Results 1 - 10 of 236
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[en] The measurement of the resonant alpha scattering and the 21Na(α, p) reaction were performed for the first time in inverse kinematics with the thick target method using a 21Na radioisotope (RI) beam. This paper reports the current result of alpha scattering measurement and its astrophysics implication.
[en] The authors report the recent progress on laser manipulation of the short-lived (22 sec half-life) radioactive 21Na atoms. Since they successfully demonstrated laser trapping of short-lived radioactive isotope at LBL's 88 inch Cyclotron, the authors have made substantial improvements in their experimental apparatus. Using a new high temperature oven and MgO target, the thermal atomic beam of 21Na has been greatly increased. A new trapping magnet has been fabricated, which promises higher trapping efficiency. Currently they are working on the precise measurement of the hyperfine structure of the 21Na and new laser trapping schemes which provide polarized trapped atoms. These techniques will lead to a precision measurement of the decay asymmetry parameter, which is a sensitive test of the V-A structure of the weak charged current
[en] At the KVI preparations are underway to study time-reversal violation. We will discuss two complementary experiments: Correlations in β decay of 21Na and the search for an electric dipole moment in Radium. We discuss the complementarity of these measurements and put them in the context of current research.
[en] We produced 211At by irradiating the semi-sealed encapsulated Bi target with an external vertical beam. At 28.5 MeV, the yield of 211At was 22 MBq/μA h (600 μCi/μA h). 211At was recovered by dry distillation, and 80% of the produced 211At was successfully obtained in dry Na211At form within 2 h from the end of bombardment (EOB). The radionuclidic purity of 211At was >99% at 5 h from EOB. - Highlights: • We generated 211At from a semi-sealed capsulated target by using a vertical beam. • Using a 28.5 MeV beam on the target, the yield was 22 MBq/μA h. • Dry Na211At was obtained within 2.3 h from EOB. • 80% of the produced 211At was recovered by dry distillation. • Radionuclidic purity of the obtained 211At was >99% at 5 h from EOB
[en] A series of astrophysical measurements was recently completed at TRIUMF, related to the unknown total rate of the 21Na(p, γ)22Mg reaction. With a high intensity 21Na beam from the ISAC facility, the DRAGON recoil mass spectrometer was used to directly measure seven resonances at center of mass energies from Ec.m.=200 to 1135 keV and determine their respective contributions to the 21Na(p, γ)22Mg reaction rate in novae and x-ray bursts, as well as their impact on 22Na production in novae. This study also allowed the investigation of different excited states in 22Mg; proposed decays and spin assignments are given for the 6246, 6329, and 6609 keV levels
[en] Mass measurements with a relative precision of better than 1.5 x 10-8 were performed on 22Mg and its reaction partners 21Na and 22Na with the ISOLTRAP penning trap mass spectrometer at CERN, yielding the mass excesses D(22Mg) = -399.92(27) keV, D(21Na) = -2184.71(21) keV, and D(22Na) = -5181.56(16) keV. The importance of these results is twofold: First, a comparative half-life (Ft value) has been obtained for the superallowed β decay of 22Mg to further test the conserved-vector-current hypothesis. Second, the resonance energy for the 21Na proton capture reaction has been independently determined, allowing direct comparisons of observable γ radiation in nova explosions with the yield expected from models. (orig.)
[en] The ISAC (Isotope Separator and Accelerator) Radioactive Beams laboratory has been in operation for about 4 years. An upgrade in the RB upper energy and mass range will be operational in 2 years and funding for a further upgrade in available number of RB will be submitted this year. There are a number of major experimental facilities now available with physics results produced. A key new facility in the area of nuclear astrophysics, the DRAGON (Detector of Recoils And Gammas Of Nuclear reactions) facility, has finished its first major study, namely a direct measurement for the first time of the 21Na(p,γ)22Mg reaction, a reaction believed to play a key role in the production of 22Na during novae explosions. This report will provide a review of the experimental facilities now available at ISAC, along with details of this first published result from the DRAGON facility