Tihiro Ohkawa

Summary

Tihiro Ohkawa (Japanese: 大河千弘, Hepburn: Ōkawa Chihiro, January 3, 1928 - September 27, 2014)[1][2] was a Japanese physicist whose field of work was in plasma physics and fusion power. He was a pioneer in developing ways to generate electricity by nuclear fusion when he worked at General Atomics.[3] Ohkawa died September 27, 2014, in La Jolla, California, at the age of 86.[3]

Tihiro Ohkawa
Born(1928-01-03)January 3, 1928
DiedSeptember 27, 2014(2014-09-27) (aged 86)
Alma materUniversity of Tokyo
AwardsJames Clerk Maxwell Prize for Plasma Physics (1979)
Scientific career
FieldsPlasma Physics

Early life and career edit

Ohkawa was born in Kanazawa on January 3, 1928.[4][5] He studied physics at the University of Tokyo in 1950, and was a member of the Yoshio Nishina group for researching cosmic altitude radiation for 16 years even during the World War II.[4] He was a researcher at CERN and at Midwestern State University before becoming a professor at the University of Tokyo. In 1960, he went to General Atomics, where he led a fusion research project and later became vice president and deputy chairman of the board.

In 1994, Ohkawa left General Atomics to found TOYO Technologies. In 2004, he was co-founder of Nano Fusion Technologies with Masano Nishikawa for the development of microfluidics. He was also a physics professor at the University of California, San Diego.

Scientific contributions edit

In 1955, Ohkawa independently came up with idea of the fixed-field alternating gradient accelerator (FFAG) together with Keith Symon and Andrei Kolomensky, which led to the development of the first prototype in 1956 by the Midwestern Universities Research Association (MURA). He then developed a procedure to stabilize instabilities in tokamaks using multipole magnetic fields with Donald Kerst in 1960,[6] which was then later confirmed by experiments.[7]

In 1968, Ohkawa demonstrated that the plasma-current multipole configuration used to trap plasmas was stable,[8] which resulted in the development of a series of tokamaks with vertically elongated plasma cross sections called the doublet.[4][9] This eventually led to General Atomics' DIII-D tokamak, which influenced the design and concept of ITER.[10]

Ohkawa was also involved in the use of radioactive isotopes in the separation of nuclear isotopes from nuclear waste (at the Archimedes Technology Group in San Diego, which he founded).[11]

Ohkawa holds over 50 patents, in areas such as tile accelerators, fusion technology and biotechnology.[12]

Honors and awards edit

In 1968, Ohkawa became a Fellow of the American Physical Society.[13] In 1979, he received the James Clerk Maxwell Prize for Plasma Physics for "his development of multi-current or doublet approach to the design of tokamaks with non-circular cross sections and for investigation of plasma confinement in toroidal multipoles".[14]

He also received the 1984 Fusion Power Associates Leadership Award.[15]

References edit

  1. ^ Amemiya, Takahisa (2009). 大河千弘と核融合研究 (PDF) (in Japanese). Nihon University. Retrieved 8 September 2018.
  2. ^ "Tihiro Ohkawa". www.aip.org. 2015-03-16. Retrieved 2020-02-25.
  3. ^ a b Robbins, Gary. "Renowned physicist Ohkawa dies at 86". The San Diego Union-Tribune. Retrieved 2018-09-08.
  4. ^ a b c Maisel, Merry (2014-10-29). "Tihiro Ohkawa". Physics Today. doi:10.1063/pt.5.6106.
  5. ^ 日本人名大辞典+Plus, デジタル版. "大河千弘(おおかわ ちひろ)とは". コトバンク (in Japanese). Retrieved 2020-02-24.
  6. ^ Ohkawa, T.; Kerst, D. W. (1961). "Stable Plasma Confinement by Multipole Fields". Physical Review Letters. 7 (2): 41–42. Bibcode:1961PhRvL...7...41O. doi:10.1103/physrevlett.7.41. ISSN 0031-9007.
  7. ^ Ohkawa, T.; Yoshikawa, M.; Kribel, R. E.; Schupp, A. A.; Jensen, T. H. (1970). "Plasma Confinement in dc Octopole". Physical Review Letters. 24 (3): 95–98. Bibcode:1970PhRvL..24...95O. doi:10.1103/physrevlett.24.95. ISSN 0031-9007.
  8. ^ Ohkawa, T.; Voorhies, H. G. (1969). "Plasma-Current Multipole Experiments". Physical Review Letters. 22 (24): 1275–1277. Bibcode:1969PhRvL..22.1275O. doi:10.1103/physrevlett.22.1275. ISSN 0031-9007.
  9. ^ Meade, Dale (2009). "50 years of fusion research". Nuclear Fusion. 50 (1): 014004. doi:10.1088/0029-5515/50/1/014004. ISSN 0029-5515. S2CID 17802364.
  10. ^ "diii-d:home [MFE: DIII-D and Theory]". fusion.gat.com. Retrieved 2020-02-24.
  11. ^ Cluggish, B.P.; Ohkawa, T.; Agnew, S.F.; Freeman, R.L.; Miller, R.L.; Putvinski, S.; Sevier, L.; Umstadter, K.R. (2001). "Separation of radionuclides from nuclear waste by a plasma mass filter". IEEE Conference Record - Abstracts. PPPS-2001 Pulsed Power Plasma Science 2001. 28th IEEE International Conference on Plasma Science and 13th IEEE International Pulsed Power Conference (Cat. No.01CH37255). IEEE. p. 323. doi:10.1109/ppps.2001.961000. ISBN 0-7803-7141-0.
  12. ^ "FPA Program Notes". aries.ucsd.edu. Retrieved 2020-02-24.
  13. ^ "APS Fellow Archive". www.aps.org. Retrieved 2020-02-24.
  14. ^ "1979 James Clerk Maxwell Prize for Plasma Physics Recipient". American Physical Society. Retrieved 2020-02-24.
  15. ^ "FPA Awards". fusionpower.org. Retrieved 2020-02-24.

External links edit

  • Fusion Pioneer Tihiro Ohkawa Dies from General Atomics website
  • Oral history interview transcript with Tihiro Ohkawa on 23 May 2006, American Institute of Physics, Niels Bohr Library & Archives