Masters Theses


"The phase shift method of measuring atomic lifetimes is particularly useful because it allows us to make measurements in the steady state mode instead of in the transient mode. High frequency phase shift techniques cause many problems. The equipment, which was designed and built to make low frequency phase shift techniques possible, is shown schematically and discussed. The new experimental techniques employed in our apparatus are a phase multiplier and a unique method of using a photomultiplier as a mixer. In the photomultiplier the final dynode is used as the grid of a triode. The next to the last dynode may be thought of as the cathode of a triode normally used as a mixer. Using the photomultiplier in this fashion, we have a low noise, extremely efficient mixer. The phase multiplier is essential to accurately measure small phase angles. The problems of high frequency techniques are cited and references given. The speed of light was measured as a test of the equipment. The experimental values resulted in a .95 confidence interval containing the generally accepted value of the speed of light in air. The average value measured was (2.937 ł .033) x 10⁸ meters per second, where .033 is the standard deviation for 48 trials. This average value represents an error of 1.61%. From the results we have established the feasibility of this low frequency method of measuring atomic lifetimes"--Abstract, page [i-ii].


Anderson, Richard A.

Committee Member(s)

Hill, Otto H.
Leighly, Hollis P., 1923-2004



Degree Name

M.S. in Physics


University of Missouri--Rolla

Publication Date



v, 29 pages


© 1969 Ronnie Carroll McMillan, All rights reserved.

Document Type

Thesis - Open Access

File Type




Subject Headings

Phase shift (Nuclear physics)

Thesis Number

T 2185

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Physics Commons