High-resolution neutron capture cross sections inCu63andCu65. II

Neutron capture cross sections in separated isotopes of copper (${}_{}{}^{63}{}_{}{}^{}\mathrm{Cu}$ and ${}_{}{}^{65}{}_{}{}^{}\mathrm{Cu}$) from a few keV to a few hundreds of keV were measured. From these measurements the capture yields of resonances were accurately determined, giving precise values of $g{\Gamma }_n$ and ${\Gamma }_{\gamma }$ up to a maximum neutron energy of 50 keV. For ${}_{}{}^{63}{}_{}{}^{}\mathrm{Cu}$ one obtains a value of $〈{\Gamma }_{\gamma }〉=490\mathrm{}\pm 30$ meV, $p$-wave average level spacing ${〈D〉}_{l=1\mathrm{}}=0.495\mathrm{}\pm 0.026$ keV, and strength function $S_1=(0.44\mathrm{}\pm 0.07)\times {10}^{-4\mathrm{}}$ e${\mathrm{V}}^{-\mathrm{½}}$. For ${}_{}{}^{65}{}_{}{}^{}\mathrm{Cu}$, one obtains a value for $〈{\Gamma }_{\gamma }〉=385\mathrm{}\pm 20$ meV, ${〈D〉}_{l=1\mathrm{}}=0.685\mathrm{}\pm 0.060$ keV, and $S_1=(0.47\mathrm{}\pm 0.08)\times {10}^{-4\mathrm{}}$ e${\mathrm{V}}^{-\mathrm{½}}$. The corresponding $s$-wave mean level spacings for ${}_{}{}^{63}{}_{}{}^{}\mathrm{Cu}$ and ${}_{}{}^{65}{}_{}{}^{}\mathrm{Cu}$ are 1.04±0.11 and 1.47±0.19 keV, respectively. Some few of the narrowest levels have been assumed formed by $d$ waves.