TDPAD measurement of g-factors in 179W

Full text: The g-factors of the 35/2- and 21/2+ states in 179W have been measured using the time differential perturbed angular distribution (TDPAD) technique. States in 179W were populated in the 170Er(l3C, 4n) reaction at an energy of 65 MeV, with beams provided by the ANU 14UD accelerator. A thin, 580 ,μgcm-2, enriched target was used, with the tungsten nuclei recoiling into a thick-thallium foil heated to 260 deg C. The thallium host was chosen to avoid disorientation effects and to measure the g-factors in an environment similar to parallel measurements of quadrupole moments for the same states. A field of 2.43(2)T was applied using an external electromagnet. A pulsed beam of width < 1ns and separation 3.85 μs was used with γrays measured in two Ge detectors positioned at ±135 deg C to the beam axis and time signals measured using a common TAC. Data were recorded in event-by-event and the time spectra for particular transitions were obtained from γ-time matrices with appropriate subtraction to remove contributions from Compton scattered events. Time spectra obtained from summing a number of transitions de-exciting the 35/2- isomer are shown in the figure together with the fits to the data. The mean-lives and g-factors from the measurement are tabulated below. The calculated values are appropriate for the configurations suggested in. In addition to the measurements for 179W, g-factors were also obtained for states in thallium and francium nuclei which agree well with previously measured values