a Institute of Physics, Academia Sinica, Beijing 100080, China; b Plasma Fusion Center, Massachusetts Institute of Technology, Cambridge, MA02139, U.S.A.
Abstract Resonance fluorescence of neutral hydrogen illuminated by H$\alpha$ (656.3 nm) radiation provides a technique for spatially and temporally resolved density measurements of neutral hydrogen in high temperature plasma. Experiments have been performed in the exhaust of a tandem mirror space propulsion device. The laser fluorescence signal from plasma has been separated successfully by eliminating the H$\alpha$ radiation from plasma and laser stray light using differential method of two optical paths. The resolution of signal is greatly enhanced. The radial distribution of hydrogen decreases from edge toward the center.
Received: 10 September 1992
Accepted manuscript online:
PACS:
52.25.Os
(Emission, absorption, and scattering of electromagnetic radiation ?)
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