Slow-Neutron Resonances inEu151andEu153

The total neutron cross sections of ${\mathrm{Eu}}^{151}$ and ${\mathrm{Eu}}^{153}$ have been measured between 1 and 10 ev using a high-resolution crystal spectrometer. The Breit-Wigner parameters have been obtained for the 1.055, 2.717, 3.368, and 3.710-ev resonances in ${\mathrm{Eu}}^{151}$, and for the 1.725, 2.456, 3.294, 3.944, 6.16, and 8.87-ev resonances in ${\mathrm{Eu}}^{153}$. The values of the radiation widths for the 1.055, 2.717, 3.368, and 3.710-ev resonance in ${\mathrm{Eu}}^{151}$ are almost identical, whereas out of the six resonances in ${\mathrm{Eu}}^{153}$ five are almost identical, and one is about 30% higher.