Moessbauer spectroscopy interference measurements in tungsten, iridium, and terbium
Abstract
We made precise final state interference measurements using very intense Mossbauer sources and exact line-shape analysis. Three transitions in tungsten, as well as one in iridium metal and terbium oxide, have been studied. The dispersion terms 100$\beta$ measured were $-$0.318(5) for 46.5-keV $\sp{183}$W, $-$1.3(3) for 99.1-keV $\sp{183}$W, $-$1.2(1) for 100.1-keV $\sp{182}$W, $-$0.71(8) for 129.4-keV $\sp{191}$Ir, and $-$0.48(5) for 58.0-keV $\sp{159}$Tb. Our $\beta$ in 46.5-keV $\sp{183}$W was found using a double absorber technique and agreed extremely well with what we found earlier using the standard transition geometry, and differs from theory values by $\approx$10%, indicating the theoretical values need refinement if they're to be used in time reversal invariance studies. Our remaining values agree with theory, but haven't been measured to the percent accuracy of the 46.5-keV case. Our measurement of 1.16(2) cm/s for the $\sp{191}$Ir line width agrees with other Mossbauer measurements and shows no indication of hyperfine broadening. The appendix explains how to fit data to a true line-shape expression including source resonant absorption, reports a $\gamma$-ray scattering experiment measuring the change in recoilless fraction following Bragg scattering from NaCl, NaF, and LiF, and gives results of an attempt to observe a nuclear Casmir effect in $\sp{193}$Ir.
Degree
Ph.D.
Advisors
Mullen, Purdue University.
Subject Area
Condensation|Nuclear physics|Radiation
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