TITLE

Practical selection of emission lines of He I to determine the photon absorption rate

AUTHOR(S)
Kajita, Shin; Ohno, Noriyasu
PUB. DATE
February 2011
SOURCE
Review of Scientific Instruments;Feb2011, Vol. 82 Issue 2, p023501
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
A combination of helium line intensities and a collisional radiative model has been used to measure electron density and temperature. However, radiation trapping of resonance lines may disturb the measurements due to disturbances in the population distribution of helium atoms. In this study, we show that the principal contribution of radiation trapping in helium plasma can be evaluated by additionally measuring one or two specific line intensities from the singlet state. The inclusion of the effects of radiation trapping sufficiently compensates for anomalous increases in the electron density and temperature, and consequently yields proper values. An experiment was performed in the divertor simulator NAGDIS-II, and the method's validity was confirmed by comparing the spectroscopically obtained results and the values from the electrostatic probe method.
ACCESSION #
58700521

 

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