Zero-field level crossing techniques have been used to measure some upper state lifetimes of the helium atom. The upper states of the atom were excited in a discharge between two capacitor plates. A radio frequency voltage was applied to these plates by a 450 MHz source. The emitted light was modulated by rotating a quarter-wave plate in front of a polaroid in the beam of emitted light. The polarization, which is directly related to this modulation, was measured by a phase sensitive lock-in amplifier.
The halfwidths of curves obtained by plotting the polarization against the magnetic field strength for the n¹D - 2¹P transitions yielded lifetimes of; 2.71 x 10(-8) sec. for the 3¹D state, 3.97 x 10(-8) sec. for the 4¹D state and 4.48 x 10(-8) sec. for the 5¹D state. / Science, Faculty of / Physics and Astronomy, Department of / Graduate
| Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/34507 |
| Date | January 1970 |
| Creators | Bardsley, Robert Eckardt |
| Publisher | University of British Columbia |
| Source Sets | University of British Columbia |
| Language | English |
| Detected Language | English |
| Type | Text, Thesis/Dissertation |
| Rights | For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use. |
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