No abstract available

[en] The Di-pentagonal Array for Nuclear Timing Experiments (DANTE) is an array of ten BaF₂ detectors used in conjunction with the 8π gamma-ray spectrometer at the TRIUMF-ISAC radioactive-ion beam facility. DANTE is used to conduct direct lifetime measurements of nuclear excited states in the picosecond - nanosecond range. This, in turn, will aid in probing the collective structures of deformed nuclei. The capability of DANTE to measure nanosecond-scale lifetimes is demonstrated by using a ¹⁵²Eu source. The half-life of the I^π = 2₁⁺ state of ¹⁵²Sm is measured to be 1.426 ± 0.018 ns.

[en] The 8π spectrometer, installed at the TRIUMF-ISAC facility, was the world's most sensitive γ-ray spectrometer dedicated to β-decay studies. A description is given of the 8π spectrometer and its auxiliary detectors including the plastic scintillator array SCEPTAR used for β-particle tagging and the Si(Li) array PACES for conversion electron measurements, its moving tape collector, and its data acquisition system. The recent investigation of the decay of "1"2"4Cs to study the nuclear structure of "1"2"4Xe, and how the β-decay measurements complemented previous Coulomb excitation studies, is highlighted, including the extraction of the deformation parameters for the excited 0"+ bands in "1"2"4Xe. As a by-product, the decay scheme of the (7"+) "1"2"4Cs isomeric state, for which the data from the PACES detectors were vital, was studied. Finally, a description of the new GRIFFIN spectrometer, which uses the same auxiliary detectors as the 8π spectrometer, is given. (paper)

[en] Excitations in 94Ru were populated through the β+/ε decay of 94Rh following the fusion evaporation reaction 58Ni(40Ca,3pn)94Rh. Recoiling nuclei were implanted on the Yale moving tape collector at the Wright Nuclear Structure Laboratory, and delayed γ-rays were observed via an array of four Compton suppressed HPGe clover detectors. Nine new γ-transitions and five new levels were added to the level scheme of (π1g(9/2))Jπ=6+4 level, in close agreement with prediction

[en] Nucleon transfer experiments have in recent years begun to be exploited in the study of nuclei far from stability, using radioactive beams in inverse kinematics. New techniques are still being developed in order to perform these experiments. The present experiment is designed to study the odd-odd nucleus ²⁶Na which has a high density of states and therefore requires gamma-ray detection to distinguish between them. The experiment employed an intense beam of up to 3×10⁷ pps of ²⁵Na at 5.0 MeV/nucleon from the ISAC-II facility at triumf. The new silicon array SHARC was used for the first time and was coupled to the segmented clover gamma-ray array TIGRESS. A novel thin plastic scintillator detector was employed at zero degrees to identify and reject reactions occurring on the carbon component of the (CD)₂ target. The efficiency of the background rejection using this detector is described with respect to the proton and gamma-ray spectra from the (d,p) reaction.

[en] A high-precision half-life measurement for the superallowed β⁺ emitter ²⁶Al^m was performed at the TRIUMF-ISAC radioactive ion beam facility yielding T_1/2=6346.54±0.46_stat±0.60_syst ms, consistent with, but 2.5 times more precise than, the previous world average. The ²⁶Al^m half-life and ft value, 3037.53(61) s, are now the most precisely determined for any superallowed β decay. Combined with recent theoretical corrections for isospin-symmetry-breaking and radiative effects, the corrected Ft value for ²⁶Al^m, 3073.0(12) s, sets a new benchmark for the high-precision superallowed Fermi β-decay studies used to test the conserved vector current hypothesis and determine the V_ud element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix.