• Yongkyoon In (인용균)

  • Professor
  • Fusion Plasma Physics Research
  • Current Research Interests

    3-D Magnetic field Physics

    The presence of 3-D magnetic field (strictly speaking, non-axisymmetric magnetic field) brings both challenges and opportunities in fusion plasmas. Specifically, the plasma stability and transport, as well as turbulence, are greatly affected by the 3-D magnetic field. Among various 3-D physics themes, the resonant magnetic perturbation (RMP)-driven, edge-localized-modes (ELM) control has been one of the hottest topics scientifically and technologically.

    Considering that ELMs in magnetically confined plasmas would outburst substantial heat and particle fluxes on the divertor and plasma facing components, the full ELM-crash- suppression would help us avoid such harmful damages, so that almost all the major fusion devices have been vigorously searching for a solution. In this regard, as of 2018, the Korea Superconducting Tokamak Advanced Research (KSTAR) located at Daejeon, Korea became the world no. 1 device, in that the longest sustainment (~34 sec) of full ELM-crash- suppression has been demonstrated using n=1 RMP (where n refers to the toroidal mode number).

    Nonetheless, the detailed physics mechanism to make full ELM-crash- suppression, instead of ELM-crash- mitigation, remains to be clarified, whereas several key physics parameters, such as edge safety factor (q95), collisionality (nu*), and shape effect, have been found. Since the RMP configurations to be installed in ITER (the largest tokamak being built in Southern France, whose size is expected to be comparable to that of future fusion reactor) would be similarly tested in KSTAR, the divertor heat flux profiles and their dependence on 3-D field configurations are being actively investigated.

    Currently, such 3-D field physics study plays a role of hub in drawing the attentions of both theoretical and experimental gurus, whose accomplishments would likely be remembered as one of the significant contributions to fusion research forever.

    Magnetohydrodynamics/Error Field Study/Neutral Particle Diagnostic Development would belong to the main research interests, as well.

  • Biographical Sketch
    • Professor, UNIST (2018 — Present)
    • Principal Scientist/Special Scientist (2013 – 2018) with National Fusion Research Institute (NFRI) at KSTAR
    • Senior Staff Scientist/Staff Scientist (2004 -2013) with FAR-TECH, Inc at DIII-D
    • Research Scientist (2000 – 2002) with Univ. of Idaho at Plasma Science and Fusion Center, MIT at Alcator C-Mod
      PhD (2000), Applied Plasma Physics, Nuclear Engineering
    • Massachusetts Institute of Technology (MIT)
      M.S. (1995) Nuclear Engineering,
    • Seoul National University (SNU)
      B.S. (1990) Nuclear Engineering,(Magna cum laude)
    • Seoul National University (SNU)
  • Selected Publications
    • Y. In, J.-K. Park, Y.M. Jeon, J. Kim, G.Y. Park, J.-W. Ahn, A. Loarte, W.H. Ko, H.H. Lee, J.W. Yoo, J.W. Juhn, S.W. Yoon, H. Park, and 3D Physics Task Force in KSTAR, “Enhanced understanding of non‐axisymmetric intrinsic and controlled field impacts in tokamaks”, Nucl. Fusion 57, 116054 (2017)
    • Y. In, J.K. Park, J.M. Jeon, J. Kim and M. Okabayashi, “Extremely low intrinsic error field in KSTAR and its implications”, Nucl. Fusion 55, 043004 (2015)
    • Y. In, M S Chu, G L Jackson, J S Kim, R J La Haye, Y Q Liu, L Marrelli, M Okabayashi, H Reimerdes and E J Strait, “Requirements for active resistive wall mode (RWM) feedback control,” Plasma Phys. Control. Fusion 52, 104004 (2010)
    • Y. In, I.N. Bogatu, A.M. Garofalo, G.L. Jackson, J.S. Kim, R.J. La Haye, M.J. Lanctot, L. Marrelli, P. Martin, M. Okabayashi, H. Reimerdes, M.J. Schaffer and E.J. Strait, “On the roles of direct feedback and error field correction in stabilizing resistive-wall modes,” Nucl. Fusion 50, 042001 (2010)
    • Y. In, J. Kim, J.S. Kim, A. M. Garofalo, G. L. Jackson, R. J. La Haye, E. J. Strait, M. Okabayashi, and H. Reimerdes,  “Influences of multiple low-n modes on n=1 resistive wall mode (RWM) identification and feedback control” Phys. Plasmas 15, 102506 (2008)
    • Y. In, J. S. Kim, D. H. Edgell, E. J. Strait, D. A. Humphreys, M. L. Walker, G. L. Jackson, M. S. Chu, R. Johnson, R. J. La Haye, M. Okabayashi, A. M. Garofalo and H. Reimerdes, Model-based dynamic resistive-wall- mode (RWM) identification and feedback control in the DIII-D tokamak, Phys. Plasmas 13, 062512 (2006)
    • Y. In, A.E. Hubbard, I.H. Hutchinson, Electron Cyclotron Emission Refraction Effects during Edge-localized Modes, Plasma Phys. Control. Fusion 43, 645 (2001)
    • Y. In, J.J. Ramos, R.J. Hastie, P.J. Catto, A.E. Hubbard, I.H. Hutchinson, E. Marmar, M. Porkolab, J. Snipes, S. Wolfe, G. Taylor, and A. Bondeson., Identification of Mercier Instabilities in Alcator C-Mod tokamak, Phys. Plasmas 7, 5087 (2000)
    • Y. In, J.J. Ramos, A.E. Hubbard, I.H. Hutchinson, M. Porkolab, J. Snipes, S.M. Wolfe, and A. Bondeson, Resistive n=1 modes in reversed magnetic shear Alcator C-Mod plasmas, Nucl. Fusion 40, 1463 (2000)