In an elastic collision the neutron loses part of its kinetic energy to the nucleus with both the kinetic and momentum of the system being conserved. However, for many elements the scattering is not isotropic in the center-of-mass system at the higher neutron energies. Many of the present reactor multigroup codes include anisotropic scattering at the high neutron energies, while many others assume isotropic scattering at all energies. In order to consider some of the effects of including anisotropic scatting, reference is made t the multigroup equation generally assumed for the slowing-down density.

The information concerning beryllium assembled herein has been selected primarily to provide information that might be pertinent to the design of the ART. The creep-rupture data in the literature have been obtained from vacuum cast and extruded beryllium, rather than from the hot-pressed beryllium which will be used in the ART. A research program is being conducted by the Brush Beryllium Company, under contract to the Oak Ridge National Laboratory, which will eventually provide the design engineers with data on the high temperature strength properties of hot-pressed beryllium. In the interim, it will be necessary for the metallurgists and design engineers to make judicious estimates and extrapolations from the data available.

Fused uranium dioxide has desirable characteristics for fabricating high density nuclear fuel elements by swaging. Methods of preparing dense uranium dioxide particles being investigated at HAPO include are arc fusion, and sintering and crushing of low density powder. This paper reports the results of exploratory experiments to prepare fused uranium dioxide by induction heating of low density powder in graphite crucibles.

A report which discusses the data submitted for evaluation. This data is about optical densities from infrared spectrometer readings on eight standard samples, ranging in percent TBP from 6.71 to 17.85.

Abstract: "The possibility of transient temperature variations during the self-heating of a plasma by thermonuclear reactions was investigated. Calculations were performed on an IBM Card Program Calculator. Estimates of the time scale for self-heating were obtained. It was concluded that it would be unsafe to assume that the nuclear temperature is always equal to or greater than the electron temperature in a discussion of plasma instabilities for a plasma with 10 percent or greater tritium concentration."