M Fujita, M Asakawa, C Yamanaka, K Mima, S Nakai

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   375 ( 1-3 )   299 - 303   1996.6

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    For soft X-ray projection lithography, we propose a 13 nm advanced SASE FEL with a quasi-stable optical klystron configuration. To shorten the wiggler length and decrease the overall size of the FEL system, we put Forward the concept of quasi-stable operation of an asymmetric optical klystron. With a similar tolerance, our advanced SASE FEL can cut down the magnetic length of a single-pass SASE FEL from 37.12 to 20.3 m at the saturation power 42.8 MW (3D cornered), at the cost of an energy-modulated e-beam bunch and an adjustable dispersion magnet system. The detail analyses are based on the Pellegrini's scaling law and the one-dimensional FEL simulation code ILT1D.

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  • Simulation of a waveguide FEL oscillator using an RF linac Reviewed

    M Goto, S Kuruma, K Mima, M Asakawa, K Imasaki, C Yamanaka

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   375 ( 1-3 )   207 - 209   1996.6

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    A one-dimensional, multi-frequency simulation code has been developed for FELs which use a waveguide to confine the radiation field. Using this simulation code, we analyzed the spontaneous emission from electron micropulses produced by an RF linac. It is found that for some parameters both high and low frequency waveguide modes are growing simultaneously and the resulting spectrum thus contains two peaks. Finally, the experimentally obtained dependence of the radiation power on cavity length detuning is analyzed.

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  • Suppression and control of leakage field in electromagnetic helical microwiggler Reviewed

    N Ohigashi, T Ishida, Y Tsunawaki, K Imasaki, M Fujita, M Asakawa, S Kuruma, C Yamanaka, S Nakai, K Mima

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   375 ( 1-3 )   469 - 473   1996.6

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    An electromagnetic helical microwiggler with three poles in one period installing permanent magnets to suppress the leakage field has been designed and manufactured. The gap field of the wiggler is adjustable by controlling the position of an iron screw set in each retainer fixing the permanent magnet blocks. In a test wiggler with a period of 7.9 mm and magnetic pole gap length of 4.6 mm, the field has been measured 2.3 kG which was more than two times larger than that of the wiggler without permanent magnets.

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  • Compact high brightness radiation sources Reviewed

    K Imasaki, M Fujita, J Chen, M Asakawa, S Nakai, C Yamanaka

    LASER INTERACTION AND RELATED PLASMA PHENOMENA   ( 369 )   820 - 829   1996

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  • RF-linac driven VUV free electron laser based on SASE Reviewed

    J Chen, M Fujita, M Asakawa, K Imasaki, C Yamanaka, K Mima, S Nakai

    LASER INTERACTION AND RELATED PLASMA PHENOMENA   ( 369 )   830 - 835   1996

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  • Development of high-brightness photon sources using enhanced compton scattering in the supercavity Reviewed

    M Fujita, T Asakuma, A Moon, T Minamiguchi, M Asakawa, J Chen, K Imasaki, C Yamanaka, PK Roy, S Nakai, N Ohigashi, Y Tsunawaki

    LASER INTERACTION AND RELATED PLASMA PHENOMENA   ( 369 )   814 - 819   1996

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  • POP EXPERIMENTS OF THE PHOTON E-BEAM INTERACTION IN THE SUPERCAVITY Reviewed

    M FUJITA, T ASAKUMA, J CHEN, K IMASAKI, C YAMANAKA, M ASAKAWA, N INOUE, K MIMA, S NAKAI, T AGARI, N NAKAO, A MOON, N OHIGASHI, T MINAMIGUCHI, Y TSUNAWAKI

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   358 ( 1-3 )   524 - 527   1995.4

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    Use of the supercavity for photon storage had been proposed to enhance the interaction between lasers and e-beams (Compton scattering). To demonstrate the feasibility of this technology, proof-of-principle (POP) experiments are in progress. A supercavity with similar to 99.99% reflectivity mirrors has been constructed to confine the LD-pumped Nd:YAG laser light. The confined photons will be used to interact with 100 kV CW electron beams. It is expected that-the interaction will be enhanced by 10(4) times, resulting in a scattered photon flux as much as 2X10(7) photons s(-1) rad(-1) at the wavelength lambda similar to 0.4 mu m.

    DOI: 10.1016/0168-9002(94)01582-1

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  • COMPACT HIGH-BRIGHTNESS RADIATION SOURCES Reviewed

    J CHEN, K IMASAKI, M FUJITA, M ASAKAWA, T ASAKUMA, S NAKAI, C YAMANAKA

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   358 ( 1-3 )   14 - 17   1995.4

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    The feasibility of compact radiation sources using photon storage technology is discussed. Compact high-brightness radiation sources with photon energies from keV to more than 10 MeV can be realized by this method. These compact radiation sources will meet the requirements of applicatioins in lithography, angiography, fission product annihilation, intense positron source and so on.

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  • HARMONICS OF THOMSON BACKSCATTERED X-RAYS Reviewed

    JH CHEN, M FUJITA, K IMASAKI, C YAMANAKA, M ASAKAWA, T YAMAMOTO, S NAKAI, T ASAKUMA

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS   33 ( 6A )   3459 - 3463   1994.6

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    A new concept of harmonic generation of Thomson backscattered X-rays by the angular alignment between the axes of the electron beam and incident laser beam has been proposed. Various properties of the backscattered X-ray harmonic radiation are examined, including the linewidth, radiation pattern on the observation plane, and the behavior of the radiation spectra at ultrahigh laser intensities. It is shown by the simulation results that when the electron beam is deliberately aligned at a suitable small angle in the polarization plane of the linearly polarized laser, both even and odd harmonics along the electron beam axis are generated, which is different from the perfectly aligned case where only odd harmonic radiations peak on the electron-laser axis. Moreover the high harmonics on the angularly aligned electron-laser configuration may have several times higher intensities compared with the axial intensity of the fundamental harmonic in a perfectly aligned case.

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  • PHOTOINJECTOR FOR 6 MEV S-BAND RF LINAC AT ILT ILE OSAKA-UNIVERSITY Reviewed

    M FUJITA, K IMASAKI, J CHEN, S KURUMA, H FURUKAWA, C YAMANAKA, M ASAKAWA, N SAKAMOTO, T YAMAMOTO, N INOUE, S NAKAI, K NAGAMI, Y TSUNAWAKI, T AGARI, T ASAKUMA, N OHIGASHI

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   341 ( 1-3 )   ABS35 - ABS36   1994.3

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  • DEVELOPMENT OF A COMPACT HIGH-BRIGHTNESS X-RAY SOURCE Reviewed

    J CHEN, K IMASAKI, M FUJITA, C YAMANAKA, M ASAKAWA, S NAKAI, T ASAKUMA

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   341 ( 1-3 )   346 - 350   1994.3

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    Based on the concept of interacting electron with intense light stored in a supercavity, a compact and high brightness soft X-ray source has been proposed for lithography at ILT/ILE. For the purpose of enhancing the collision frequency of electron-photon beams, the idea of a combination of a supercavity pumped by a cw diode laser with an electrostatic dc accelerator has been put forward, for which a high average spectral brightness of 1.79 x 10(17) with a wavelength of 9.8 angstrom, and a bandwidth of 0.17% can be expected. Two other upgraded systems for the production of high peak brightness X-ray radiation and high brightness gamma-ray radiation have also been proposed, which are based on an ultrahigh power laser (2 TW, 5 ps) and a compact electron storage ring (300 MeV/89.3 mA). Meanwhile, the prototype laser undulator system and the current experiments on photon storage in a Fabry-Perot cavity pumped by a high power mode-locked Nd: YAG laser (25 MW, 89.25 MHz) are introduced.

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  • DEVELOPMENT OF A COMPACT FEL SYSTEM WITH A WIDE WAVELENGTH RANGE Reviewed

    K IMASAKI, M ASAKAWA, J CHEN, N SAKAMOTO, T YAMAMOTO, N OHIGASHI, Y TSUNAWAKI, K MIMA, S KURUMA, S NAKAI, C YAMANAKA

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   331 ( 1-3 )   232 - 234   1993.7

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    A compact FEL system is developed at ILT/ILE, Osaka, Japan. The wavelength range from mm to several mum in infrared and soft X-ray generation using a laser undulator is expected.

