1. 9/15/04B. Azmoun1 Transmittance as a Function of Water and Oxygen Levels in the VUV Regime Bob Azmoun, Brookhaven National Lab

2. 2 Apparatus Injecting ppm’s of H2O Injecting ppm’s of O2 VUV Spectrometer Micrometer Valve ~15psig Bubbler filled with pure distilled water Mass Flow Controller ~2psi over- pressure H2O/O2 Analyzer Pressure Controller Vent

3. 3 Results Reference: Attenuation Coefficient for O2Reference: Interaction Cross Sect. for H2O

4. 4 Integrated Transmittance

5. 5 Level of agreement with results found in the prevailing literature

6. 6 Conclusions The results above have been verified by two independent sources Interaction X-sect. for H2O & Attenuation Coefficient for O2 from literature, and two transmittance measurements using two bottles of Ar with calibrated levels of O2 In order to preserve roughly 95% of light in the range from 1120- 2000 Angstroms, the water vapor and O2 concentrations must kept below 10 and 15ppm’s respectively within the gas(for a 36cm gas absorber)