Neutron Resonance Spectroscopy on 209Bi

Abstract

The neutron transmission through 209Bi was measured with high resolution at both the 80 and 200 m stations of the Oak Ridge Electron Linear Accelerator. Resonance parameters for s-wave levels below 270 keY and for p-wave levels below 100 keY bombarding energy were obtained. Approximately 25 % of the expected neutron strength of a particle-vibrator doorway was identified in the energy range analysed for s-wave resonances. The average s-wave level spacing is s = 4·5 ± 0·6 ke V after correcting for missed levels. The s- and p-wave neutron strength functions are respectively: 104 So = 0·65 ± 0·15 (E < 170 keY); 104 Sl = o· 25 ± 0·07 (E < 60 keY). Both strength functions show evidence of energy-dependent structure.