Measurement of the ⁹¹Zr(p,γ)^92m Nb cross section motivated by type Ia supernova nucleosynthesis

Abstract

The synthesis of heavy, proton rich isotopes is a poorly understood astrophysical process. Thermonuclear (type Ia) supernova explosions are among the suggested sites and the abundance of some isotopes present in the early solar system may be used to test the models. 92 Nb is such an isotope and one of the reactions playing a role in its synthesis is 91 Zr(p,γ) 92 Nb. As no experimental cross sections were available for this reaction so far, nucleosynthesis models had to solely rely on theoretical calculations. In the present work the cross section of 91 Zr(p,γ) 92m Nb has been measured at astrophysical energies by activation. The results excellently confirm the predictions of cross sections and reaction rates for 91 Zr(p,γ) 92 Nb, as used in astrophysical simulations.

Nuclear Physics Opportunities at European Small-Scale Facilities

“…92 Nb is one of the isotopes present in the early Solar system which may be used to test the models since among the suggested sites is a thermonuclear supernova explosion. The cross section of the 91 Zr(p,γ) 92m Nb has been measured using the activation method (only the partial cross section leading to the isomeric state of 92 Nb could be measured as the ground state has a half-life of 3.47•10 7 years) [82]. The theoretical cross sections employed in previous astrophysical models and the 91 Zr(p,γ) 92m Nb measurements showed good agreement.…”

Cross section measurement of the 144Sm(alpha,n)147Gd reaction for studying the alpha-nucleus optical potential at astrophysical energies

“…With one exception, a single target was irradiated in a single activation run. In the case of the E α = 20 MeV irradiation, however, two targets were placed in the chamber, one behind the other, separated by a 10 µm thick Al energy degrader foil, similar to the procedure of a recent experiment described in [20]. The thickness of the degrader foil was measured with α energy loss to a precision of 5 % which was used for the effective energy determination at the second target (see section II D).…”

Nuclear Physics Opportunities at European Small-Scale Facilities

“…The main objective of these experiments was to study the violation of the K selection rule for electromagnetic transitions in nuclei. The absolute transition probabilities in 130 Ba, 132 Ce, 134 Nd, and 184 Pt were measured [23].…”