Application of two-photon-excited laser-induced fluorescence to atomic hydrogen measurements in the edge region of high-temperature plasmas
- Department of Energy Conversion, Graduate School of Engineering Sciences, Kyushu University, Kasuga, Fukuoka 816 (Japan)
- Department of Electrical Engineering, Faculty of Engineering, Kyushu University, Hakozaki, Fukuoka 812 (Japan)
- Plasma Physics Laboratory, Kyoto University, Gokasho, Uji, Kyoto 611 (Japan)
A two-photon-excited laser-induced fluorescence (LIF) was applied to measurement of atomic hydrogen densities in the edge region of high-temperature plasmas of Heliotron E for the first time. In this application, fluorescence signals were observed coaxially to the laser beam. This was possible because, in two-photon-excitation LIF, the visible fluorescence is localized at the laser focus and stray light can be completely eliminated by optical spatial filters, allowing much easier optical access than in previous LIF experiments. The densities at the initiation of the discharge and at the quasisteady state of the discharge were determined to be 3{times}10{sup 16} and 1{times}10{sup 16} m{sup {minus}3}, respectively within an error of a factor of 2. Optimization to maximize the signal-to-noise ratio of the observation and resulting detection limit were discussed and confirmed the above results.
- OSTI ID:
- 5242436
- Journal Information:
- Review of Scientific Instruments; (United States), Vol. 62:10; ISSN 0034-6748
- Country of Publication:
- United States
- Language:
- English
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