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  • HIGHER HARMONIC-GENERATION IN A MODIFIED WIGGLER MAGNETIC-FIELD Reviewed

    M ASAKAWA, K MIMA, S NAKAI, K IMASAKI, C YAMANAKA

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   318 ( 1-3 )   538 - 545   1992.7

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    Analysis is performed for higher harmonic generation on a modified wiggler.

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  • レーザー装置 その1

    車信 一郎, 鳴尾 誠浩, 三間 圀興, 大東 延久, 中井 貞雄, 山中 千代衛, 岡崎 徹, 今崎 一夫, 秋葉 龍郎, 綱脇 恵章, 小林 明, 川田 豊, 大谷 英成, 吉田 昌只, 青木 宗和, 森井 健, 宮本 修治, 細田 義門, 浅川 誠, 安芸 寿彦, 河村 良行, 豊田 浩一, 李 炳鐡, 松島 恭治, 東田 憲佳, 曽我部 伸, 村井 昭, 有安 富雄, 葛本 昌樹, 竹中 裕司, 森安 雅治, 安井 公治, 畑中 秀和, 河原 暢郎, 緑川 克美, 田代 英夫, 小原 實, 外園 博一, 小林 直樹, 志水 裕一, 土志田 実, 片田 毅, 三木 弘次郎, 松島 朋史, 末田 正, 西前 順一, 吉沢 憲治, 熊本 健二, 八木 重典, 小方 大成, 鎌上 則夫, 谷脇 学, 佐藤 俊一, 和仁 郁雄, 尾角 英毅, 室 幹雄, 藤井 洋郎, 中尾 雅俊, 竹田 哲也, 出口 博史, 藤原 閲夫, 井澤 靖和, 渡辺 郁男, 林 和夫, 野田 悦夫, 鈴木 節雄, 小川 朋子, 井関 康, 森宮 脩, 小林 徳康, 木村 博信, 小長井 主税, 白山 新平, 宮沢 竜雄, 高橋 知幸, 青木 延忠, 藤原 淳史, 深澤 輝一郎, 田中 祥夫, 石橋 誠, 佐藤 俊雄, 興 雄司, 出羽 達也, 田代 英二, 本田 親久, 前田 三男, 長谷川 芳夫, 二見 博, 泉 順, 松田 桂一, 大向 雅人, 本越 伸二, 川口 誠二, 前川 晴夫, 吉田 英次, 松本 康孝, 小松 由和, 中原 秀起, 葛生 伸, 村原 正隆, 滝沢 本承, 伊沢 孝男, 山村 史彦, 内村 龍二, 橋本 至, 薬王 輝雄, 大和田野 芳郎, 松本 裕治, 矢野 雅昭

    レーザー研究   19   31 - 60   1991

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    DOI: 10.2184/lsj.19.Supplement_31

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  • EXPERIMENTAL STUDIES OF FAR INFRARED FREE-ELECTRON LASER ON INDUCTION ACCELERATOR Reviewed

    T AKIBA, M MOKUNO, H YOSHIOKA, H OHTANI, M ASAKAWA, S TANIOKA, S MIYAMOTO, K IMASAKI, K MIMA, S KURUMA, N OHIGASHI, Y TSUNAWAKI, C YAMANAKA, S NAKAI

    PROCEEDINGS OF THE EIGHTH INTERNATIONAL CONFERENCE ON HIGH-POWER PARTICLE BEAMS ( BEAMS 90 ), VOLS 1 AND 2   1111 - 1116   1991

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MISC

  • Single-shot spatio-temporal measurement of relativistic electron beams by electro-optic sampling

    Masato Ota, Koichi Kan, Youwei Wang, Verdad C. Agulto, Yasunobu Arikawa, Makoto R. Asakawa, Youichi Sakawa, Tatsunosuke Matsui, Makoto Nakajima

    Real-time Measurements, Rogue Phenomena, and Single-Shot Applications IX   2024.3

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    Publishing type:Research paper, summary (international conference)   Publisher:SPIE  

    DOI: 10.1117/12.3005230

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  • Ultrafast Dynamics of Coulomb Electric Field Contraction by Relativistic Electron Bunch

    M. Nakajima, M. Ota, K. Kan, Y.W. Wang, V. C. Agulto, K. Kato, Y. Arikawa, T. Matsui, M.R. Asakawa

    2023 48th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)   2023.9

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    DOI: 10.1109/irmmw-thz57677.2023.10298935

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  • Observation of Third Harmonic Generation in Two-Dimensional MoS<sub>2</sub> Semiconductor Using Terahertz Free-Electron Laser

    Youwei Wang, Masato Ota, Verdad C. Agulto, Valynn Katrine Mag-Usara, Mikihiko Nishitani, Goro Isoyama, Makoto Asakawa, Makoto Nakajima

    2022 47th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)   2022.8

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    DOI: 10.1109/irmmw-thz50927.2022.9895747

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  • Laser-Induced Periodic Surface Structures on Ge2Sb2Te5 Irradiated by Terahertz Free-Electron Laser Vortex Beam

    Youwei Wang, Sadashi Segawa, Tomoki Shimizu, Masato Ota, Verdad C. Agulto, Valynn Katrine Mag-Usara, Katsuhiko Miyamoto, Takashige Omatsu, Kotaro Makino, Junji Tominaga, Goro Isoyama, Makoto Asakawa, Makoto Nakajima

    2022 47th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)   2022.8

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    DOI: 10.1109/irmmw-thz50927.2022.9895678

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  • Spintronic Terahertz Emission and Magnetic Anisotropy of Epitaxial Platinum Heterostructures on MgO(110) Substrate

    Shoei Tetsukawa, Shuang Liu, Valynn Katrine Mag-Usara, Verdad Canila Agulto, Makoto Kohda, Ryan Thompson, Hiromu Gamou, Ye Du, Shutaro Karube, Junsaku Nitta, Masahiko Tani, Makoto Asakawa, Makoto Nakajima

    2021 46th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)   2021.8

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    DOI: 10.1109/irmmw-thz50926.2021.9566960

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  • Terahertz emission amplitude-based 2D mapping of the Fe thickness profile in Fe/Pt spintronic heterostructure

    Y. Koike, S. Tetsukawa, M. Nishitani, H. Kitahara, V. K. P. Mag-usara, M. Asakawa, M. Yoshimura, M. Tani, M. Nakajima

    2020 45th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)   2020.11

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    DOI: 10.1109/irmmw-thz46771.2020.9370658

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  • Coherent Smith-Purce radiation emitted by electron bunches produced by photo injector

    26 ( 1 )   50 - 55   2016.8

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  • Amplification Process of Cherenkov Free-Electron Laser Driven by Low-Energy Electron Beam

    ASAKAWA Makoto

    88 ( 10 )   594 - 598   2012.10

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  • Terahertz radiation source based on Cherenkov radiation

    ASAKAWA Makoto R., YAMAGUCHI Soichiro, SEKI Masako, TSUNAWAKI Yoshiaki

    2010 ( 1 )   7 - 12   2010.1

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  • Suitable Property of Nickel Plate for Adiabatic Transition Part in Solenoid-Induced Wiggler

    Nobuhisa Ohigashi, Yoshiaki Tsunawaki, Makoto R. Asakawa

    JAPANESE JOURNAL OF APPLIED PHYSICS   48 ( 11 )   114504-1~8   2009.11

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    An adiabatic transition field in a solenoid-induced helical wiggler has been successfully generated using staggered Ni plates with different thicknesses of 6 to 0.1 mm. However, trials using Fe plates instead of Ni plates failed to generate a suitable adiabatic transition field To elucidate these phenomena, the magnetic behavior of Ni and Fe plates with regard to the thickness dependence was studied by a fundamental electromagnetic calculation with the aid of a field calculation based on the finite element method The magnetic flux density of a Ni plate increases and then decreases with the reduction in thickness from 6 to 0.8 mm and from 0 8 to 0 1 mm, respectively On the other hand. the magnetic flux density of an Fe plate does not have a maximum but monotonically increases until the smallest thickness of 0.1 mm. The dependence of magnetic flux density on thickness differs between Ni and Fe plates This difference explains the necessity of using a Ni plate for the adiabatic transition part of the wiggler. Furthermore, we estimated three types of demagnetizing factor depending on the thickness of the plate. (C) 2009 The Japan Society of Applied Physics

    DOI: 10.1143/JJAP.48.114504

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  • 28pZB-11 Development of compact cherenkov FEL sources

    Yamaguchi S.

