Fission Cross Section of Uranium-234

The neutron-induced fission cross section of U²³⁴ has been measured from threshold to 4-Mev neutron energy, using the $T(p, n)$ reaction with a tritium gas target, and the Oak Ridge 5-Mev Van de Graaff. The curve rises from threshold at 350 kev to 1.3 barns at 4 Mev. There is a minimum at 1.08 Mev and another at 2.30 Mev. These dips are about 13 percent and 7 percent, respectively, of the cross section at these points. Statistics in these regions are sufficient to establish the fact that the minima are real to a probability of 10⁹ relative to a "best fit" curve with no extrema.