G. G. Slaughter

Low-energy neutron resonances inPb206

Neutron resonance reactions on an enriched /sup 206/Pb target have been studied below 50 KeV using neutron time-of-flight techniques. The neutron and radiation widths of seventeen resonances were obtained from transmission and capture cross section measurements. Spin and parity assignments for eight resonances were made on the basis of the transmission measurements and the decay patterns of ..gamma.. rays measured with a Ge(Li)detector. The ..gamma..-ray spectra are strikingly simple, being composed of less than five primary ..gamma.. rays. The neutron separation energy for /sup 207/Pb was determined to be 6738.2 +- 0.7 KeV. The magnetic dipole transitions from several p-wave resonances to the first three excited states in /sup 207/Pb show some enhancement. A possible doorway state in the p/sub 1/2/ neutron channel has been observed in the /sup 206/Pb + n reaction at E/sub n/ approx. = 36 keV.

Capture γ-Rays and Reaction Mechanism in 100Mo + N

Capture γ-ray spectra from 11 resolved resonances in Mo-100 + n have been measured at a 10 m flight path of the Oak Ridge electron linear accelerator time-of-flight facility. Contrary to neighbouring nuclei, partial radiative widths of strong p-wave resonances are not in agreement with valence model predictions.

Low-energy neutron resonances in Pb-206

Neutron resonance reactions on an enriched /sup 206/Pb target have been studied below 50 KeV using neutron time-of-flight techniques. The neutron and radiation widths of seventeen resonances were obtained from transmission and capture cross section measurements. Spin and parity assignments for eight resonances were made on the basis of the transmission measurements and the decay patterns of ..gamma.. rays measured with a Ge(Li)detector. The ..gamma..-ray spectra are strikingly simple, being composed of less than five primary ..gamma.. rays. The neutron separation energy for /sup 207/Pb was determined to be 6738.2 +- 0.7 KeV. The magnetic dipole transitions from several p-wave resonances to the first three excited states in /sup 207/Pb show some enhancement. A possible doorway state in the p/sub 1/2/ neutron channel has been observed in the /sup 206/Pb + n reaction at E/sub n/ approx. = 36 keV.

Low-energy neutron resonances in /sup 206/Pb

Neutron resonance reactions on an enriched /sup 206/Pb target have been studied below 50 KeV using neutron time-of-flight techniques. The neutron and radiation widths of seventeen resonances were obtained from transmission and capture cross section measurements. Spin and parity assignments for eight resonances were made on the basis of the transmission measurements and the decay patterns of ..gamma.. rays measured with a Ge(Li)detector. The ..gamma..-ray spectra are strikingly simple, being composed of less than five primary ..gamma.. rays. The neutron separation energy for /sup 207/Pb was determined to be 6738.2 +- 0.7 KeV. The magnetic dipole transitions from several p-wave resonances to the first three excited states in /sup 207/Pb show some enhancement. A possible doorway state in the p/sub 1/2/ neutron channel has been observed in the /sup 206/Pb + n reaction at E/sub n/ approx. = 36 keV.

Enhanced Primary M1 Transitions in 207Pb

The neutron resonance reactions on an enriched 206Pb target have been studied below 50 keV using neutron time-of-flight techniques. The Ml transitions from several p-wave resonances to the lowest three states in 207Pb show some enhancement.

Correlation of the Primary Gamma-Ray Intensities Following s- And p-Wave Neutron Capture in 58Fe

In the (n,γ) reactions with low-energy neutrons, the partial radiation widths from adjacent resonances are almost always uncorrelated with each other. However, in a recent study of the 35Cl(n,γ)36Cl reaction, Chrien and Kopecký1 found similar γ-ray spectra from neighboring capture states of opposite parity. Expressed as a linear correlation coefficient, these authors found r = +0.84 −0:10 +0.06 for a set of 14 transitions seen in both s-wave thermal capture and in p-wave 398-eV resonance capture in 35Cl.