Plasma and Fusion Research

Volume 15, 1405019 (2020)

Regular Articles

An Audit of Occurrence of Dust in Tokamak and Stability of Fusion Plasma
Ayan Kumar MAKAR
Centre of Plasma Physics, Institute of Plasma Research, Sonapur, Assam 782402, India
(Received 17 October 2019 / Accepted 2 March 2020 / Published 14 April 2020)

Abstract

Proliferation of dusty layers inside the Tokamak prompts deleterious effect in Tokamak operation. The stability of the fusion plasma is adversely affected by building-up of dusty layers inside the tokamak which actuate disruptions in tokamak's performance. The current study is based on probing the mechanisms of dust accumulation inside the Tokamak device by simulating the process with the support of pulsed plasma accelerator. Experimentally it was observed that upon interacting with the pulsed power plasma stream, the materials used for designing the in-vessel elements of Tokamak such as graphite, lost its crystalline structure which in turn affects its inherent properties like ductility, malleability, rust resistance etc., thus emanation of dust paricles take place as a result of collisions between plasma species such as electrons, ions and neutrals with molecules of graphite as the tokamak material, ergo causing erosion in the tokamak material. The concatenated dusty layers formed due to accumulation of dust particles inside the Tokamak can cause probable instability in fusion plasma that would mar the function of the Tokamak device, besides the generated dust would become chemically reactive, radioactive or toxic. The dynamics of dust grains can be realised by Coulomb force, ion drag force, frictional forces on ions, ion pre-sheath drifts etc. and can also be interpreted from the kinetic theory of dusty plasma, to account this the numerical studies have been carried out with DUSTT and UEDGE codes to understand the dust dynamics and transport mechanisms.

Keywords

Tokamak, fusion plasma, dusty plasma, stability, DUSTT, UEDGE, radioactive, erosion

DOI: 10.1585/pfr.15.1405019

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References

  • [1] V.N. Tsytovich, Phys. Uspekhi 40, 53 (1997).
  • [2] J. Winter, Plasma Phys. Control. Fusion 40, 1201 (1998).
  • [3] J. Winter, Phys. Plasmas 7, 3862 (2000).
  • [4] S. Banerjee et al., Plasma Phys. Control. Fusion 60, 095001 (2018).
  • [5] G. Federici et al., J. Nucl. Mater. 283-287, 110 (2000).
  • [6] G. Federici et al., Nucl. Fusion 41, 1967 (2001).
  • [7] G. Federici et al., J. Nucl. Mater. 313-316, 11 (2003).
  • [8] J. Creel et al., “Particulate Contamination Within Fusion Devices and Complex (Dusty) Plasmas” IEEE 34th International Conference on Plasma Science (ICOPS) (2007).
  • [9] A. Miyahara and T. Tanabe, J. Nucl. Mater. 155-157, 49 (1988).
  • [10] N. Ohno et al., J. Nucl. Mater 390-391, 61 (2009).
  • [11] L. Spitzer, Astrophys. J. 93, 369 (1941).
  • [12] W.M. Tang et al., Nucl. Fusion 20, 1439 (1980).
  • [13] F. Andritsos et al., Fusion Eng. Des. 17, 409 (1991).
  • [14] M. Shoji et al., J. Plasma Fusion Res. 11, 2402056 (2016).
  • [15] P. Gasior et al., J. Nucl. Mater. 390-391, 585 (2009).
  • [16] S. Iwashita et al., Fusion Eng. Des. 88, 28 (2013).