Smith, Anthony Lewis Stapley (1966) Single- and multi- cavity beam masers for microwave and ultramicrowave frequencies. Doctoral thesis, Keele University.

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Abstract

An amnonia beam maser with a single resonant cavity and with two cascaded cavities is investigated.
A single cavity microwave beam maser is described and its characteristics of operation determined. This maser is constructed so that a second resonant structure can be inserted between the state separator and the main cavity. This second structure can either be another cylindrical microwave cavity or a Fabry-Perot spherical mirror inter- ferometer.
With the two microwave cavity system 'molecular ringing' effects are observed and these have been examined in detail. The system is found to act as an amplifier and as a very sensitive spectrometer, Previously unresolved hyperfine structure of ammonia is observed.
The normal microwave ammonia beam maser uses the inversion splitting of the J = K = 3 rotational level. Other rotational levels are also split and molecules in certain of these can be state selected by a multi-pole or ring electrostatic separator. A double resonance experiment using common rotational and inversion levels is considered as a means of detecting ultramicrowave stimulated emission by monitoring the oscillation at the microwave inversion transition frequency.
The design of separators and resonators for ultramicrowave (125µ) radiation is reported and the construction of a far infrared grating spectrometer to test components and systems for the double resonance maser is described.
Preliminary experiments are described for a double resonance system, with the first resonator taking the form of a half confocal cavity. The sensitivity of this detection system is evaluated.

Item Type: Thesis (Doctoral)
Subjects: Q Science > QC Physics
Divisions: Faculty of Natural Sciences > School of Chemical and Physical Sciences
Depositing User: Lisa Bailey
Date Deposited: 27 Mar 2018 11:42
Last Modified: 27 Mar 2018 11:42
URI: http://eprints.keele.ac.uk/id/eprint/4660

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