Detection of mercuric chloride by photofragment emission using a frequency-converted fiber amplifier
- Sandia National Laboratories, Livermore, CA (United States)
A real-time, noninvasive approach for detecting trace amounts of vapor-phase mercuric chloride (HgCl{sub 2}) in combustion flue gas is demonstrated using a near-infrared pulsed fiber amplifier that is frequency converted to the ultraviolet. Excitation of the HgCl{sub 2} (1{Pi}1{sub u}{l_arrow} 1{Sigma}1g+) transition at 213 nm generates 253.7 nm emission from the Hg (6{sup 3}P{sub 1}) photoproduct that is proportional to the concentration of HgC1{sub 2}. A measured quadratic dependence of the HgCl{sub 2} photofragment emission (PFE) signal on the laser irradiance indicates that the photodissociation process involves two-photon excitation. Additionally, low concentrations of HgCl{sub 2} are detected with the PFE approach in an environment characteristic of coal-fired power-plant flue gas using this compact solid-state laser source. A detection limit of 0.7 ppb is extrapolated from these results.
- OSTI ID:
- 20939567
- Journal Information:
- Applied Optics, Journal Name: Applied Optics Journal Issue: 19 Vol. 46; ISSN 0003-6935; ISSN APOPAI
- Country of Publication:
- United States
- Language:
- English
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