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 ?)
Altmetric calculates a score based on the online attention an article receives. Each coloured thread in the circle represents a different type of online attention. The number in the centre is the Altmetric score. Social media and mainstream news media are the main sources that calculate the score. Reference managers such as Mendeley are also tracked but do not contribute to the score. Older articles often score higher because they have had more time to get noticed. To account for this, Altmetric has included the context data for other articles of a similar age.