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Location:
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KFC Courts |
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Date:
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Tuesday, Aug.02 |
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Time:
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5:15PM - 6:00PM
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Author:
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David A. Olsgaard, Simpson College
515-961-1829, david.olsgaard@simpson.edu
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Co-Author(s):
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Mike Henry, Austin Roy, Tayler Buresh
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Abstract:
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Many laser spectroscopy experiments utilizing rubidium vapor cells have been demonstrated in the undergraduate laboratory. We introduce three new undergraduate spectroscopy experiments using rubidium vapor cells back-filled with an argon buffer gas. These experiments introduce students to the role elastic and inelastic collisions can play in the absorption and emission spectrum of atoms. The first experiment is a dramatic demonstration of hyperfine optical pumping aided by velocity-changing collisions with the buffer gas in which we observe 100% transfer of population to one hyperfine level. The second experiment shows an unexpected modification of the rubidium fluorescence spectrum as a function of argon pressure and laser intensity. A simplified 3-level rate equation model predicts the unusual feature. The third experiment is the observation of a decrease in the excited state lifetime of the 6P3/2 level as function of buffer gas pressure. A Stern-Volmer plot yields the inelastic collision cross-section.
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Footnotes:
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None
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