Levels of 56Ni from the reaction 58Ni(p,t)56Ni at 28 MeV

Mass measurements for nuclear astrophysics with JYFLTRAP

“…Excluding 53 Co, the uncertainties of the mass excess values have been reduced below 1 keV. The new JYFLTRAP value for 56 Ni agrees with all previous experiments [27,[35][36][37] but is 26 times more accurate than the adopted value in the AME2003 [27]. In addition to the mass excess values, Q EC values for 53 Co, 53 Co m , 55,56 Ni, 57,58 Cu and 59 Zn have been directly measured using the beta-decay daughter as a reference.…”

Mass measurements in the vicinity of the doubly magic waiting pointNi56

“…FIG. 5: Differences between the experimental mass excess values of the nickel isotopes measured at JYFLTRAP with respect to the earlier experiments [32,[35][36][37][38][39][40] and AME03 [29].…”

“…The current mass excess value of 56 Ni is based on the Q values of the reactions 58 Ni(p,t) 56 Ni [38] and 54 Fe( 3 He,n) 56 Ni [39]. Recently, prompt proton decay (E p = 2540(30) keV) was observed from a level at 9735(2) keV in a rotational band of 56 Ni [40].…”

The origin of the elements

“…Thus even when experimental information is available it usually has to be extrapolated to low energies while in two of the nuclear processes, e and r, many important nuclides are ones for which little information is available. The theory of the e process has been considerably improved recently by the first accurate measurements of the binding energy of doubly magic i:Ni, the most strongly bound a-particle nucleus (Hoot et al 1963, Miller et al 1963. I n the r process, nuclei far on the neutron-rich side of the stability line may be of importance and information is required both on their binding energies and on their cross sections for neutron reactions.…”