Measurement of plasma centroid position on ISTTOK using cleaned magnetic signals

O. Kudlacek, C. Finotti, G. Marchiori, B.B. Carvalho, R. Henriques, H. Figuereido, H. Fernandes

Research output: Contribution to conferencePaper

Abstract

ISTTOK [1] is a large aspect ratio tokamak operated in Lisbon. One of the most important features of this machine is the capability of performing AC discharges that are much longer than the standard DC ones [1]. On the other hand, especially after the plasma current reversal, the usual measurement of the plasma centroid by magnetic diagnostics was not reliable since the signals were corrupted by the eddy currents induced by the variations of poloidal field coil currents. Up to now, an alternative technique of the plasma centroid position measurement based on the plasma potential value provided by Langmuir probes has been used. The drawback of this alternative method is that the results can be affected by perturbations of the plasma edge. To enable the usage of more standard method based on magnetic diagnostics, a simple, efficient and real-Time applicable method of magnetic signal cleaning from the eddy currents effect was proposed. It is based on a fitted state-space model describing the dependency of the magnetic signal on the currents in the poloidal field coils taking into account the conductive structures surrounding the plasma. The fit was performed based on experimental data. Afterwards, an algorithm described in [4] for the plasma centroid position measurement was modified to deal with the ISTTOK geometry.
Original languageEnglish
DOIs
Publication statusPublished - 31 May 2016
Externally publishedYes
Event26th IEEE Symposium on Fusion Engineering, SOFE 2015 - Austin, United States
Duration: 31 May 2016 → …

Conference

Conference26th IEEE Symposium on Fusion Engineering, SOFE 2015
CountryUnited States
CityAustin
Period31/5/16 → …

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All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Nuclear Energy and Engineering

Cite this

Kudlacek, O., Finotti, C., Marchiori, G., Carvalho, B. B., Henriques, R., Figuereido, H., & Fernandes, H. (2016). Measurement of plasma centroid position on ISTTOK using cleaned magnetic signals. Paper presented at 26th IEEE Symposium on Fusion Engineering, SOFE 2015, Austin, United States. https://doi.org/10.1109/SOFE.2015.7482306