    Meeting abstracts of the Physical Society of Japan   64 ( 1 )   112 - 112   2009.3

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  • A compact electron gun using field emitter array Reviewed

    M. R. Asakawa, A. Ikeda, N. Miyabe, S. Yamaguchi, M. Kusaba, Y. Tsunawaki

    THIN SOLID FILMS   517 ( 4 )   1493 - 1496   2008.12

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    A compact electron gun using field emitter array has been developed. With a simple triode configuration consisting of FEA, mid-electrode and anode electrode, the electron gun produces a parallel beam with a diameter of 0.5 mm. This electron gun is applicable for compact radiation sources such as Cherenkov free-electron lasers. (c) 2008 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.tsf.2008.09.026

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  • Applications of infrared free electron laser for the research on semiconductor

    Journal of the Japan Society of Infraed Science and Technolog   16 ( 2 )   76 - 85   2007.10

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  • Dynamics of low coupling parameter free-electron laser oscillator

    H Nishiyama, M Asakawa, Y Tsunawaki, M Heya, K Awazu, K Imasaki

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   507 ( 1-2 )   74 - 78   2003.7

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    Effects of bunch length fluctuation on FEL output are studied experimentally and numerically. The FEL energy drops quasi-periodically in the saturation regime except for certain detuning. The observation of the change in bunch length reveals that the elongation of the bunch length causes these dips. A one-dimensional numerical simulation can reproduce the effect of the elongation of bunch length on the FEL output qualitatively. (C) 2003 Elsevier Science B.V. All rights reserved.

    DOI: 10.1016/S0168-9002(03)00841-6

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  • Dynamics of low coupling parameter free-electron laser oscillator

    H Nishiyama, M Asakawa, Y Tsunawaki, M Heya, K Awazu, K Imasaki

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   507 ( 1-2 )   74 - 78   2003.7

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    Effects of bunch length fluctuation on FEL output are studied experimentally and numerically. The FEL energy drops quasi-periodically in the saturation regime except for certain detuning. The observation of the change in bunch length reveals that the elongation of the bunch length causes these dips. A one-dimensional numerical simulation can reproduce the effect of the elongation of bunch length on the FEL output qualitatively. (C) 2003 Elsevier Science B.V. All rights reserved.

    DOI: 10.1016/S0168-9002(03)00841-6

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  • A 100 MW far-infrared free-electron laser driven by a 180 MeV RF-linac

    M Asakawa, H Nishiyama, K Gotoda, N Ohigashi, Y Tsunawaki, K Imasaki

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   483 ( 1-2 )   286 - 290   2002.5

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    The development of a 100 MW far-infrared free-electron laser oscillator is reported. By using a 180 MeV electron beam, this system will provide the high power and the rapid scanning of the broad wavelength range. 10-100 mum, to enhance the user programs. The intracavity power of several GWs will be used for Compton back scattering X- or gamma-ray generation. To store such an intense radiation, the dynamics of the FEL oscillator with a coupling parameter mu(c) less than or equal to 1 which is defined as the ratio of the slippage distance and the electron bunch length, was investigated experimentally oil the operating mid-infrared system. (C) 2002 Elsevier Science B.V. All rights reserved.

    DOI: 10.1016/S0168-9002(02)00329-7

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  • A 100 MW far-infrared free-electron laser driven by a 180 MeV RF-linac

    M Asakawa, H Nishiyama, K Gotoda, N Ohigashi, Y Tsunawaki, K Imasaki

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   483 ( 1-2 )   286 - 290   2002.5

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    The development of a 100 MW far-infrared free-electron laser oscillator is reported. By using a 180 MeV electron beam, this system will provide the high power and the rapid scanning of the broad wavelength range. 10-100 mum, to enhance the user programs. The intracavity power of several GWs will be used for Compton back scattering X- or gamma-ray generation. To store such an intense radiation, the dynamics of the FEL oscillator with a coupling parameter mu(c) less than or equal to 1 which is defined as the ratio of the slippage distance and the electron bunch length, was investigated experimentally oil the operating mid-infrared system. (C) 2002 Elsevier Science B.V. All rights reserved.

    DOI: 10.1016/S0168-9002(02)00329-7

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  • 25aWM-3 Magnetic Field Analysis of Hybrid Helical Wiggler with Multi Poles per Period

    Tsunawaki Yoshiaki, Ohigashi Nobuhisa, Asakawa Makoto, Imasaki Kazuo, Mima Kunioki

    Meeting abstracts of the Physical Society of Japan   57 ( 1 )   131 - 131   2002.3

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  • 光源

    日本赤外線学会誌   12   7 - 11   2002

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  • Doppler-shifted cyclotron absorption of electron Bernstein waves via N-parallel to-upshift in a Tokamak plasma

    T Maekawa, T Kobayashi, S Yamaguchi, K Yoshinaga, H Igami, M Uchida, H Tanaka, M Asakawa, Y Terumichi

    PHYSICAL REVIEW LETTERS   86 ( 17 )   3783 - 3786   2001.4

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    Extraordinary (X) waves are perpendicularly injected for electron Bernstein (B) wave heating into an Ohmically heated plasma from the inboard side in the WT-3 tokamak. Measurements show that absorption does not take place at the electron cyclotron resonance layer nor the upper hybrid resonance layer, but does happen midway between them. This is consistent with the ray tracing prediction, i.e., the poloidal field and poloidal inhomogeneity of toroidal field lead the B waves to have a large parallel refractive index N-parallel to (&gt;1), and the B waves are damped away via the Doppler-shifted cyclotron resonance.

    DOI: 10.1103/PhysRevLett.86.3783

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  • A FIR Free-Electron Laser using the Photocathode/RFgun accelerator

    Asakawa M.

    Meeting abstracts of the Physical Society of Japan   56 ( 1 )   146 - 146   2001.3

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  • Low aspect ratio ECR toroidal plasma (LATE)

    Taoka Hidekazu

    Meeting abstracts of the Physical Society of Japan   55 ( 1 )   155 - 155   2000.3

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  • Peripheral heating of plasma using electron Bernstein wave

    Kobayashi Tsutomu

    Meeting abstracts of the Physical Society of Japan   55 ( 1 )   134 - 134   2000.3

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  • ECR Plasma in a stuffed cusp field

    Uchida Masaki

    Meeting abstracts of the Physical Society of Japan   55 ( 1 )   183 - 183   2000.3

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  • ECR plasma in quadrupole magnetic field

    Asakawa M.

    Meeting abstracts of the Physical Society of Japan   55 ( 1 )   182 - 182   2000.3

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  • Diocotron Oscillation in Pure Electron Plasmas with Multi-Pulse Stacking Method

    Uchida H.

    Meeting abstracts of the Physical Society of Japan   55 ( 1 )   161 - 161   2000.3

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  • Suppression of a pressure driven m=1 mode in a lower hybrid current drive plasma by electron cyclotron heating in the WT-3 tokamak

    S Yoshimura, M Watanabe, K Tanabe, A Nakayama, M Asakawa, T Maehara, M Nakamura, H Tanaka, T Maekawa, Y Terumichi

    PHYSICS OF PLASMAS   7 ( 1 )   276 - 282   2000.1

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    A pressure driven m = 1/n = 1 mode is excited by lower hybrid current drive in the WT-3 tokamak [T. Maehara et al., Nucl. Fusion 38, 39 (1998)]. The excitation of the mode is accompanied with the decrease of the magnetic shear and with the peaking of the soft x-ray emissivity profile inside the q = 1 surface. The crescent-shaped mode structure appeared on the contour map of the soft x-ray emissivity is consistent with that of the quasi-interchange mode. The m = 1 mode can be suppressed by electron cyclotron heating near the q = 1 surface. The range of the location of the electron cyclotron resonance layer effective for the complete suppression is much wider and the time scale for the suppression is much faster than those in the case of the suppression of the tearing mode in the ohmic heating plasma. (C) 2000 American Institute of Physics. [S1070-664X(00)03301-2].

