Plasma and Fusion Research

Volume 14, 2402140 (2019)

Regular Articles

Application of He I Line Intensity Ratio Method to Lyot-Filter-Based Imaging Spectrometry on MAP-II Divertor Simulator
Shinichiro KADO
Institute of Advanced Energy, Kyoto University, Uji 611-0011, Japan
(Received 3 October 2018 / Accepted 2 July 2019 / Published 25 September 2019)


A simple, yet advanced technique of imaging spectrometry of divertor-relevant low-temperature plasmas using a wavelength-tunable Lyot filter spectral camera is herein proposed. The influence of the radiation-trapping effect in the atomic helium line intensity ratio method, characterized by the trapping radius, Lq, can be reduced using only the triplet series: 471(43S)-, 587(33D)-, and 706(33S)-nm lines that are included in the tunable range of the above-mentioned Lyot filter. Approximate values of Lq can be estimated by adding 501(31P)- and 667(31D)-nm singlet lines, which enables stand-alone parameter imaging considering the radiation trapping.


Lyot filter, imaging spectroscopy, line intensity ratio, atomic helium line, leak band, collisional-radiative model, radiation trapping

DOI: 10.1585/pfr.14.2402140


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