Status of PEM-based polarimetric MSE development at KSTAR

J. Ko, J. Chung, S.T. Oh, W.-H. Ko, M.F.M. Bock, de, H. Ong, A.G.G. Lange

Research output: Contribution to journalArticleAcademicpeer-review

3 Citations (Scopus)
229 Downloads (Pure)


A multi-chord PEM (photo elastic modulator)-based polarimetric motional Stark effect (MSE) system is under development for the KSTAR tokamak. The conceptual design for the front optics was optimized to preserve not only the polarization state of the input light for the MSE measurements but also the signal intensity of the existing charge exchange spectroscopy (CES) system that will share the front optics with the MSE. The optics design incorporates how to determine the number of channels and the number of fibers for each channel. A dielectric coating will be applied on the mirror to minimize the relative reflectivity and the phase shift between the two orthogonal polarization components of the incident light. Lenses with low stress-birefringence constants will be adopted to minimize non-linear and random changes in the polarization through the lenses, which is a trade-off with the rather high Faraday rotation in the lenses because the latter effect is linear and can be relatively easily calibrated out. Intensive spectrum measurements and their comparisons with the simulated spectra are done to assist the design of the bandpass filter system that will also use tilting stages to remotely control the passband. Following the system installation in 2014, the MSE measurements are expected to be performed during the 2015 KSTAR campaign.
Original languageEnglish
Pages (from-to)1227-1231
Number of pages5
JournalJournal of the Korean Physical Society
Issue number8
Publication statusPublished - 2014


Dive into the research topics of 'Status of PEM-based polarimetric MSE development at KSTAR'. Together they form a unique fingerprint.

Cite this