    DOI: 10.1063/1.873823

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  • 26aYN-2 Cyclotron Resonance in Pure Electron Plasmas

    Tanaka H

    Meeting abstracts of the Physical Society of Japan   54 ( 2 )   168 - 168   1999.9

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  • 27aYN-7 Production of low aspect ratio ECR toroidal plasma

    Taoka Hidekazu

    Meeting abstracts of the Physical Society of Japan   54 ( 2 )   185 - 185   1999.9

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  • 27aYN-6 Plasma Production with a Spheroidal ECR Surface

    Uchida Masaki

    Meeting abstracts of the Physical Society of Japan   54 ( 2 )   185 - 185   1999.9

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  • 26aYG-5 Soft X-ray Computerized Tomography of Sawteeth on Three Minor Cross-Sections in WT-3

    Yamaguchi Souichirou

    Meeting abstracts of the Physical Society of Japan   54 ( 2 )   165 - 165   1999.9

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  • Electron cyclotron resonance plasma produced with a closed spheroidal electron cyclotron resonance surface in a simple cusp field

    M Uchida, S Fukumoto, M Asakawa, H Tanaka, T Maekawa, Y Terumichi

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS   38 ( 8A )   L885 - L887   1999.8

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    With a spheroidal electron cyclotron resonance (ECR) surface completely enclosed in a vacuum vessel in a simple cusp field, we can produce ECR plasmas with a peak electron density up to n(e) similar or equal to 5 x 10(11) cm(-3) at a low Ar pressure of p similar or equal to 1.5 x 10(-5) Torr by injection of 2.45 GHz microwave power of P-in = 150-400 W. The degree of ionization reaches over 50% at this local density peak point. Such a high degree of ionization may be due to the efficient ionization by suprathermal tail electrons (W &gt; 30 eV), which are observed in single probe characteristics. On the other hand, at a relatively high pressure of p similar or equal to 1.5 x 10(-4) Torr, a flat density profile with density nearly equal to the plasma cutoff density (7 x 10(10) cm(-3)) is obtained inside the ECR spheroid.

    DOI: 10.1143/jjap.38.L885

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  • Plasma Production with a Spheroidal ECR Surface in a simple cusp field

    UCHIDA Masaki, ASAKAWA Makoto, TANAKA Hitoshi, MAEKAWA Takashi, TERUMICHI Yasushi

    1999 ( 19 )   43 - 47   1999.6

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  • 31p-XM-2 ECR plasma in a cusp field II

    Uchida Masaki

    Meeting abstracts of the Physical Society of Japan   54 ( 1 )   842 - 842   1999.3

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  • 30p-XL-6 Electron cyclotron current drive experiment with an elliptically polarized micro-wave injection

    Asakawa Makoto

    Meeting abstracts of the Physical Society of Japan   54 ( 1 )   821 - 821   1999.3

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  • 30p-XL-5 Simultaneous mesurement of soft X-ray computer tomography in the plural cross-section

    Yamaguchi Souichirou

    Meeting abstracts of the Physical Society of Japan   54 ( 1 )   821 - 821   1999.3

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  • 31p-XM-1 ECR plasma in the Cusp magnetic field by Permanent Magnet

    Hyodo Y., Moriwaki M., Yamashita T., Uchida M., Asakawa M., Tanaka H., Maekawa T., Terumichi Y.

    Meeting abstracts of the Physical Society of Japan   54 ( 1 )   842 - 842   1999.3

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  • On-Axis Current Drive Experiment Using a Quasi-Optical Electron Cyclotron Heating/Current Drive System on the WT-3 Tokamak

    ASAKAWA Makoto, HIRAGI Toshiyuki, YAMAGUCHI Souichirou, YOSHINAGA Kazuhiro, IGAMI Hiroe, TERUMICHI Yasushi, UCHIDA Masaki, KOBAYASHI Tutomu, TANAKA Hitoshi, MAEKAWA Takashi, NAKAMURA Masahiko, OHKUBO Kunizo, KUBO Shin, NAGASAKI Kazunobu

    Kakuyūgō kenkyū   75 ( 6 )   732 - 740   1999

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    An 89 GHz quasi-optical Electron Cyclotron Heating (ECH)/Current Drive (ECCD) system has been installed on the WT-3 tokamak. In order to investigate the effect of localized ECH/ECCD on the MHD instabilities, this system is designed to focus the micro-wave beam into a small focal spot with the radius about 1cm in the plasma center. This radius is smaller than the inversion radius of the sawtooth oscillation observed in WT-3. Utilizing this feature, the experiment on control of sawtooth oscillation by on-axis current drive have been performed. Stabilization of sawtooth by counter-ECCD is observed when the power deposition is localized inside the inversion radius. This result may be due to the decrease in current density near the magnetic axis. For the optimal coupling of the micro-wave to obliquely propagating waves at the plasma surface, a linear-elliptical polarization converter has been installed recently. This polarization converter may raise the effective current drive efficiency by a factor of 1.5 for the injected micro-wave power.

    DOI: 10.1585/jspf.75.732

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    Other Link: http://dl.ndl.go.jp/info:ndljp/pid/10453640

  • On-Axis Current Drive Experiment Using a Quasi-Optical Electron Cyclotron Heating/Current Drive system on the WT-3 tokamak

    Makoto ASAKAWA, Toshiuki HIRAGI, Souichirou YAMAGUCHI, Kazuhiro YOSHINAGA, Hiroe IGAMI, Yasushi TERUMICHI, Masaki UCHIDA, Tutomu KOBAYASHI, Hitoshi TANAKA, Takashi MAEKAWA, Masahiko NAKAMURA, Kunizo OHKUBO, Shin KUBO, Kazunobu NAGASAKI

    Journal of Plasma and Fusion Research   75 ( 6 )   732 - 740   1999

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    An 89 GHz quasi-optical Electron Cyclotron Heating (ECH)/Current Drive (ECCD) system has been installed on the WT-3 tokamak. In order to investigate the effect of localized ECH/ECCD on the MHD instabilities, this system is designed to focus the micro-wave beam into a small focal spot with the radius about 1cm in the plasma center. This radius is smaller than the inversion radius of the sawtooth oscillation observed in WT-3. Utilizing this feature, the experiment on control of sawtooth oscillation by on-axis current drive have been performed. Stabilization of sawtooth by counter-ECCD is observed when the power deposition is localized inside the inversion radius. This result may be due to the decrease in current density near the magnetic axis. For the optimal coupling of the micro-wave to obliquely propagating waves at the plasma surface, a linear-elliptical polarization converter has been installed recently. This polarization converter may raise the effective current drive efficiency by a factor of 1.5 for the injected micro-wave power.

    DOI: 10.1585/jspf.75.732

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    Other Link: http://dl.ndl.go.jp/info:ndljp/pid/10453640

  • Formation of Non-neutral Ion Plasmas with the Multi-pulse Stacking Method

    SODEKODA Tatsuya

    Meeting abstracts of the Physical Society of Japan   53 ( 2 )   940 - 940   1998.9

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  • ECR plasma in cusp field

    ASAKAWA Makoto

    Meeting abstracts of the Physical Society of Japan   53 ( 2 )   929 - 929   1998.9

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  • Observation of LHCD fast electrons by ECA

    UTIDA Masaki

    Meeting abstracts of the Physical Society of Japan   53 ( 2 )   960 - 960   1998.9

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  • 300ch Troidal and Poloidal Soft X-ray Computerized Tomography System

    YAMAGUCHI Souichirou

    Meeting abstracts of the Physical Society of Japan   53 ( 2 )   960 - 960   1998.9

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  • ECCD using elliptically polarized rf injection

    HIRAGI Toshiyuki

    Meeting abstracts of the Physical Society of Japan   53 ( 2 )   960 - 960   1998.9

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  • Long Time Confinement of a Non-neutral Plasma by Applying a Tilting Electrostatic Mode

    TANAKA H., SODEKODA T., ENYA T., MAEKAWA T., NAKAMURA M., ASAKAWA M., TERUMICHI Y.

