Search for the Mössbauer Effect in 109Ag

<p>The 88-keV first-excited nuclear state in ¹⁰⁹Ag has a mean lifetime of 57.1 sec and a corresponding natural linewidth of 1.15 x 10^-17 eV which is nearly six orders of magnitude narrower than the width for the 93-keV 13.2-μsec state in ⁶⁷Zn. The 93-keV transition in ⁶⁷Zn has the narrowest linewidth for which the Mossbauer effect has been observed. The 88-keV transition in ¹⁰⁹Ag is obviously a very difficult case for the observation of the Mossbauer effect and provides a stringent test for exploring the practical limits of inhomogeneous line broadening in real single crystals.</p> <p>In the past, two attempts have produced evidence for the occurrence of the Mossbauer effect in ¹⁰⁹Ag. However, more detailed, corroborating results are needed to substantiate such positive results.</p> <p>This dissertation reports the results of a series of self-absorption experiments using ¹⁰⁹Cd-doped single-crystal samples of natural silver to observe the Mossbauer effect in ¹⁰⁹Ag. In addition to measuring the temperature dependence of the 88-keV gamma rays emanating from the samples, the changes in the accompanying x rays were also monitored to account for problems associated with the temperature dependence of the solid angle subtended by the detector. The data were analyzed by a parametric model simulating the experiments.</p> <p>The results of these self-absorption experiments in the vertical geometry indicated a clear, positive Mossbauer effect. The measured effective cross section was only two orders of magnitude smaller than the theoretical value of maximum resonance cross section (4.56x10^-20 cm²). Such a large effective cross section implies an effective linewidth (neglecting the effect of the gravitational redshift and the ambient magnetic field) approximately 50 times the natural linewidth. This is a surprisingly small amount of broadening which is currently not understood.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Year dc:date.available

1992

Author dc:creator

• Rezaie-Serej, Shokrollah

Contributors dc:contributor

• Gilbert R. Hoy
• Desmond Cook
• Gary Copeland
• Mark Havey
• Linda Vahala

• Silver-109
• Mössbauer effect
• Nuclear

Statement dc:rights

• <p>In Copyright. URI: <a href="http://rightsstatements.org/vocab/InC/1.0/">http://rightsstatements.org/vocab/InC/1.0/</a> This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).</p>

Repository record dc:identifier

https://digitalcommons.odu.edu/physics_etds/109

OAI identifier oai:identifier

oai:digitalcommons.odu.edu:physics_etds-1115