Nuclear Properties of93237

The isotope ${\mathrm{Np}}^{237}$, produced as the decay product of the previously known 6.8-day ${\mathrm{U}}^{237}$, has been isolated with carrier material and some of its nuclear properties measured. The ${\mathrm{U}}^{237}$ was formed by means of the reaction ${\mathrm{U}}^{238}\mathrm{}(n,2n)\mathrm{}{\mathrm{U}}^{237}$. ${\mathrm{Np}}^{237}$ decays with the emission of alphaparticles with a half-life of about ${3\times 10}^6$ years. It has been shown that the upper limit for the cross section for the fission of ${\mathrm{Np}}^{237}$ with slow neutrons is less than 1 percent of that of ${\mathrm{U}}^{235}$.