First measurement in the Gamow window of a reaction for the γ-process in inverse kinematics: 76Se(α,γ)80Kr

Beyond the acceptance limit of DRAGON: The case of the 6Li(α,γ)Psaltis1, Chen2, Connolly3 et al. 2021Nuclear Instruments and Methods in Physics Research Section A: Self Cite3020View full textAdd to dashboardCite

“…The data analysis is also affected by our knowledge of the γ branching ratios and angular distributions W(θ), as discussed in Section 2. Accurate measurements of the γ branching ratios using high efficiency detectors are desirable, but even if they are unknown, the γ ray detection efficiency can still be Table 6: Summary of reported energies for the E x = 5920 keV state of 10 B from different measurements, normalized to the current 6 Li(α, γ) 10 B reaction Q value [12]. See the text for a detailed discussion.…”

“…For example, the 7 Be(p, γ) 8 B reaction, with a Q value of 136.4 keV can be a very challenging measurement for resonances with E r > Q, since θ r,max increases with increasing energy [1]. On the other hand, for resonances with E r ∼ 1 MeV, typical for astrophysical environments, the 6 Li(α, γ) 10 B (Q-value = 4461.19 keV), has a decreasing θ r,max with increasing energy, which is similar to the 7 Be(α, γ) 11 C reaction (Q-value = 7543.6 keV), and for this reason is a good choice for a surrogate reaction. For a more detailed discussion regarding the kinematics formalism of radiative capture reactions using recoil separators for astrophysics the reader is referred to References [1,2].…”

“…The Detector of Recoils and Gammas of Nuclear reactions (DRAGON) facility in the Isotope Separator and Accelerator-I (ISAC-I) experimental hall at TRIUMF, Canada's particle accelerator centre in Vancouver, BC has carried out many of the radiative capture measurements involving radioactive ion beams to date. Even though it was constructed to study reactions with beams up to A=30 [3,4], over the last two decades, DRAGON has demonstrated versatility, having performed experiments from A= 3, e.g., 3 He(α, γ) 7 Be [5], to A= 76, e.g., 76 Se(α, γ) 80 Kr [6].…”

“…Schematic representation of a radiative α-capture on6 Li in inverse kinematics: (a) beam ( 6 Li) and target ( 4 He) particles interact, (b) the compound nucleus ( 10 B) is synthesised in an excited state and then, (c) it decays by emitting a γ ray. The recoil nucleus and the γ ray are emitted in angles θ r and θ γ in the lab system respectively.…”

“…GEANT simulation results for the recoil angular distribution of the E r = 1458.5 keV resonance of6 Li(α, γ) 10 B reaction by changing (Left) the number of γ rays emitted in the cascade and (Right) their angular distribution (Dipole -W(θ) ∝ sin 2 θ, Uniform -W(θ) = 1 and Quadrupole -W(θ) ∝ sin 2 θ cos 2 θ.) The vertical line shows DRAGON's angular acceptance, ±21 mrad.…”