    Meeting abstracts of the Physical Society of Japan   53 ( 2 )   940 - 940   1998.9

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  • Experiments on Long-time Confinement of Nonneutral Electron Plasmas in the NNP-1 Device

    YAMAGUCHI Souichirou

    Meeting abstracts of the Physical Society of Japan   53 ( 1 )   832 - 832   1998.3

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  • Cusp field and ECR plasma

    Meeting abstracts of the Physical Society of Japan   53 ( 1 )   821 - 821   1998.3

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  • Formation of Non-neutral Electron Plasmas with Field Emitter Array Cathode

    SODEKODA Tatsuya

    Meeting abstracts of the Physical Society of Japan   53 ( 1 )   832 - 832   1998.3

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  • Experiments on Solitary Wave Excitation and Propagation in a Non-neutral Electron Plasma

    TANAKA Hitosi

    Meeting abstracts of the Physical Society of Japan   53 ( 1 )   832 - 832   1998.3

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  • Sawtooth control by on-axis electron cyclotron current drive on the WT-3 tokamak

    Proc. 17th IAEA Fusion Energy Conf. , IAEA-cn69/CDP/06   1998

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  • 7a-YM-8 Effect of Rotating-Electric Fields on Confinement of a Nonneutral Electron Plasma

    Yamaguchi Souichirou

    Meeting abstracts of the Physical Society of Japan   52 ( 2 )   935 - 935   1997.9

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  • 7a-YM-7 Experiments on Solitary Waves in a Non-neutral Electron Plasma

    Nagatomo Tamio

    Meeting abstracts of the Physical Society of Japan   52 ( 2 )   934 - 934   1997.9

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  • 国際会議報告第3回「プラズマ中の大電力マイクロ波」国際ワークショップ

    出原 敏孝, 長崎 百伸, 浅川 誠

    プラズマ・核融合学会誌 = Journal of plasma and fusion research   72 ( 12 )   1427 - 1429   1996.12

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  • Multi-order harmonic lasing with a modified wiggler

    M Asakawa, N Nakao, H Ohkubo, T Ishida, T Watanabe, E Yasuda, Y Okuda, M Fujita, J Chen, A Moon, PK Roy, S Kuruma, K Imasaki, K Mima, N Ohigashi, Y Tsunawaki, S Nakai, C Yamanaka

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   375 ( 1-3 )   416 - 419   1996.6

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    A novel modified wiggler for higher harmonic lasing, modified wiggler, has been developed at ILT/ILE. Its magnetic field is expressed as the sum of the harmonic magnetic field components. A trial modified wiggler produced a considerable harmonic field component. A modification ratio, B-3/B-1, of more than 10% was achieved. Using this wiggler, we observed the enhanced 3rd harmonic spontaneous emission. Further, the development of a modified wiggler for harmonic lasing will be presented.

    DOI: 10.1016/0168-9002(95)01383-0

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  • 1p-YL-7 Nonlinear evolution of radiation spectrum in a waveguide FEL oscillator using short electron micropulses

    Goto M., Kuruma S., Mima K., Ohigashi N., Asakawa M., Fujita M., Imasaki K, Yamanaka C.

    Abstracts of the meeting of the Physical Society of Japan. Annual meeting   51 ( 4 )   185 - 185   1996.3

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  • Localized plasma heating experiments using a quasi-optical ECH system on the WT-3 tokamak(共著)

    Proceedings of the 1996 International Conference on Plasma Physics   9I01   1996

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  • 28a-R-4 自由電子レーザー高次高調波発振用ウィグラーの開発

    中尾 直也, 浅川 誠, 陳 基忠, 大久保 宏一, 石田 敬之, 渡辺 剛史, 奥田 喜彦, 大東 延久, 綱脇 恵章, 藤田 雅之, 文 雅司, 安田 英司, ロイ プラビール, 今崎 一夫, 中井 貞雄, 三間 圀興, 山中 千代衛

    日本物理学会講演概要集. 秋の分科会   1995 ( 4 )   165 - 165   1995.9

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  • 28a-R-9 光共振器内でのコンプトン散乱を用いた小型高輝度光源の開発

    文 雅司, 藤田 雅之, 安田 英司, ロイ プラビール, 大久保 宏一, 陳 基忠, 今崎 一夫, 浅川 誠, 中尾 直也, 石田 敬之, 渡辺 剛史, 奥田 喜彦, 大東 延久, 綱脇 恵章, 三間 圀興, 中井 貞雄, 山中 千代衛

    日本物理学会講演概要集. 秋の分科会   1995 ( 4 )   167 - 167   1995.9

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  • 28a-R-5 Development of Electoromagnetic Helical-Micro-Wiggler (V) : Measurement of Test-Wigller for Suppression of Leakage Field

    Ishida T., Ohigashi N., Tunawaki Y., Nakao N., Moon A., Yasuda E., Watanabe T., Okuda Y., Ohkubo K., Roy P., Chen J., Asakawa M., Fujita M., Kuruma S., Imasaki K., Nakai S., Yamanaka C., Mima K.

    Abstracts of the meeting of the Physical Society of Japan. Sectional meeting   1995 ( 4 )   165 - 165   1995.9

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  • 28a-R-6 Study of the high brightness electorn RF-gun with Tungsten photo Cathode

    Abstracts of the meeting of the Physical Society of Japan. Sectional meeting   1995 ( 4 )   166 - 166   1995.9

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  • 28a-R-3 Research on broad-range free-electron laser

    Abstracts of the meeting of the Physical Society of Japan. Sectional meeting   1995 ( 4 )   164 - 164   1995.9

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  • 28a-R-7 Study of VUV free electron laser with DFB cavity

    Chen J.Z., Okubo K., Fujita M., Asakawa M., Moon A., Nakao N., Roy P.K., Ohigashi N., Tsunawaki Y., Mima K., Nakai S., Yamanaka C.

    Abstracts of the meeting of the Physical Society of Japan. Sectional meeting   1995 ( 4 )   166 - 166   1995.9

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  • 28a-R-2 Numerical analysis of coherent radiation in waveguide FEL oscillator.

    Goto M., Kuruma S., Mima K., Ohigashi N., Asakawa M., Fujita M., Imasaki K., Yamanaka C.

    Abstracts of the meeting of the Physical Society of Japan. Sectional meeting   1995 ( 4 )   164 - 164   1995.9

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  • CALCULATION OF A TRANSVERSE OPTICAL-MODE AND DIFFRACTION LOSS IN A SUPERCAVITY

    J CHEN, M FUJITA, M ASAKAWA, K IMASAKI, S NAKAI, C YAMANAKA

    OPTICS COMMUNICATIONS   119 ( 5-6 )   563 - 568   1995.9

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    In this paper, we present a simulation of the dynamic procedure of the photon storage in a practical supercavity (R = 99.99%) pumped by a circular symmetric Gaussian beam. The Fox-Li technique has been used to numerically calculate the field distribution, the diffraction losses, and the round-trip phase shift of TEM(0n) modes. A concept of an effective Fresnel number is put forward. Details of the Fox-Li type calculation are introduced along with the discussions of the convergence in solutions of the iterative equations. The effects of the refraction index of the e-beam and the loss of Compton backscattering by the e-beam inside the cavity are discussed.

