From abstract: "A fine-grain emulsion has been found which is sensitive only to the densely ionizing fission fragments. This emulsion was soaked in uranyl acetate and exposed to slow neutrons. The ranges in the emulsion of about four-hundred fission fragments were measured. The resulting distribution shows a sharp maximum at 23 microns of emulsion. No ternary fissions or large-angle scattering of fragments were observed."

From abstract: "A theory of the sublimation of solids is presented and compared with experimental data on UCl4."

This technical report consists of day by day experimental data reported in Engineer's Log book, Electro-Chemistry Department, supporting Report No. EC-11 dated November 15, 1944, by W. L. Grube, Research Laboratories Division, General Motors Corporation.

This technical report contains day by day experimental data reported in Engineer's Log Book, Electro-Chemistry Department, supporting Report No. EC-11 dated November 15, 1944, by W. L. Grube, Research Laboratories Division, General Motors Corporation.

This technical report details a process in order to determine the densities of several uranium compounds.

From abstract: "Frequently it has been desirable to prepare pure anhydrous metal fluorides. Several general methods have proved satisfactory depending on the type of fluoride to be prepared."

Abstract: Although we are generally interested in nuclear resonance levels, our measurements on Mn55 (naturally occurring Mn is 100 percent Mn55) were undertaken in order to corroborate Goldhaber's discovery of an extremely large scattering by this element.

A method is described to record the rise in intensity of any hard neutron radiation end to cut off the radiation at any predetermined level.

From introduction: "These data were taken on a 1/16th scale model of the magnet shown on sketch no. FS-2. The object of these measurements was to get information that would determine the final design of the full scale magnet. The one main point to be settled was whether a tapered or a cylindrical pole piece would give the largest value of Hρ for a given power input into the magnet (the cylindrical pole piece is shown in dotted lines in sketch FS-2)."

From introduction: "The Boltzmann equation expressing conversation of particles in phase space is set up."

The study was conducted to ascertain the maximum amount of uranyl carbonate that could be held in solution at equilibrium in either water or various salt solutions

Methods based on alpha activity measurements have been developed for the determination of small amounts of uranium in solution, and these methods have been applied to the determination of the solubility of uranous oxalate under a variety of conditions.

A summary of certain reactions of uranium metal is presented.

Abstract: The purpose of this research was to obtain data that would be useful in predicting changes that might be expected to occur in the oxidation state and degree of hydration of powdered uranium oxides maintained for long periods of time at temperatures between 30 and 300 degrees C. in the presence of excess water, hydrogen, oxygen and possibly hydrogen peroxide. The reaction of hydrogen and oxygen with water slurries of U3O8 were studied at 100-300 degree C.

Technical report discussion of the complicated problem of the spatial distribution of slowed down neutrons. The introduction covers the current research on the topic. The following chapters cover the topics: (1) approximate treatment and its limitations, (2) age-velocity distribution, (3) general scheme of treatment based on transport equation, (4) Fermi's one-dimensional model, (5) moments, (6) remarks about the distribution function, and (7) point source.

From introductory paragraph: "In a slightly hypocritical water boiler the introduction of a single neutron may give rise to a fairly large burst of neutrons which dies out slowly. As was shown some time ago by Frankel and Nelson with the help of A. Horn the statistics of this multiplication process can be treated in a simple way for the hypothetical case that the number of neutrons produced per fission is two."

Evidence is presented indicating that both acute and chronic radiation anemia are due, in part, to a hemolytic reaction, and not solely to an inhibition of erythropoietic activity as has been assumed by most investigations.

Abstract: The counting accuracy of the Chicago Scalers, Models 961A and 961B, is a function of the bias setting of the limiter (V2). this report gives quantitative data supporting this thesis. A method of making bias settings is suggested. These tests were run at the suggestion of Mr. V. C. Hanson.

Technical report describing development of the Clinton alpha amplifier. The circuit for the Clinton alpha amplifier which is used with an Offner scaler is shown attached to the report. It consists of a pre-amplifier mounted in a cylindrical alpha chamber, followed by a three state amplifier and a pulse height selector in a separate cabinet. Pulses are fed from the pulse height selector in the amplifier to the input tube of the Offner scaler. Through the third stage of the amplifier, this circuit is exactly the same as the California circuit now used by the chemical section for alpha counting. A type 961 Offner scaler was used for these tests. None of the latest Offner scalers type961A, were available to us when the tests were made. Method of testing is given, results are tabulated, computations are made, and eight graphs are given. it appears that the Clinton amplifiers used with a Offner scaler will give substantially the same performance as that given by the California circuit.

From abstract: "A control rod absorbs neutrons and increases the leakage of neutrons from the pile through the depression of the neutron density in its vicinity. To determine the effect of controls on critical conditions for a pile the absorber may be considered, as in the electrical analogue, to produce a singularity in neutron density at its position. The strength of such a singularity is determined by the boundary conditions which must be satisfied at the surface of the black or non-black absorber and the order of the singularity is determined by the geometry of the problem. The general solution of the pile equations can then be expressed by a sum of a regular solution plus the solution containing the proper singularities and this total solution can be adjusted to satisfy the boundary conditions. By this means the effect of control rods of various sizes and positions on pile reactivity and neutron distribution and the effects of mutual control rod shading have been investigated both by a thermal and by a two group theory."

From introduction: "The measurement of the thermal conductivity of liquid TF6 presented unusual difficulties because of two of its properties which necessitated working with a closed system. The properties were (1) the liquid can exist as such only above 64.05°C. at which temperature its saturated vapor pressure is 1140 mm. of mercury, and (2) the compound reacts rapidly with moist air. Also because of the liquid's extremely corrosive nature, it was necessary to design a cell of special corrosion resistant materials."

Introduction. The main objective of the Metallurgical Project was the preparation of large quantities of plutonium 239, an isotope of element 94, by the interaction of neutrons and uranium. At the beginning, only predictions of its chemical and biological properties could be made since it is a new element. It was predicted that it would be toxic to tissue by virtue of its high atomic weight, and in addition, that it would be toxic by virtue of its radioactivity. Thus, the preparation and use of the element on a large scale meant the manipulation of, and possible exposure to, toxic quantities. It was, therefore, of practical importance to obtain data which would elaborate on the predicted toxicity. The objectives of the work reported here were to establish the acute toxicity of plutonium in experimental animals and to study the distribution of the element in the body after the administration of a wide range of doses. In the interest of economy of what was, at that time, a rare substance, and of animals and facilities, these two objectives were frequently pursued in the same experiment. The information obtained from the separate experiments is therefore frequently incomplete in one or another respect. …

This article covers investigations carried out on an ultramicrochemical scale with volumes from 0.1 to 0.5 of a microliter and 0.5 mg of plutonium being used.

This paper is to develop the theory of the unsteady-state behavior of these cascades and to present simple ways of thinking about this behavior