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| Titel |
ROFLEX: Resonance and Off-Resonance Fluorescence by Lamp Excitation for in situ detection of atomic and molecular iodine. |
| VerfasserIn |
Juan Carlos Gomez Martin, Janis Blahins, Uldis Gross, Trevor Ingham, Andrew Goddard, Anoop Sharad Mahajan, Arnolds Übelis, Alfonso Saiz-Lopez |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250046412
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| Zusammenfassung |
| We present a new instrument for monitoring in situ atmospheric iodine atoms and
molecules based on the detection of UV fluorescence excited by atomic lines radiated
by a lamp. The ROFLEX system combines a robust, light weighted and efficient
radio-frequency discharge light source with two high sensitive photon counting modules.
Calibration of I2 off-resonance fluorescence at 300 - 340 nm is achieved via quantitative
detection of the molecule by Incoherent Broad Band Cavity-enhanced Absorption
Spectroscopy. The atomic iodine resonance fluorescence signal at 183.038 nm is calibrated
by broad band photolysis of known I2 concentrations. The instrument has been
characterised and optimised in laboratory experiments to reach detection limits
of 1.2 pptv for I atoms and 13 pptv for I2 (S/N=1 and 10 minutes of integration
time). Finally, results will be presented from the ROFLEX deployment in a field
campaign in the Galician coast (Spain), representing the first concurrent observation
of ambient mixing ratios of iodine atoms and molecules in the 1-350 pptv range. |
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