Low Temperature Nuclear Orientation (LTNO) is an important technique in the study of nuclei far from stability. The theory of LTNO and its application to the measurement of static nuclear moments and other quantities of spectroscopic interest are reviewed. The off-line facility at Oxford was used to study the decay of <sup>133</sup>I→<sup>133</sup>Xe and <sup>135</sup>I→<sup>135</sup>Xe. <sup>133</sup>I having Z=53 and N=80 has three protons above the closed shell Z=50 and two neutrons holes in N=82 shell, while <sup>135</sup>I has fully closed neutron shell since it has N=82, and they are of considerable theoretical interest since a wide variety of the theoretical nuclear models may be used to describe the observed levels close to the stable double closed shell structure. Another aim is to search for the nuclear magnetic dipole moment of the ground state of <sup>135</sup>I. Nuclear orientation of <sup>133</sup>IFe and <sup>135</sup>IFe enabled the mixing ratios of several transitions in the decay scheme of <sup>133</sup>I and <sup>135</sup>I to be determined. From temperature dependence for <sup>135</sup>I, the nuclear magnetic moment of <sup>135</sup>I has been deduced. Also temperature dependence for <sup>133</sup>I, analysed using a simple model, gave value for the magnetic hyperfine field that differed from previous published values. The method of combining nuclear orientation with NMR has become a very popular technique in recent years for determining nuclear magnetic dipole moments very precisely. The purpose of the NMR/ON experiment was to measure the hyperfine field with greater precision and to get some idea of the proportion of nuclei subject to it. Light Eu and Sm nuclei have attracted attention as systems with the number of protons right below the Z=64 subshell gap and the number of neutrons approaching N=82 major shell closure. Odd-proton, odd-neutron and odd-odd nuclei near the A=140 region have been investigated in the framework of the particle-triaxial rotor model. Main attention has been paid to explanation of experimental magnetic dipole and electric quadrupole moments of ground and isomeric states. Model predictions for deformation parameters of <sup>136-142</sup>Sm even-even cores have been extracted.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:259978 |
| Date | January 1994 |
| Creators | Koh, Young |
| Contributors | Stone, N. J. |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://ora.ox.ac.uk/objects/uuid:fa4e489d-a235-4787-aab1-60f5a3b14c23 |
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