[en] In a recent experiment to study the proton radioactivity of the highly deformed ¹³¹Eu nucleus, two proton lines were detected. The higher energy one was assigned to the ground-state to ground-state decay, while the lower energy, to the ground-state to the 2⁺ state decay. This constitutes the first observation of fine structure in proton radioactivity. With these four measured quantities, proton energies, half-life and branching ratio, it is possible to determine the Nilsson configuration of the ground state of the proton emitting nucleus as well as the 2⁺ energy and nuclear deformation of the daughter nucleus. These results will be presented and discussed

[en] Rotational bands feeding the ground state and the isomeric state in the proton emitter ¹⁴¹Ho were observed using the recoil-decay tagging method. This constitutes direct evidence that ¹⁴¹Ho is deformed. A quadrupole deformation of β₂=0.25(4) was deduced for the ground state from the extracted dynamic moment of inertia. Based on observed band crossings and signature splittings the 7/2^-[523] and 1/2⁺[411] configurations were proposed for the ground state and the isomeric state, respectively. Comparison with particle-rotor calculations for β₂=0.25 indicates, however, that ¹⁴¹Ho may have significant hexadecapole deformation and could be triaxial in the 7/2^-[523] ground state

[en] Cross sections for compound-nuclear reactions are required for many applications. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f) reactions, but need to be improved upon for applications to capture reactions.

No abstract available

[en] A new more precise measurement of the ground-state proton decay of ¹¹⁷La is presented [E_p=806(5) keV, t_1/2,p=26(3) ms]. ¹¹⁷La was produced via the p4n fusion-evaporation channel by bombarding a ⁶⁴Zn target with 310 and 295 MeV ⁵⁸Ni beams. The proton decay rate is consistent with emission from a prolate deformed 3/2⁺ or 3/2^- Nilsson state. No evidence is found for a previously reported proton decay from a high spin isomer in ¹¹⁷La. An upper limit for the production cross section for proton decay of ¹¹⁶La at a bombarding energy of 325 MeV was established

No abstract available

[en] Neutron-induced reaction cross sections are sometimes difficult to measure due to target or beam limitations. For two-step reactions proceeding through an equilibrated intermediate state, an alternate ''surrogate reaction'' technique can be applicable, and is currently undergoing investigation at LLNL. Measured decay probabilities for the intermediate nucleus formed in a light-ion reaction can be combined with optical-model calculations for the formation of the same intermediate nucleus via the neutron-induced reaction. The result is an estimation for overall (n,γ/n/2n) cross sections. As a benchmark, the reaction ⁹²Zr(α,α'), surrogate, for n+⁹¹Zr, was studied at the A.W. Wright Nuclear Structure Laboratory at Yale. Particles were detected in the silicon telescope STARS (Silicon Telescope Array for Reaction Studies) and γ-ray energies measured with germanium clover detectors from the YRAST (Yale Rochester Array for SpecTroscopy) ball. The experiment and preliminary observations will be discussed

No abstract available

[en] The mechanisms of proton radioactivity from deformed rare earth nuclei are discussed and preliminary results on the fine structure decay of ¹³¹Eu are presented

No abstract available