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  • Development of Compact FEL System with Photocathode RF Gun

    IMASAKI Kazuo, FUJITA Masayuki, ASAKAWA Makoto

    215   15 - 20   1995.5

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  • DEVELOPMENT OF A MODIFIED WIGGLER FOR HIGHER HARMONIC LASING OF A FREE-ELECTRON LASER

    M ASAKAWA, N INOUE, K MIMA, S NAKAI, K IMASAKI, M FUJITA, J CHEN, C YAMANAKA, N NAKAO, T AGARI, T ASAKUMA, A MOON, N OHIGASHI, T MINAMIGUCHI, Y TSUNAWAKI

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   358 ( 1-3 )   399 - 402   1995.4

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    A modified wiggler, with enhanced harmonic fields, was developed for free-electron laser higher harmonic lasing. The harmonic wiggler field was produced by arranging high-permeability shims in the gap spacing of a four-block-per-period Halbach design wiggler. By this method, the 3rd harmonic wiggler field exceeded 18% of the fundamental field. The phasing of the harmonic field could be also controlled by the positioning of the shims.

    DOI: 10.1016/0168-9002(94)01269-5

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  • Study of short wavelength FELs based on Self Amplified Spontaneous Emission

    1995 ( 11 )   61 - 68   1995.3

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  • 28a-YX-6 スーパーキャビティーを用いた小型X線源の開発(I)

    藤田 雅之, 朝熊 孝, 陳 基忠, 南口 経昭, 文 雅司, 今崎 一夫, 浅川 誠, 井上 尚樹, 上利 達雄, 中尾 直也, プラビール ロイ, 大東 延久, 綱脇 恵章, 三間 圀興, 中井 貞雄, 山中 千代衛

    日本物理学会講演概要集. 年会   50 ( 4 )   131 - 131   1995.3

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  • 28a-YX-4 X線領域自由電子レーザーの自己増幅自然放射(SASE)に関する研究

    陳 基忠, 藤田 雅之, 朝熊 孝, 南口 経昭, 文 雅司, 今崎 一夫, 浅川 誠, 中尾 直也, 井上 尚樹, 上利 達雄, プラビール ロイ, 大東 延久, 綱脇 恵章, 三間 圀興, 中井 貞雄, 山中 千代衛

    日本物理学会講演概要集. 年会   50 ( 4 )   130 - 130   1995.3

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  • 28a-YX-2 コンパクトRF加速器によるFEL実験II

    中尾 直也, 浅川 誠, 藤田 雅之, 陳 基忠, 今崎 一夫, 上利 達雄, 井上 尚樹, 朝熊 孝, 文 雅司, 南口 経昭, 大東 延久, 綱脇 恵章, 三間 圀興, 中井 貞雄, 山中 千代衛

    日本物理学会講演概要集. 年会   50 ( 4 )   129 - 129   1995.3

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  • Analysis of detuning curve of waveguide FEL oscillator using RF linac

    Goto M., Kuruma S., Mima K., Ohigashi N., Asakawa M., Fujita M., Imasaki K., Yamanaka C., Nakai S.

    Abstracts of the meeting of the Physical Society of Japan. Annual meeting   50 ( 4 )   132 - 132   1995.3

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  • Development of Electromagnetic Helical-Micro-Wiggler(IV) : Mechanism of suppression and control for leakage fields

    Ohigashi N., Gotanda Y., Iwahashi T., Yomogi H., Tsunawaki Y., Mima K., Asakawa M., Fujita M., Kuruma S., Imasaki K., Yamanaka C., Nakai S.

    Abstracts of the meeting of the Physical Society of Japan. Annual meeting   50 ( 4 )   129 - 129   1995.3

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  • FEL experiment on a compact RFlinac

    Abstracts of the meeting of the Physical Society of Japan. Annual meeting   50 ( 4 )   130 - 130   1995.3

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  • 28a-YX-5 スーパーキャビティーを用いた小型X線源の開発(II)

    文 雅司, 藤田 雅之, 陳 基忠, 今崎 一夫, 浅川 誠, 井上 尚樹, 上利 達雄, 朝熊 孝, 中尾 直也, プラビール ロイ, 南口 経昭, 大東 延久, 綱脇 恵章, 三間 圀興, 中井 貞雄, 山中 千代衛

    日本物理学会講演概要集. 年会   50 ( 4 )   131 - 131   1995.3

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  • Development of Photocathode RF Gun Driven by a Pulsed Nd : YAG Laser

    FUJITA Masayuki, FURUKAWA Hiroyuki, CHEN Jizhong, IMASAKI Kazuo, YAMANAKA Chiyoe, ASAKAWA Makoto, INOUE Naoki, NAKAI Sadao, AGARI Tatsuo, OHIGASHI Nobuhisa

    The Review of laser engineering   23 ( 1 )   43 - 54   1995.1

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  • Developement of a modified wiggler for higher harmonic lasing of free-electron laser

    15   58 - 58   1995.1

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  • Study of a compact FEL using an rf linac

    15   57 - 57   1995.1

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  • Development of Compact High-Brightness X-ray Sources

    15   63 - 63   1995.1

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  • Development of a Photocathode for Free-Electron Lasers.

    ASAKAWA Makoto, FUJITA Masayuki, IMASAKI Kazuo, YAMANAKA Chiyoe, NAKAI Sadao

    rle   23 ( 1 )   55 - 67   1995

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    We developed a metallic photocathode to produce a high-brightness electron beam for freeelectron lasers. Single crystalline lanthanum hexaboride had a quantum yield exceeding 10<SUP>-4</SUP> at 1000 °C with a frequency-tripled Nd: YAG laser. A tungsten cathode, irradiated by a frequency-doubled Nd: YAG laser, emitted photo-electrons through the two-photon process. The quadratic dependence of the photo-current on the laser intensity could improve the low quantum yield of the multi-photon process. This tungsten photocathode is capable of generating an 1 kA/cm2 electron beam. Futher, heating of these materials could increase the quantum yield. With this technique, these cathodes will generate an electron beam, which has normalized brightness more than 10<SUP>11</SUP>A/m<SUP>2</SUP>/rad<SUP>2</SUP>, in a radio-frequency electron gun.

    DOI: 10.2184/lsj.23.55

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  • 5a-T-6 スーパーキャビティの横モードおよび回折損失

    陳 基忠, 藤田 雅之, 今崎 一夫, 浅川 誠, 朝熊 孝, 井上 尚樹, 上利 達雄, 文 雅可, 中尾 達也, 南口 恵昭, 大東 延久, 綱脇 恵章, 村井 昭, 三間 圀興, 中井 貞雄, 山中 千代衛

    日本物理学会講演概要集. 秋の分科会   1994 ( 4 )   211 - 211   1994.8

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  • 5a-T-2 光電陰極RF加速器による自由電子レーザーの研究 (II) : ビームコントロール

    井上 尚樹, 藤田 雅之, 今崎 一夫, 山中 千代衛, 浅川 誠, 上利 達雄, 朝熊 孝, 陳 基忠, 三間 圀興, 中井 貞雄, 中尾 直也, 文 雅司, 大東 延久, 南口 経昭, 綱脇 恵章

    日本物理学会講演概要集. 秋の分科会   1994 ( 4 )   209 - 209   1994.8

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  • 5a-T-7 Simulation of waveguide FEL oscillator using RF linac II

    Goto M, Kuruma S, Mima K, Ohigashi N, Asakawa M, Fujita M, Imasaki K, Yamanaka C, Nakai S

    Abstracts of the meeting of the Physical Society of Japan. Sectional meeting   1994 ( 4 )   211 - 211   1994.8

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  • 5a-T-4 コンパクトRF加速器による自由電子レーザーの研究 (IV)

    浅川 誠, 井上 尚樹, 上利 達雄, 朝熊 孝, 中尾 直也, 文 雅可, 南口 恵昭, 藤田 雅之, 陳 基忠, 大東 延久, 綱脇 恵章, 今崎 一夫, 三間 圀興, 山中 千代衛, 中井 貞雄

    日本物理学会講演概要集. 秋の分科会   1994 ( 4 )   210 - 210   1994.8

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  • 5a-T-5 スーパーキャビティと電子ビームの相互作用実験

    朝熊 孝, 陳 基忠, 藤田 雅之, 今崎 一夫, 山中 千代衛, 浅川 誠, 井上 尚樹, 三間 圀興, 中井 貞雄, 大東 延久, 上利 達雄, 中尾 直也, 文 雅司, 綱脇 恵章, 南口 恵昭

