Alpha decay of neutron-deficient radium and francium isotopes

The main goal of the Thesis was to investigate decay properties of neutron- deficient radium and francium isotopes. Data for these isotopes were collected in two experiments performed at the velocity filter ship at GSI, Darmstadt and were analyzed by the methods ofα - and γ-decay spectroscopy. Decay properties of nine isotopes were studied: - ^201-203Ra and ^200-202Fr produced in the fusion-evaporation reactions ⁵⁶Fe+¹⁴⁹Sm and ⁵⁶Fe+¹⁴⁷Sm, - ^197-199Fr produced in the fusion-evaporation reaction ⁶⁰Ni+¹⁴¹Pr. The main results on these isotopes are: A high value of reduced α-decay width for ²⁰²Ra evaluated in this work shows a further increase of reduced -decay widths with decreasing neutron number for even-A radium isotopes. Similar trend was also observed for neighboring even-A radon and thorium isotopes in previous measurements. A remarkably high value of reduced α-decay width was also evaluated for the odd-even ¹⁹⁷Fr isotope. Although the uncertainty is large (as only one event was detected), the ¹⁹⁷Fr isotope extends the number of isotopes in this region, whose reduced α-decay widths are comparable with or even higher than reduced α-decay widths of transitions leading to regions of doubly-magic ¹⁰⁰Sn and ²⁰⁸Pb. To investigate this phenomenon in more detail, experimental data with higher statistics are necessary. The results were published in two articles in Physical Review C, in the contribution in GSI Scientific Report and were presented at international conferences. The goal of the Thesis has been achieved. (Author)