| Popis: |
Excited states in the neutron-deficient transitional nuclei ¹¹²ʼ¹¹⁴ʼ¹¹⁶Te have been studied by means of heavy-ion (H.I.,xnypzα) reactions. Levels up to spin 22n at excitation energies of up to 9 MeV were established using Υ-Υ coincidence, Υ-ray angular distribution, Υ-ray excitation function and, in the case of ¹¹²Te, Υ-Υ-time measurements. In addition, the characteristics of a number of fusion-evaporation reactions leading to residual nuclei in this region have been analyzed and compared to theoretical predictions. Positive-parity structures above spin 4⁺, 8⁺ and 14⁺ in ¹¹²Te, ¹¹⁴Te and ¹¹⁶Te respectively as well as negative-parity bands based on 8⁽⁻⁾ and 9⁽⁻⁾ states are reported for the first time. Positive- and negative-parity band structures up to spin 16⁺ are compared to the predictions of a number of models usually applied to transitional nuclei, and interpreted in terms of valence single-particle plus collective vibrational degrees of freedom. At higher spins (12n to 22n) no strong evidence for rotational structure is seen. As part of the data analysis for the present work, a numerical deconvolution method appropriate to Υ-ray spectra is presented in the Appendix. Doctor of Philosophy (PhD) |