    日本物理学会講演概要集. 秋の分科会   1994 ( 4 )   210 - 210   1994.8

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  • 5a-T-1 光電陰極RF加速器による自由電子レーザーの研究 (I) : 総括

    藤田 雅之, 陳 基忠, 今崎 一夫, 古川 裕之, 山中 千代衛, 浅川 誠, 井上 尚樹, 三間 圀興, 中井 貞雄, 大東 延久, 朝熊 孝, 上利 達雄, 中尾 直也, 文 雅可, 綱脇 恵章, 南口 経昭

    日本物理学会講演概要集. 秋の分科会   1994 ( 4 )   208 - 208   1994.8

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  • 5a-T-3 光電陰極RF加速器による自由電子レーザーの研究 (III) : 電子ビーム計測

    上利 達雄, 浅川 誠, 井上 尚樹, 藤田 雅之, 大東 延久, 朝熊 孝, 中尾 直也, 文 雅司, 陳 基忠, 綱脇 恵章, 南口 恵昭, 今崎 一夫, 山中 千代衛, 中井 貞雄

    日本物理学会講演概要集. 秋の分科会   1994 ( 4 )   209 - 209   1994.8

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  • USE OF MULTIPHOTON PHOTOELECTRIC PROCESS TO GENERATE A HIGH-BRIGHTNESS ELECTRON-BEAM FOR FREE-ELECTRON LASERS

    M ASAKAWA, K MIMA, S NAKAI, M FUJITA, K IMASAKI, C YAMANAKA

    APPLIED PHYSICS LETTERS   64 ( 16 )   2056 - 2058   1994.4

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    This letter describes a photocathode of tungsten driven by a frequency-doubled Nd:YAG laser. In this case, photoelectrons emerged by two-photon photoelectric process. The current density quadratically depended on the incident laser intensity, and the quantum yield then increased linearly with the laser intensity. Furthermore, by heating the cathode, we could improve the quantum yield. At a temperature around 1600-degrees-C, the peak current was measured to be 5.8 A with an irradiation of 3.2 MW, and then the quantum yield was to be 2.4 X 10(-6).

    DOI: 10.1063/1.111735

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  • 31a-YC-10 コンパクトRF加速器による自由電子レーザーの研究(III)

    上利 達雄, 浅川 誠, 酒本 直樹, 山本 達也, 井上 尚樹, 藤田 雅之, 大東 延久, 朝熊 孝, 陳 基忠, 綱脇 恵章, 今崎 一夫, 山中 千代衛, 中井 貞雄

    日本物理学会講演概要集. 年会   49 ( 4 )   244 - 244   1994.3

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  • 31a-YC-12 小型高輝度X線源の開発(I) : レーザーアンジュレータによる高調波X線の発生について

    陳 基忠, 藤田 雅之, 朝熊 孝, 今崎 一夫, 浅川 誠, 山本 達也, 酒本 直樹, 井上 尚樹, 上利 達雄, 梅本 理, 稗田 淳一, 大東 延久, 綱脇 恵章, 村井 昭, 三間 圀興, 中井 貞雄, 山中 千代衛

    日本物理学会講演概要集. 年会   49 ( 4 )   245 - 245   1994.3

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  • 31a-YC-13 小型高輝度軟X線光源の開発(II)

    朝熊 孝, 陳 基忠, 藤田 雅之, 今崎 一夫, 浅川 誠, 酒本 直樹, 山本 達也, 井上 尚樹, 上利 達雄, 大東 延久, 永見 樹義, 綱脇 恵章, 稗田 淳一, 梅本 理, 中井 貞雄

    日本物理学会講演概要集. 年会   49 ( 4 )   245 - 245   1994.3

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  • 31a-YC-5 Simulation of waveguide FEL oscillator using RF linac

    Goto M, Kuruma S, Mima K, Ohhigashi N, Asakawa M, Fujita M, Imasaki K, Yamanaka C, Nakai S

    Abstracts of the meeting of the Physical Society of Japan. Annual meeting   49 ( 4 )   241 - 241   1994.3

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  • 31a-YC-11 Research of Free Electron Laser with Compact RF linac(IV)

    Asakawa M, Sakamoto N, Inoue N, Agari T, Asakuma T, Fujita M, Chen J, Yamamoto T, Umemoto S, Hieda J, Ohigashi N, Tsunawaki Y, Imasaki K, Mima K, Yamanaka C, Nakai S

    Abstracts of the meeting of the Physical Society of Japan. Annual meeting   49 ( 4 )   244 - 244   1994.3

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  • 31a-YC-8 コンパクトRF加速器による自由電子レーザーの研究(I) : 総括

    藤田 雅之, 陳 基忠, 今崎 一夫, 古河 裕之, 車 信一郎, 山中 千代衛, 浅川 誠, 酒本 直樹, 山本 達也, 井上 尚樹, 三間 圀興, 中井 貞雄, 大東 延久, 朝熊 孝, 上利 達雄, 網脇 恵章, 永見 樹義, 梅本 理, 稗田 淳一

    日本物理学会講演概要集. 年会   49 ( 4 )   243 - 243   1994.3

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  • EXPERIMENTAL-STUDY OF A WAVE-GUIDE FREE-ELECTRON LASER USING THE COHERENT SYNCHROTRON-RADIATION EMITTED FROM ELECTRON BUNCHES

    M ASAKAWA, N SAKAMOTO, N INOUE, T YAMAMOTO, K MIMA, S NAKAI, JH CHEN, M FUJITA, K IMASAKI, C YAMANAKA, T AGARI, T ASAKUMA, N OHIGASHI, Y TSUNAWAKI

    APPLIED PHYSICS LETTERS   64 ( 13 )   1601 - 1603   1994.3

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    We have observed the oscillation of a waveguide mode free-electron laser using the coherent synchrotron radiation emitted from electron bunches. The oscillation was observed at 2.73 mm with a linewidth of 0.4%. This spectral selection was attributed to the dispersion of the radiation in the waveguide. We found that the oscillating radiation had to have the same group velocity as the velocity of the electrons passing through the wiggler field.

    DOI: 10.1063/1.111850

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  • A MILLIMETER-RANGE FEL EXPERIMENT USING COHERENT SYNCHROTRON-RADIATION EMITTED FROM ELECTRON BUNCHES

    M ASAKAWA, N SAKAMOTO, N INOUE, T YAMAMOTO, K MIMA, S NAKAI, J CHEN, M FUJITA, K IMASAKI, C YAMANAKA, T AGARI, T ASAKUMA, N OHIGASHI, Y TSUNAWAKI

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   341 ( 1-3 )   72 - 75   1994.3

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    We have observed radiation from a waveguide mode free electron laser using coherent synchrotron radiation emitted from electron bunches. The radiation was observed at 2.73 mm with a line-width of 0.4%. This spectral selection was attributed to the dispersion of the radiation in the waveguide. We found that the radiation had to have a group velocity equal to the velocity of the electrons passing through the wiggler field.

    DOI: 10.1016/0168-9002(94)90320-4

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  • 14a-N-5 Development of a Compact Laser Undulator X-Ray Source

    Abstracts of the meeting of the Physical Society of Japan. Sectional meeting   1993 ( 4 )   263 - 263   1993.9

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  • 14a-N-3 Research of Free Electron Laser with Compact RF linac (III)

    Sakamoto N., Asakawa M., Yamamoto T., Inoue N., Agari T., Asakuma T., Fujita M., Chen J., Ohigashi N., Tsunawaki Y., Imasaki K., Mima K., Yamanaka C., Nakai S.

    Abstracts of the meeting of the Physical Society of Japan. Sectional meeting   1993 ( 4 )   262 - 262   1993.9

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  • 14a-N-4 Research of Free Electron Laser with Compact RF linac (IV)

    Asakawa M., Sakamoto N., Inoue N., Agari T., Asakuma T., Fujita M., Chen J., Yamamoto N., Ohigashi N., Tsunawaki Y., Imasaki K., Mima K., Yamanaka C., Nakai S.

