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Researcher Information

last modified:2023/06/06

Professor YOKOYAMA Akihiko


Faculty, Affiliation

Faculty of Chemistry, Institute of Science and Engineering radiochemistry

College and School Educational Field

Division of Material Chemistry, Graduate School of Natural Science and Technology
Division of Material Chemistry, Graduate School of Natural Science and Technology
Course in Chemistry, School of Chemistry, College of Science and Engineering
School of Chemistry, College of Science and Engineering


Radiochemistry Laboratory TEL:076-264-6127 FAX:076-264-5742

Academic Background

【Academic background(Doctoral/Master's Degree)】
Osaka University Doctor Graduate School, Division of Natural Science 1988
【Academic background(Bachelor's Degree)】
Osaka University 198203


Osaka University Graduate School of Science(1990/04/01-2001/04/30)
Oregon State University, USA Department of Chemistry(1988/09/01-1990/03/31)

Year & Month of Birth


Academic Society



nuclear chemistry、Inorganic chemistry、Nuclear engineering、Bio-related chemistry

Speciality Keywords

Generator for nuclear medicine,Nuclear reaction with heavy elements,nuclear chemistry

Research Themes

Production of Np isotopes for standard material in accelerator mass spectrometry

Production of Np isotopes for standard material in accelerator mass spectrometry
Determination of Np-237, an isotope of minor-actinide Np, which is slightly present in the environment due to the release from nuclear facilities, is useful in various earth science fields such as surface material circulation, environmental pollution assessment and so on. The measurement of Np-237 is expected to be quantified by accelerator mass spectrometry (AMS), although an internal standard method for Np needs an appropriate spike. Tracers for several elements are available now but the spike for neptunium has not been developed yet. We aim to devise an efficient method for the production of Np-236 in the ground state of half-life 1.54×10^5 y as a candidate for the spike nuclide.

Chemistry of Astatine for Isotope Therapy

Chemistry of Astatine for Isotope Therapy The short path length and high linear energy transfer of alpha particles are expected to enable targeted alpha therapy for the treatment of tumor. A promising nuclide among various alpha emitters is At-211 with a half-life of 7.21 h. To improve the availability of 211At, the development of a Rn-211/At-211 generator would be useful for expanding nuclide production away from accelerator facilities because Rn-211, which has a half-life of 14.6 h, is the parent nuclide of At-211. Handling of Rn and chemistry of At have not been established, yet. We are developing the techniques on these themes.

Chemical properties of heavy elements

Chemical properties of heavy elements

Study on the mechanims of heavy-ion nuclear reactions

Study on the mechanims of heavy-ion nuclear reactions

Angular momentum dependence of heavy-ion induced reaction



  •  Behavior of Pionic Hydrogen Atoms in Gas and Liquid Phases J. Radioanal. Nucl. Chem. 239 1 169-173 1999/01
  •  Behavior of Pionic Hydrogen Atoms in Liquid Organic Compounds Hyp. Int. 106 1-4 301-306 1997
  •  Charge Degree of Freedom as a Sensitive Probe for Fission Mechanism J. Radioanal. Nucl. Chem. 223 1-2 99-119 1997/02
  •  Determination of the Formation Cross Section by γ Spectrometry : Derivation of Universal Correction Formulas for Ingrowth during Irradiation Nucl. Instr. and Meth. in Phys. Res. A 416 2-3 301-313 1998/11
  •  Different Crystal Chemistries of the 117Cd→117In and 111mCd→111Cd Probes in LiNbO3 and LiTaO3 Studied by Time-Differential Perturbed-Angular-Correlation Technique Phys. Rev. B 60 17 11963-11970 1999/11

