PhD (Edinburgh) MPhys (Warwick)
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 Elsevier
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 Elsevier
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.