Comment on ‘Numerical modeling of tokamak breakdown phase driven by pure Ohmic heating under ideal conditions’

Yoo, Mingoo ; Na, Yong-Su
Issue date: 2019
Rights:
Creative Commons Attribution 4.0 International (CC BY)
Cite as:
Yoo, Mingoo & Na, Yong-Su. Comment on ‘Numerical modeling of tokamak breakdown phase driven by pure Ohmic heating under ideal conditions’ [Data set]. Princeton Plasma Physics Laboratory, Princeton University. https://doi.org/10.11578/1562104
@electronic{yoo_mingoo_unknown,
  author      = {Yoo, Mingoo and
                Na, Yong-Su},
  title       = {{Comment on ‘Numerical modeling of tokama
                k breakdown phase driven by pure Ohmic h
                eating under ideal conditions’}},
  publisher   = {{Princeton Plasma Physics Laboratory, Pri
                nceton University}},
  url         = {https://doi.org/10.11578/1562104}
}
Description:

In this comment, we point out possible critical numerical flaws of recent particle simulation studies (Jiang et al 2016 Nucl. Fusion 56 126017, Peng et al 2018 Nucl. Fusion 58 026007) on the electrical gas breakdown in a simple one-dimensional periodic slab geometry. We show that their observations on the effects of the ambipolar electric fields during the breakdown, such as the sudden reversal of the ion flow direction, could not be real physical phenomena but resulting from numerical artifacts violating the momentum conservation law. We show that an incomplete implementation of the direct-implicit scheme can cause the artificial electric fields and plasma transports resulting in fallacies in simulation results. We also discuss that their simple plasma model without considering poloidal magnetic fields seriously mislead the physical mechanism of the electrical gas breakdown because it cannot reflect important dominant plasma dynamics in the poloidal plane (Yoo et al 2018 Nat. Commun. 9 3523).

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1 README.txt 956 Bytes
2 ARK_DATA.zip 457 KB