An overview of the motional Stark effect diagnostic on DIII-D and design work for an ITER MSE

C. T. Holcomb, S. L. Allen, M. A. Makowski, R. J. Jayakumar, M. F. Gu, S. Lerner, K. L. Morris, J. Latkowski, J. M. Moller, W. Meyer, R. Ellis, R. Geer, D. Behne, R. Chipman, P. Smith, S. McClain

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Scopus citations


The advanced tokamak research program at DIII-D relies critically on the measurement of the current density profile. This was made possible by the development of a Motional Stark Effect (MSE) polarimeter that was first installed in 1992. Three major upgrades have since occurred, and improvements in our understanding of critical performance issues and calibration techniques are ongoing. In parallel with these improvements, we have drawn on our DIII-D experience to begin studies and design work for MSE on burning plasmas and ITER. This paper first reviews how Motional Stark Effect polarimetry (MSE) is used to determine the tokamak current profile. It uses the DIII-D MSE system as an example, and shows results from the latest upgrade that incorporates an array of channels from a new counter-Ip injected neutral beam. The various calibration techniques presently used are reviewed. High-leverage or unresolved issues affecting MSE performance and reliability in ITER are discussed. Next, we show a four-mirror collection optics design for the two ITER MSE views. Finally, we discuss measurements of the polarization properties of a few candidate mirrors for the ITER MSE. Work supported by the U.S. Department of Energy under W-7405-ENG-48.

Original languageEnglish (US)
Title of host publicationBurning Plasma Diagnostics - An International Conference
Number of pages4
StatePublished - 2008
EventInternational Conference on Burning Plasma Diagnostics - Varenna, Italy
Duration: Sep 24 2007Sep 28 2007

Publication series

NameAIP Conference Proceedings
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616


OtherInternational Conference on Burning Plasma Diagnostics


  • Calibration
  • Current profile
  • ITER
  • Mirrors
  • Motional Stark Effect
  • Optical diagnostic

ASJC Scopus subject areas

  • General Physics and Astronomy


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