Reduction in the uncertainty of the neutron-capture cross section of Bi-210: Impact of a precise multipolarity measurement of the 2(-) -> 1(-) main ground-state transition

The mixing ratio of the main 320-keV, M 1 + E 2 ground-state γ transition in 210 Bi has been more precisely quantified, allowing a significant reduction in the uncertainty of measurements of the neutron-capture cross section to the ground state of 210 Bi from 25% to 0.9%. Accurate values for neutron-capture cross sections to both the ground and long-lived 9− isomeric state at 271 keV in 210 Bi are of particular importance as Pb-Bi finds increased usage in Accelerator Driven Systems.