EPJ Web of Conferences (Jan 2017)

Characterization of 3-strap antennas in ASDEX Upgrade

  • Bobkov Volodymyr,
  • Bilato Roberto,
  • Colas Laurent,
  • Dux Ralph,
  • Faudot Eric,
  • Faugel Helmut,
  • Fünfgelder Helmut,
  • Herrmann Albrecht,
  • Jacquot Jonathan,
  • Kallenbach Arne,
  • Milanesio Daniele,
  • Maggiora Riccardo,
  • Neu Rudolf,
  • Noterdaeme Jean-Marie,
  • Ochoukov Roman,
  • Pütterich Thomas,
  • Tierens Wouter,
  • Zhang Wei,
  • ,

DOI
https://doi.org/10.1051/epjconf/201715703005
Journal volume & issue
Vol. 157
p. 03005

Abstract

Read online

The response of the local RF current measured at limiters of 3-strap ICRF antenna to variations of power balance and phasing at fICRF=30MHz agrees qualitatively well with EM calculations by TOPICA and RAPLICASOL codes. Measurements of tungsten sputtering yield and DC current at the limiters correlate strongly with the local RF current. In contrast to findings for the 2-strap antennas, values of DC current are predominantly positive, and negative only for some locations and feeding parameters. Explanations can involve more physical mechanisms than only parallel sheath dynamics.