Cross-section measurements were made of prompt gamma-ray production as a function of incident neutron energy (E{sub n} = 1 to 35 MeV) on an enriched (95.6%) {sup 150}Sm sample. Energetic neutrons were delivered by the Los Alamos National Laboratory spallation neutron source located at the Los Alamos Neutron Science Center (LANSCE) facility. The prompt-reaction gamma rays were detected with the large-scale Compton-suppressed Germanium Array for Neutron Induced Excitations (GEANIE). Neutron energies were determined by the time-of-flight technique. The {gamma}-ray excitation functions were converted to partial {gamma}-ray cross sections taking into account the dead-time correction, target thickness, detector efficiency and neutron flux (monitored with an in-line fission chamber). Partial {gamma}-ray cross sections were predicted using the Hauser-Feshbach statistical reaction code GNASH. Above E{sub n} {approx} 8 MeV the pre-equilibrium reaction process dominates the inelastic reaction. The spin distribution transferred in pre-equilibrium neutron-induced reactions was calculated using the quantum mechanical theory of Feshbach, Kerman, and Koonin (FKK). These pre-equilibrium spin distributions were incorporated into a new version of GNASH and the {gamma}-ray production cross sections were calculated and compared with experimental data. The difference in the partial {gamma}-ray cross sections using spin distributions with and without pre-equilibrium effects is discussed.

Neutron Cross Sections, Volume 2: Neutron Cross Section Curves presents data for total reaction cross sections and related fission parameters as a function of incident-neutron energy. This book covers energy range from 0.01 eV to 200 MeV to exclude crystalline and magnetic effects for slow neutrons and relativistic effects for high energy neutrons. The data in this volume are grouped into sections corresponding to the element of the target nucleus in the neutron-induced reaction. These sections are ordered in increasing atomic number. Within a section, graphical data are presented for the natural element followed by the isotopes of that element in order of increasing atomic mass. A list of the reaction types is provided at the end of each section. This book also provides graphical section, wherein each graphical page is annotated on the outer edge with a symbol for an element or isotope followed by the list of the cross section data for that element or isotope. The data plotted in the graphical section are tagged by a mnemonic consisting of year, laboratory, and author's last name. This tag can be used to find the corresponding reference on the bibliographic pages.

The total cross sections of twelve different elements were measured using the neutron beam from the 184-in. cyclotron, operating with deuterons. Bismuth fission ionization chambers were employed as both monitor and detector in conventional 'good geometry' attenuation measurements in the neutron flux emerging from the 3-in. diameter collimating port in the 10-ft-thick concrete shielding. The mean energy of detection of the neutrons in this experiment is estimated to be 95 Mev. Measurements were also made with a monitor and detector placed inside the concrete shielding where an intense neutron flux over a large area could be obtained. Attenuators of four different elements were placed in front of the detector in a 'poor geometry' arrangement so that attenuation was due essentially to inelastic collisions which degrade the neutron energy below the fission threshold. A second detector was placed outside the concrete shielding In the collimated neutron beam in line with the neutron source, absorber, and first detector. Attenuation in it is caused by both inelastic and elastic scattering. By this arrangement the ratio of inelastic to total cross section can be determined directly in one experiment. The nuclear radii as calculated from the observed cross section, using the theory of the transparent nucleus, vary as 1.38 x 10(exp-13) A(exp(1/3)) cm. In this energy range the ratios of the inelastic to total cross sections are all less than one-half.