Total neutron cross sections of Zr isotopes in the energy range up to 20 keV

Neutron capture cross section ofZr90: Bottleneck in thes-process reaction flow

“…The light output of the detectors was calibrated at 662, 1173, and 1332 keV by means of 137 Cs and 60 Co reference sources. An additional calibration point at 6.13 MeV was obtained by means of a composite 238 Pu/ 13 C source. The calibration was repeated in regular intervals to verify the stability of the detectors and of the data acquisition system.…”

“…Another important aspect is related to the interpretation of the isotopic pattern of Zr observed in presolar grains [7], which provides a test for the s-process efficiency due to the 13 C neutron source reaction.…”

“…Experimental cross sections with uncertainties 3% are necessary for such investigations as well as for comparisons between different AGB models [8]; data of this quality are not available today [1]. Especially the status of the 90 Zr cross section is not satisfactory, because different measurements have reported uncertainties between 6 and 25% but exhibit discrepancies up to a factor of 2 [9][10][11][12][13][14][15].…”

TheZr92(n,γ) reaction and its implications for stellar nucleosynthesis

“…Existing experimental data mainly come from relatively old measurements [8][9][10][11]. Reference [9] lists the energies of the resonances up to 40 keV and gives capture kernels up to 10 keV (with associated errors of between 10% and 20%); Ref.…”

“…[10] lists some resonances (15 of 52 known in this range) up to 52 keV but gives detailed information only for four strong resonances. Reference [11] lists five resonances, but the first one has been recognized as not belonging to 92 Zr. A recent publication [12] does not present the resonance analysis.…”