Nuclear Spectroscopy with Average Spectra from Neutron Resonance Capture

Methods for the determination of spins and parities of nuclear states by means of measurements of the average $\gamma$-ray spectra formed by neutron capture in many resonances are described. Results for 30 low-energy states of ${\mathrm{Er}}^{168}$ illustrate the use of the average $\gamma$-ray intensity, and measurements on nuclides near $A=100\mathrm{}$ show that the $\gamma$-ray line shape can also provide valuable information.