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  •  Fast Fission Mechanism and Duality of the Diffusion Process Eur. Phys. J. A 3 3 281-292 1998/11
  •  Fission Fragment Configurations at the Scission Point of 233U, 235U and 239Pu(nth,f) J. Radioanal. Nucl. Chem. 239 1 117-122 1999/01
  •  Fission Mechanisms in the Carbon-Induced Fission of Uranium J. Alloys and Compounds 271-273 322-326 1998/06
  •  Intensity Patterns of Pionic X Rays Emitted from Some Organic Compounds Radiochimica. Acta. 80 1 31-36 1998/01
  •  Mechanism of the ferroelectric phase transitions in LiNbO3 and LiTaO3 Phys. Rev. B 65 5 052107-1-4 2002/02
  •  Negative Pion Transfer Process in a Hydrogen-Containing Gas Mixture J. Radioanal. Nucl. Chem. 239 1 159-163 1999/01
  •  Pion transfer processes of pionic atoms in the gas mixtures containing hydrogen at various pressures Radiochim. Acta 89 11-12 849-853 2001/12
  •  Radiochemical Study of Fast Fission Mechanism J. Radioanal. Nucl. Chem. 239 1 103-108 1999/01
  •  Radiochemical study on the mechanism of target fragmentation of Cu, Nb, Pr and Au targets induced by 12C and 40Ar projectiles Radiochim. Acta 89 11-12 703-706 2001/12
  •  Reaction Mechanism for Target-Like Products from 197Au Target Bombarded with 12C Ions of Energies above 100 MeV/u J. Radioanal. Nucl. Chem. 239 1 143-149 1999/01
  •  Role of Effective Distance in the Fission Mechanism Study by the Double-Energy Measurement for Uranium Isotopes J. Nucl. Sci. Tech. 34 9 871-881 1997/09
  •  Specific Fission J-Window and Angular Momentum Dependence of the Fission Barrier J. Phys. Soc. Jpn. 66 4 998-1009 1997/04
  •  Startup of transactinide chemistry in JAERI Radiochim. Acta 89 11-12 733-736 2001/12
  •  Sudden Changes in the Characteristics of GDR Fission of 238U around the Critical Energy for Nuclear Phase Transition Radiochimica. Acta. 80 4 171-179 1998/04
  •  Formation cross sections of the products from target fragmentation of Nb, Pr and Au induced by 12C and 40Ar projectiles HIMACにおける核反応断面積の測定と検出器の研究 HIMAC-042 95-99 2001/10
  •  Radiosiotope production in target fragmentation with high-energy heavy-ions at HIMAC CZECHOSLOVAK JOURNAL OF PHYSICS 53 411-416 2003
  •  Ultra-sensitive detection of p-process nuclide 146Sm produced by (gamma, n), (p, 2ne) and (n, 2n) reactions N Kinoshita, T Hashimoto, T Nakanishi, A Yokoyama, H Amakawa, T Mitsugashira, T Ohtsuki, N Takahashi, I Ahmad, J P Greene, D J Henderson, C L Jiang, M Notani, R C Pardo, N Patel, K E Rehm, R Scott, R Vondrasek, L Jisonna, P Collon, D Robertson, C Schmitt, X D Tang, Y Kashiv, H Nassar and M Paul JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS 35 1 0140331-0140337 2008/01
  •  Incorporation Rate Measurements of 10Be, 230Th, 231Pa and 239,240Pu Radionuclides in Manganese Crust in the Pacific Ocean: A Search for Extraterrential Material Norikazu Kinoshita, Yuko Sato, Takeyasu Yamagata, Hisao Nagai, Akihiko Yokoyama and Takashi Nakanishi 63 5 813-820 2007/09
  •  Measurement of electric field gradient at 117In on the Cu-site in mavicyanin by perturbed angular correlation of gamma-rays A. Yokoyama, T. Hashimoto, K. Ihara, H. Kikunaga, N. Kinoshita, I. Yamazaki, K. Kataoka, M. Yanase, Takata, Y. Murakami, K. Takamiya, M. Tanigaki and Y. Ohkubo HYPERFINE INTERACTIONS 181 69-73 2008/08
  •  Development of a rapid source preparation method for high-resolution α-particle spectrometry H. Kikunaga, Y. Kasamatsu, K. Takamiya, T. Ohtsuki, H. Yuki, A. Yokoyama, T. Nakanishi, T. Mitsugashira APPLIED RADIATION AND ISOTOPES 67 539-543 2008/11
  •  Half-life estimation of the first excited state of 229Th by using α-particle spectrometry H. Kikunaga, Y. Kasamatsu, H. Haba, T. Mitsugashira, M. Hara, K. Takamiya, T. Ohtsuki, H. Yuki, A. Yokoyama, T. Nakanishi, A. Shinohara PHYSICAL REVIEW C 80 034315 2009/09
  •  Anionic Fluoro Complex of Element 105, Db Y. Kasamatsu, Atsushi Toyoshima, Masato Asai, Kazuaki Tsukada, Zijie Li, Yasuo Ishii, Hayato Toume, Tetsuya K. Sato, Takahiro Kikuchi, Ichiro Nishinaka, Yuichiro Nagame, Hiromitsu Haba, Hidetoshi Kikunaga, Yuki Kudou, Yasuji Oura, Kazuhiko Akiyama, Wataru Sato, Kazuhiro Ooe, Hiroyuki Fujisawa, Atsushi Shinohara, Shin-ichi Goto, Taichi Hasegawa, Hisaaki Kudo, Tomohiro Nanri, Mikio Araki, Norikazu Kinoshita, Akihiko Yokoyama, Fangli Fan, Zhi Qin, Christoph E. Düllmann, Matthias Schädel and Jens V. Kratz CHEMISTRY LETTERS  38 11 1084-1085 2009/11
  •  Adsorption of Db and its homologues Nb and Ta, and the pseudo-homologue Pa on anion-exchange resin in HF solution K. Tsukada, H. Haba, M. Asai, A. Toyoshima, K. Akiyama, Y. Kasamatsu, I. Nishinaka, S. Ichikawa, K. Yasuda, Y. Miyamoto, K. Hashimoto, Y. Nagame, S. Goto, H. Kudo, W. Sato, A. Shinohara, Y. Oura, K. Sueki, H. Kikunaga, N. Kinoshita, A. Yokoyama, M. Schädel, W. Brüchle, and J. V. Kratz RADIOCHIMICA ACTA 97 83-89  2009/02
