Kankainen A, Woods P, Schatz H, Poxon-Pearson T, Doherty D, Bader V, Baugher T, Bazin D, Brown B, Browne J, Estrade A, Gade A, José J, Kontos A, Langer C, Lotay G, Meisel Z, Montes F, Noji S, Nunes F, Perdikakis G, Pereira J, Recchia F, Redpath T, Stroberg R, Scott M, Seweryniak D, Stevens J, Weisshaar D, Zegers R (2017) Measurement of key resonance states for the 30P(p, ³)31Sreaction rate, and the production of intermediate-mass elements in nova explosions, Physics Letters B 769 pp. 549-553
We report the first experimental constraints on spectroscopic factors and strengths of key resonances in the 30P(p, ³)31Sreaction critical for determining the production of intermediate-mass elements up to Ca in nova ejecta. The 30P(d, n)31Sreaction was studied in inverse kinematics using the GRETINA ³-ray array to measure the angle-integrated cross-sections of states above the proton threshold. In general, negative-parity states are found to be most strongly produced but the absolute values of spectroscopic factors are typically an order of magnitude lower than predicted by the shell-model calculations employing WBP Hamiltonian for the negative-parity states. The results clearly indicate the dominance of a single 3/2?resonance state at 196 keV in the region of nova burning TH0.10?0.17GK, well within the region of interest for nova nucleosynthesis. Hydrodynamic simulations of nova explosions have been performed to demonstrate the effect on the composition of nova ejecta.
Doherty DT, Allmond J, Janssens R, Korten W, Zhu S, Zielinska M, Radford D, Ayangeakaa A, Bucher B, Batchelder J, Beausang C, Campbell C, Carpenter M, Cline D, Crawford H, David H, Delaroche J, Dickerson C, Fallon P, Galindo-Uribarri A, Kondev F, Harker J, Hayes A, Hendricks M, Humby P, Girod M, Gross C, Klintefjord M, Kolos K, Lane G, Lauritsen T, Libert J, Macchiavelli A, Napiorkowski P, Padilla-Rodal E, Pardo R, Reviol W, Sarantites D, Savard G, Seweryniak D, Srebrny J, Varner R, Vondrasek R, Wiens A, Wilson E, Wood J, Wu C (2017) Triaxiality near the 110Ru ground state from Coulomb excitation, Physics Letters B 766 pp. 334-338
A multi-step Coulomb excitation measurement with the GRETINA and CHICO2 detector arrays was carried out with a 430-MeV beam of the neutron-rich 110Ru (t1/2=12s) isotope produced at the CARIBU facility. This represents the first successful measurement following the post-acceleration of an unstable isotope of a refractory element. The reduced transition probabilities obtained for levels near the ground state provide strong evidence for a triaxial shape; a conclusion confirmed by comparisons with the results of beyond-mean-field and triaxial rotor model calculations.
Rudigier M., Canavan R.L., Regan P.H., Söderström P.-A., Lebois M., Wilson J.N., Jovancevic N., Bottoni S., Brunet M., Cieplicka-Orynczak N., Courtin S., Doherty D.T., Hadynska-Klek K., Heine M., Iskra W., Karayonchev V., Kennington A., Koseoglou P., Lotay G., Lorusso G., Nakhostin M., Nita C.R., S. Oberstedt S., Podolyak Zs., Qi L., Régis J.-M., Shearman R., Walker P.M., Witt W. (2019) Isomer spectroscopy and sub-nanosecond half-live determination in 178w using the NuBall array, Acta Physica Polonica B 50 (3) pp. 661-667
The reaction of a pulsed 18O beam on a 164Dy target was studied in
the first experiment with the NuBall array at the IPN Orsay, France. Excited
state half-lives were measured using the fast timing method with 20
LaBr3(Ce) detectors. The timing characteristics of the fully digital acquisition
system is briefly discussed. A value for the previously unknown
half-life of the first excited 4+ state in 178W is presented.