Studies on Absorptive Transitions Between Rotational Sublevels of Symmetric-Top Molecules in a Static Electric Field

Citation

Thiene, Paul George, Jr. (1952) Studies on Absorptive Transitions Between Rotational Sublevels of Symmetric-Top Molecules in a Static Electric Field. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/MS6H-6Z64. https://resolver.caltech.edu/CaltechTHESIS:04172018-105411908

Abstract

The topic of this research is the hitherto uninvestigated absorption of electromagnetic energy by polar symmetric-top molecules in a static electric field, which arises by virtue of direct transitions between sublevels of a single rotational state. A short theoretical treatment of the Stark effect of a rigid molecule is included. The factors governing the absorption of quanta from the surrounding radiation field are discussed in a rudimentary derivation of a formula for the maximum linear absorption coefficient of a gas.

A new microwave Stark-effect spectrometer constructed for an exploratory investigation is described. The instrument operates in an unusual manner whereby the spectral position of the absorption line is varied, while the frequency of the incident radiation is held fixed. Included also is a treatment of the factors which determine and limit the sensitivity of the spectrometer.

Experiments which strongly indicate the existence of these field-created absorption lines are reported.

Thesis Files