  •  Improvements on the method for determining of 210Pb and 210Po in lead Masaki Uesugi, Masayasu Noguchi, Akihiko Yokoyama, and Takashi Nakanishi JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY 283 577–584  2010/01
  •  Anthropogenic Pu distribution in Tropical East Pacific, Science of the Total Environment Norikazu Kinoshita, Takahiro Sumi, Kiyotaka Takimoto, Mika Nagaoka, Akihiko Yokoyama, Takashi Nakanishi SCIENCE OF THE TOTAL ENVIRONMENT  409 10 1889-1899 2011/10
  •  Distribution of elements in the area contaminated with radioactivities 16 7-24 2013
  •  Studies on temporal change in depth profiles of the Rn concentrations in natural water columns N. Yamada, M. Uesugi, A. Yokoyama, T. Nakanishi J. Radioanal. Nucl. Chem. 299 1177-1182 2014
  •  Development of a new continuous dissolution apparatus with a hydrophobic membrane for superheavy element chemistry K. Ooe, M. F. Attallah, M. Asai, N. Goto, N. S. Gupta, H. Haba, M. Huang, J. Kanaya, Y. Kaneya, Y. Kasamatsu, Y. Kitatsuji, Y. Kitayama, K. Koga, Y. Komori, T. Koyama, J. V. Kratz, H. V. Lerum, S. Miyashita, Y. Oshimi, V. Pershina, D. Sato, T. K. Sato, Y. Shigekawa, A. Shinohara, A. Tanaka, A. Toyoshima, K. Tsukada, S. Tsuto, T. Yokokita, A. Yokoyama, J. P. Omtvedt, Y. Nagame, M. Schädel J. Radioanal. Nucl. Chem.  303 2 1317-1320  2015
  •  The situation of Ag and Pu radioisotopes in soil released from Fukushima Daiichi nuclear power plants H. Kimura, M. Uesugi, A. Muneda, R. Watanabe, A. Yokoyama, T. Nakanishi  J. Radioanal. Nucl. Chem.  303 2 1469–1471  2015
  •  traction of astatine isotopes for development of radiopharmaceuticals using a 211Rn–211At generator E. Maeda, A. Yokoyama, T. Taniguchi, K. Washiyama, I. Nishinaka J. Radioanal. Nucl. Chem. 303 2 1465-1468 2015
  •  Chemical studies of Mo and W in preparation of a seaborgium (Sg) reduction experiment using MDG, FEC, and SISAK A. Toyoshima • K. Ooe, S. Miyashita, M. Asai, M. F. Attallah, N. Goto, N. S. Gupta , H. Haba , M. Huang, J. Kanaya, Y. Kaneya, Y. Kasamatsu, Y. Kitatsuji, Y. Kitayama, K. Koga , Y. Komori , T. Koyama, J. V. Kratz, H. V. Lerum, Y. Oshimi, V. Pershina, D. Sato, T. K. Sato , Y. Shigekawa, A. Shinohara, A. Tanaka, K. Tsukada, S. Tsuto, T. Yokokita, A. Yokoyama, J. P. Omtvedt, Y. Nagame, M. Schädel,  J. Radioanal. Nucl. Chem.  303 2 1169–1173  2015
  •  Production and separation of astatine isotopes in the 7Li + natPb reaction I. Nishinaka, A. Yokoyama, K. Washiyama, E. Maeda, S. Watanabe, K. Hashimoto, N. S. Ishioka, H. Makii, A. Toyoshima, N. Yamada and R. Amano,  J. Radioanal. Nucl. Chem.  304 3 1077–1083  2015
  •  Proton capture cross sections on neutron-magic 144Sm at astrophysically relevant energies Phys. Rev. C 93 025801-1-9  2016
  •  Study on a Determination Method of Radioactive Antimony in Soil near Fukushima Nuclear Power Plant Naoki Miyazawa, Masaki Uesugi, Akihiko Yokoyama Proceedings of the 19th Workshop on Environmental Radioactivity 2018-7 61 2018
  •  Dissolved State of Radon with Cluster Molecules of Solvent Yamada, N., Shin, Y., Kawasaki, K., Yokoyama, A., Ida, T. J. Radioanal. Nucl. Chem. 318 2303 2018/10/03
  •  Measurements of the excitation functions of radon and astatine isotopes from 7Li-induced reactions with 209Bi for development of a 211Rn–211At generator Eita Maeda, Akihiko Yokoyama, Takumi Taniguchi, Kohshin Washiyama, Ichiro Nishinaka J. Radioanal. Nucl. Chem. 323 921-926 2020
  •  Extraction behavior of rutherfordium as a cationic fluoride complex with a TTA chelate extractant from HF/HNO3 acidic solutions Akihiko Yokoyama, Yuta Kitayama, Yoshiki Fukuda, Hidetoshi Kikunaga, Masashi Murakami,Yukiko Komori, Shinya Yano, Hiromitsu Haba, Kazuaki Tsukada, Atsushi Toyoshima Radiochimca Acta 107 1 27 2019/01/01
  •  Rapid separation method for protactinium from uranium using manganese oxide filter cake Hiroki Nakada, Akihiko Yokoyama Sci. Rep. Kanazawa Univ. 63 59 2019
  •  Mechanisms of the Solid Cancer Induced by Atomic Bomb and the Spontaneous Cancer in the Daily Life-Proposal of a New Medical Treatment for Cancers Hiroshi Baba, Akihiko Yokoyama Clinical Research & Bioethics 14 2 1000455 2023
  •  Relative formation probabilities for fluoride and oxyfluoride anions of U, Np, Pu and Am in accelerator mass spectrometry measurements at VERA A. Wiederin, M. Kern, K. Hain, M. Martschini, A. Sakaguchi, P. Steier, A. Yokoyama, R. Golser Nclear Instruments and Methods in Physics Research B 528 40-44 2022
  •  Preparation of a carrier free 124Sb tracer produced in the Sn(p,n)reaction Naoki Miyazawa,Masaki Uesugi, and Akihiko Yokoyama Radiochim. Acta 109 6 453 2021