    Abstracts of the meeting of the Physical Society of Japan. Sectional meeting   1993 ( 4 )   262 - 262   1993.9

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  • 14a-N-2 コンパクトRFライナックによる自由電子レーザーの研究 (II) : 加速器動特性のシミュレーション

    山本 達也, 古河 裕之, 今崎 一夫, 藤田 雅之, 陳基忠, 浅川 誠, 酒本 直樹, 井上 尚樹, 上利 達雄, 朝熊 孝, 永見 樹義, 大東 延久, 綱脇 恵章, 三間 圀興, 中井 貞夫, 山中 千代衛

    日本物理学会講演概要集. 秋の分科会   1993 ( 4 )   261 - 261   1993.9

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  • 14a-N-1 コンパクト RF加速器による自由電子レーザーの研究 (I) : 総括

    藤田 雅之, 陳 基忠, 今崎 一夫, 山中 千代衛, 浅川 誠, 酒本 直樹, 山本 達也, 井上 尚樹, 三間 圀興, 中井 貞雄, 大東 延久, 朝熊 孝, 上利 達雄, 綱脇 恵章, 永見 樹義

    日本物理学会講演概要集. 秋の分科会   1993 ( 4 )   261 - 261   1993.9

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  • EXPERIMENTAL STUDIES OF PHOTOCATHODE MATERIALS FOR FELS

    M ASAKAWA, N SAKAMOTO, Y SHIMIZU, S NAKAI, K IMASAKI, C YAMANAKA

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   331 ( 1-3 )   302 - 306   1993.7

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    By using a photocathode, electrons can be generated in the narrow phase of the rf cycle of an rf gun with high peak current. We report experiments on metals and metal compounds to be used as photocathode materials.

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  • 31p-ZD-14 Research of Free Electron Laser with Compact RF linac

    Asakawa M., Sakamoto N., Inoue N., Esaki S., Murayama Y., Fujita M., Chen C., Aki T., Yamamoto T., Ohigashi N., Tsunawaki Y., Imasaki K., Yamanaka C., Nakai S.

    Abstracts of the meeting of the Physical Society of Japan. Annual meeting   48 ( 4 )   202 - 202   1993.3

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  • 31p-ZD-11 コンパクトRFライナックによる自由電子レーザーの研究(I) : 総括(プラズマ物理・核融合(自由電子レーザー))

    藤田 雅之, 今崎 一夫, 陳 基忠, 浅川 誠, 安芸 寿彦, 酒本 直樹, 山本 達也, 井上 尚樹, 村山 義文, 江崎 伸也, 大東 延久, 綱脇 恵章, 中井 貞雄, 山中 千代衛

    日本物理学会講演概要集. 年会   48 ( 4 )   200 - 200   1993.3

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  • 31p-ZD-13 コンパクトRFライナックによる自由電子レーザーの研究(III)(プラズマ物理・核融合(自由電子レーザー))

    山本 達也, 古河 裕之, 今崎 一夫, 藤田 雅之, 陳 基忠, 浅川 誠, 安芸 寿彦, 酒本 直樹, 井上 尚樹, 村山 義文, 江崎 伸也, 大東 延久, 綱脇 恵章, 中井 貞雄, 山中 千代衛

    日本物理学会講演概要集. 年会   48 ( 4 )   201 - 201   1993.3

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  • 31p-ZD-15 Research of Free Electron Laser with Compact RF linac

    Sakamoto N., Asakawa M., Inoue N., Esaki S., Murayama Y., Fujita M., Chen C., Aki T., Yamamoto T., Ohigashi N., Tsunawaki Y., Imasaki K., Yamanaka C., Nakai S.

    Abstracts of the meeting of the Physical Society of Japan. Annual meeting   48 ( 4 )   202 - 202   1993.3

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  • FEL Oscillation by Coherent Radiation Emitted from an Electron Bunch.

    ASAKAWA Makoto, SAKAMOTO Naoki, INOUE Naoki, ESAKI Sinya, YAMAMOTO Tatsuya, CHEN Jizhong, FUJITA Masayuki, IMASAKI Kazuo, OHIGASHI Nobuhisa, TSUNAWAKI Yoshiaki, NAKAI Sadao, YAMANAKA Chiyoe

    rle   21 ( 7 )   746 - 753   1993

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    The free-electron-laser experiment in the milli-meter-range by the coherent radiation emitted from an electron bunch is reported. With a 7MeV rf-linac, the spontaneous emission of 20W has been observed. The oscillation experiment has been performed by superimposing this radiation in the resonator. Power of 16W was observed at wavelength of 2.73mm.

    DOI: 10.2184/lsj.21.7_746

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  • 27a-A-11 高輝度電子ビームによる自由電子レーザーの研究 IV

    今崎 一夫, 浅川 誠, 安芸 寿彦, 酒本 直樹, 陳 基忠, 山本 達也, 大東 延久, 綱脇 恵章

    秋の分科会講演予稿集   1992 ( 4 )   261 - 261   1992.9

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  • 27a-A-12 Research of Free Electron Laser with High-Brightness Electron Beam

    Asakawa M, Sakamoto N, Inoue N, Murayama Y, Chen C, Aki T, Yamamoto T, Ohigashi N, Tunawaki Y, Imasaki K, Yamanaka C, Nakai S

    1992 ( 4 )   184 - 184   1992.9

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  • 27a-A-13 高輝度電子ビームによる自由電子レーザーの研究(IV)

    安芸 寿彦, 浅川 誠, 酒本 直樹, 山本 達也, 大東 延久, 綱脇 恵章, 今崎 一夫, 山中 千代衛, 中井 貞雄

    秋の分科会講演予稿集   1992 ( 4 )   184 - 184   1992.9

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  • HIGHER HARMONIC-GENERATION IN A MODIFIED WIGGLER MAGNETIC-FIELD

    M ASAKAWA, K MIMA, S NAKAI, K IMASAKI, C YAMANAKA

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   318 ( 1-3 )   538 - 545   1992.7

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    Analysis is performed for higher harmonic generation on a modified wiggler.

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  • 27p-D-9 DEVELOPMENT OF HIGH BRIGHTNESS ELCTRON BEAM FOR FREE ELECTRON LASER

    Asakawa M., Aki T., Imasaki K., Yamanaka C., Nakai S.

    1991 ( 4 )   190 - 190   1991.3

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Awards

  • レーザー学会 レーザー研究進歩賞

    1995  

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    Country:Japan

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Research Projects

  • 自由電子レーザーの研究

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    Grant type:Competitive

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  • Study on Free-Electron Lasers

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Devising educational methods

  • 「物理学を学ぶ(力学1)」及び「量子光工学」においては,(1)現象を想像すること,(2)想像したものを数式で表現する技術,そして(3)数式を計算する技術,を区別して扱うことを徹底した.「現象を想像すること」がどういうことなのか具体的に示すために,コンピュータシミュレーションによるアニメーションを提示した.授業評価アンケートの結果を鑑みると,これら一連の講義方法により学生の理解を深めることができたと考えることができる.  「物理数学C」は難解な複素関数論を扱うものであるが,種々の定理が理学的に工学的にどのように応用されるのかを示しながら講義を進めた.定理の証明に終始しなければ,多くの学生の興味をひくことができるようである.  実験系科目では,ガイドブックに掲載した実験のみならず,用意した実験装置を使って学生独自のアイデアに基づいた実験も行った.このような経験が楽しかったという学生が多数いた.

Teaching materials

  • 物理学・応用物理学基礎実験ガイドブック, 共著, 2008年3月, 浅川誠, 藤井和成, 山本健, 学術図書出版 物理・応用物理学科2年生を対象とした実験授業用のガイドブック.力学,光学から電子工学にわたる広範な分野の基礎的な現象について,その原理を解説するとともに,実験手順を示した.

Teaching method presentations

  •  特になし

Special notes on other educational activities

  • 「物理の教育」では,高校の物理教員と協力し複数担任の形で講義を行い,特に高校の教科書に掲載されている様々な物理学現象を実験し,それを通して学生に教材開発能力の素養を与えた.  小中高生対象のサイエンスセミナーにおいて光の物理学に関するテーマでセミナーを開講した.教材開発,テキスト作成をした.