Computer Science – Performance
Scientific paper
Sep 2009
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009dps....41.1706w&link_type=abstract
American Astronomical Society, DPS meeting #41, #17.06
Computer Science
Performance
Scientific paper
The previous apparatus available for gas phase cross-section measurements in our laboratory had a low temperature limit of 150 K, the limit of a commercial heavy-duty triple-cascade refrigerant cooling system. To extend the capability to lower temperatures other types of cooling are required. We have thus fabricated and tested the operation of a windowless cell device. Inside an ultrahigh vacuum chamber the new windowless absorption cell is cooled by a variable temperature liquid nitrogen cooling system. A Lakeshore temperature controller and a fast response temperature sensor are utilized to regulate the temperature of the cell. The new apparatus can in principle be operated at a temperature as low as 77 K. However, we can only carry out measurements at a temperature that will provide sufficient gas pressure in the wavelength range of interest.
We have obtained preliminary cross-section results for C2H2 in the 146-154 nm region at temperatures as low as 130 K. The effective pathlength of the windowless cell has been determined by calibrating against the cross-section data obtained by a closed absorption cell with LiF windows at 295 K, 180 K, and 150 K. We found that the effective pathlengths determined do not depend on temperature under the present experimental conditions. Its value is consistent to within an uncertainty of 8%. The design of the new apparatus, its performance, and results will be presented.
It is our goal to provide the currently unavailable, but crucial data required low-temperature absorption cross-sections of CH4, C2H2, and other light hydrocarbons in order to correctly interpret the atmospheric occultation probe data of Saturn, Titan and the outer planets. The new data will put definitive constraints on the physical chemistry, radiative cooling, and atmospheric dynamics of Titan and Saturn.
Fung Hok-Sum
Judge Darrell L.
Lin Yen-Chih
Luo J. I.
Wu Chung-Yung Robert
No associations
LandOfFree
A New Windowless Apparatus for Low-Temperature Absorption Cross-Section Measurements does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A New Windowless Apparatus for Low-Temperature Absorption Cross-Section Measurements, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A New Windowless Apparatus for Low-Temperature Absorption Cross-Section Measurements will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1332348