STATUS-REPORT OF THE LEUVEN ISOTOPE SEPARATOR ONLINE (LISOL)

The mass separator LISOL, on-line to the CYCLONE cyclotron, is described as it is presently configured. The main development has been in the ion-guide operation in conjunction with light-ion induced fusion and fission. The plans to obtain intense (nA) beams of light (A less-than-or-equal-to 30), short-lived nuclei in the framework of the ARENAS3 project are also described

THE INFLUENCE OF SHAPE CHANGES ON THE ALPHA-DECAY IN THE BI-191(M,G)-]TL-187-]AU-183 CHAIN

The 191Bi(m,g) --> 187Tl --> 183Au alpha-decay chain has been studied using mass-separated sources. The alpha-branching ratios have been measured. Out of the reduced alpha-decay widths, it is clear that the pi-S1/2 --> pi-S1/3 and pi-h9/2 --> pi-h9/2 transitions are not hindered although they involve strong shape changes

ISOMERS IN 3 DOUBLY ODD FR-AT-BI ALPHA-DECAY CHAINS

The Fr-206 --> At-202 --> 198Bi, Fr-204 --> At-200 --> 196Bi, and Fr-202 --> At-198 --> 194Bi a-decay chains have been studied by standard spectroscopic techniques using an on-line isotope separator. All the studied doubly odd isotopes have at least two isomers, which decay by a combination of the following decay modes: a emission, beta+/EC (electron capture) decay, and internal transition (IT). The internal transition, a highly retarded E3, is the j-forbidden transition between the [pih9/2xnui13/2]10- and the [pih9/2xnuf5/2]7+ states. The B(E3) values of these IT's together with their energy behavior as a function of the neutron and proton number, compared to the energy difference between the 13+/2 (nui13/2) and 5-/2(nuf5/2) states in the odd-mass Pb isotones, indicate that these proton-neutron-coupled states have a rather pure shell-model character

INTRUDER STATES IN ODD ODD TL NUCLEI POPULATED IN THE ALPHA-DECAY OF ODD ODD BI ISOTOPES

The alpha-decay of mass separated Bi-190,192,194,196 isotopes has been studied with the LISOL on-line separator. Time sequential alpha-singles spectra were taken and for Bi-190,192,194, alpha-Xt and alpha-gamma-t coincidences were collected. Transition probabilities of levels in Tl-186,188,190 were measured using a fast timing alpha-gamma-t and alpha-e-t coincidence set up. The alpha-decay of 196Bi and the beta-decay of 190Bi are observed for the first time. In all the Bi nuclei presently studied, unhindered alpha-decay of Bi starting from the high- (10-) and low-spin (3+) isomer populating intruder-based states in Tl was observed. The excitation energy of these intruder states is comparable with the intruder states in the neighboring odd-even and even-even nuclei