Numerical analysis of tungsten erosion and deposition processes under a DEMO divertor plasma

Yuki Homma, Kazuo Hoshino, Shohei Yamoto, Nobuyuki Asakura, Shinsuke Tokunaga, Akiyoshi Hatayama, Yoshiteru Sakamoto, Ryoji Hiwatari, Kenji Tobita, Joint Special Design Team for Fusion DEMO

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Erosion reduction of tungsten (W) divertor target is one of the most important research subjects for the DEMO fusion reactor design, because the divertor target has to sustain large fluence of incident particles, composed mainly of fuel ions and seeded impurities, during year-long operation period. Rate of net erosion and deposition on outer divertor target has been studied by using the integrated SOL/divertor plasma code SONIC and the kinetic full-orbit impurity transport code IMPGYRO. Two background plasmas have been used: one is lower density n i and higher temperature case and the other is higher n i and lower temperature case. Net erosion has been seen in the lower n i case. But in the higher n i case, the net erosion has been almost suppressed due to increased return rate and reduced self-sputtering yield. Following two factors are important to understand the net erosion formation: (i) ratio of the 1st ionization length of sputtered W atom to the Larmor gyro radius of W+ ion, (ii) balance between the friction force and the thermal force exerted on W ions. DEMO divertor design should take into account these factors to prevent target erosion.

Original languageEnglish
JournalNuclear Materials and Energy
DOIs
Publication statusAccepted/In press - 2016 Jul 15

Fingerprint

Tungsten
numerical analysis
erosion
Numerical analysis
Erosion
tungsten
Plasmas
Ions
Impurities
reactor design
impurities
ions
fusion reactors
Fusion reactors
Ionization
Sputtering
fluence
Orbits
friction
sputtering

Keywords

  • DEMO
  • Divertor
  • Erosion
  • Ionization length
  • Thermal force

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Materials Science (miscellaneous)
  • Nuclear Energy and Engineering

Cite this

Homma, Y., Hoshino, K., Yamoto, S., Asakura, N., Tokunaga, S., Hatayama, A., ... DEMO, J. S. D. T. F. F. (Accepted/In press). Numerical analysis of tungsten erosion and deposition processes under a DEMO divertor plasma. Nuclear Materials and Energy. https://doi.org/10.1016/j.nme.2017.05.003

Numerical analysis of tungsten erosion and deposition processes under a DEMO divertor plasma. / Homma, Yuki; Hoshino, Kazuo; Yamoto, Shohei; Asakura, Nobuyuki; Tokunaga, Shinsuke; Hatayama, Akiyoshi; Sakamoto, Yoshiteru; Hiwatari, Ryoji; Tobita, Kenji; DEMO, Joint Special Design Team for Fusion.

In: Nuclear Materials and Energy, 15.07.2016.

Research output: Contribution to journalArticle

Homma, Y, Hoshino, K, Yamoto, S, Asakura, N, Tokunaga, S, Hatayama, A, Sakamoto, Y, Hiwatari, R, Tobita, K & DEMO, JSDTFF 2016, 'Numerical analysis of tungsten erosion and deposition processes under a DEMO divertor plasma', Nuclear Materials and Energy. https://doi.org/10.1016/j.nme.2017.05.003
Homma, Yuki ; Hoshino, Kazuo ; Yamoto, Shohei ; Asakura, Nobuyuki ; Tokunaga, Shinsuke ; Hatayama, Akiyoshi ; Sakamoto, Yoshiteru ; Hiwatari, Ryoji ; Tobita, Kenji ; DEMO, Joint Special Design Team for Fusion. / Numerical analysis of tungsten erosion and deposition processes under a DEMO divertor plasma. In: Nuclear Materials and Energy. 2016.
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