Kinetic Energy Release in 23-MeV Deuteron Fission ofU238

Average recoil ranges have been measured for six fission products formed by reactions of 23-MeV ${\mathrm{H}}^2$ with ${\mathrm{U}}^{238}$. The ranges of products from near-symmetric fission (${\mathrm{Cd}}^{115}$ and ${\mathrm{Ag}}^{111}$) are longer than for neutron fission of ${\mathrm{U}}^{235}$, while the ranges of asymmetric products (${\mathrm{I}}^{131}$, ${\mathrm{Ba}}^{140}$, ${\mathrm{Mo}}^{99}$, and ${\mathrm{Sr}}^{89}$) are shorter. The kinetic-energy deficit for near-symmetry fission is 15±6 MeV smaller for this system than for thermal-neutron fission of ${\mathrm{U}}^{235}$. The magnitude of the kinetic-energy deficit for ${\mathrm{U}}^{236}$ fission is re-examined by comparing range data with recent time-of-flight measurements and neutron emission probabilities. This comparison leads to a kinetic-energy deficit of approximately 23 MeV for ${\mathrm{U}}^{236}$ fission.