Conference Presentations

  • Decontamination of Po in the 211Rn/211At generator system(conference:Pacifichem 2021)(2021/12/19)
  • Production of a Np standard material for accelerator mass spectrometry in nuclear reactions (conference:18th Radiochemical conference)(2018/05/13)
  • Dissolved state of radon with cluster molecules of solvent(conference:18th Radiochemical conference )(2018/05/13)


  •  A research project on chemical properties of the heavy actinide and trans-actinide elements CNS-REP-42 303-312 2001/12

Arts and Fieldwork


Theme to the desired joint research

Grant-in-Aid for Scientific Research


Competitive research funding,Contribution

Collaborative research,Consignment study

Classes (Bachelors)

○Lecture on Life in Campus and Society(2021)
○Specialized Topics in Chemistry(2021)
○Experiments in Basic Chemistry B(2021)
○Radiochemistry I(2021)
○Specialized Topics in Chemistry(2018)
○Experiments in Basic Chemistry B(2018)
○International Training B(2018)
○World of Chemistry(2018)
○Radiochemistry I(2018)
○International Training A(2018)
○Experiments in Basic Chemistry B(2017)
○Radiochemistry I(2017)
○World of Chemistry(2017)
○Fundamentals of Physical Chemistry(2017)
○World of Chemistry(2016)
○Experiments in Basic Chemistry B(2016)
○Radiochemistry I(2016)
○Experiments in Fundamental Chemistry(2016)

Classes (Graduate Schools)

○Nuclear and Radiochemistry(2021)
○Radiohemistry for Education(2021)
○Topics in Chemistry(2021)
○Material Analysis Chemistry III(2021)
○Seminar in Material Analysis(2021)
○Material Analysis Chemistry III(2018)
○Nuclear Chemistry of Heavy Elements(2018)
○Nuclear and Radiochemistry(2018)
○Topics in Chemistry(2018)
○Seminar in Material Analysis(2018)
○Material Analysis Chemistry III(2017)
○Topics in Chemistry(2017)
○Topics in Chemistry(2017)
○Seminar in Material Analysis(2017)
○Nuclear Chemistry of Heavy Elements(2017)
○Topics in Chemistry(2016)
○Material Analysis Chemistry III(2016)
○Nuclear and Radiochemistry(2016)
○Seminar in Material Analysis(2016)
○Advanced Material Chemistry(2016)
○Nuclear Chemistry of Heavy Elements(2016)
○Seminar in Material Analysis(2016)
○Topics in Chemistry(2016)

International Project

International Students

Lecture themes

Others (Social Activities)

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