Nuclear Energy Levels ofNa24in the Region from 350 to 630 kev

Abstract

The neutron cross-section data from 350 to 630 kev show 71 peaks, consisting of a relatively small number of large peaks and many small peaks. Each of the previously known large peaks was resolved into two or more components. The analyses show a few $s$-wave levels, a small number of $p$-wave levels, and a large number of $d$- and $f$-wave levels. For all of the levels of ${\mathrm{Na}}^{24}$ up to 630 kev, a plot of the number of levels having energies $\le E_n$ as a function of the neutron energy $E_n$ shows an essentially linear distribution. The distribution of the angular momenta is in agreement with the theoretical distribution for a value of $\sigma =1.8\mathrm{}$. The level spacings appear to agree with an exponential distribution. For the reduced neutron widths, the results appear to agree equally well with the exponential and Porter-Thomas distributions. The strength function obtained from the reduced widths has an average value of 0.045 for both values of $J$ for $l=0\mathrm{}$ and an average value of 0.37 for all values of $J$ for $l=1\mathrm{}$. For higher values of $l$, the strength function is too large. An expression developed for the distribution of the levels above the ground state tends to agree with the data for a value of 0.50 Mev for $\delta$, the average level spacing of the nucleons in the nucleus.