Neutron capture inTe122,123,124: Critical test forsprocess studies

The neutron capture cross sections of ${}_{}{}^{122,123,124,125,126}{}_{}{}^{}\mathrm{Te}$ were measured in the energy range from 10 to 200 keV at the Karlsruhe Van de Graaff accelerator using gold as a standard. Neutrons were produced via the ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$(p,n${)}^7$Be reaction by bombarding metallic Li targets with a pulsed proton beam. Capture events were registered with the Karlsruhe 4π barium fluoride detector. Several sets of measurements were performed under different experimental conditions to study the systematic uncertainties in detail. The cross section ratios σ(Te)/σ(Au) were determined with an overall uncertainty of ∼1%. This is an improvement by about a factor of 5 compared to existing data. Maxwellian-averaged neutron capture cross sections were calculated for thermal energies between kT=10 and 100 keV by normalizing the cross section shape up to 600 keV neutron energy reported in literature to the present data. These stellar cross sections were used in an s process analysis. With the classical approach the abundances of the three s only isotopes ${}_{}{}^{122,123,124}{}_{}{}^{}\mathrm{Te}$ could be reproduced within the experimental uncertainties of ∼1%. The accuracy of the present data also allowed us to derive constraints for the existing stellar models with respect to the effective neutron density. Furthermore, the p process abundances for the tellurium isotopes are discussed.