Abstract. A review of all work on uranium hydride published in the CC, CT, CN and CE reports to January 1, 1944, is presented. Some additional information not yet published has been included, so this report includes all data known from the above sources and at Ames to the above date. This report supersedes all previous report on uranium hydride coming out of the Ames laboratory.

Technical report describing a gasometrical method for the determination of H2 in extruded U rods.

Technical Report: A generalized review of the chemical problems and researches related principally to the heavy water homogeneous pile is presented herewith. The report covers researches performed principally by the Columbia Group who initiated the study. This report contains a chronological outline of the development, a discussion of some special topics whose significance is paramount in any slurry pile discussion, and finally an outline of important research problems remaining, roughly graded in order of their importance. No attempt has been made to be either complete or detailed in the discussion. The emphasis has been principally on furnishing a broad guide to those who may t some future date take up this work.

Technical report. Areas covered are properties of uranium halides, properties of uranium nitrides, and hydride formation at high pressure.

Technical report describing the investigation of the short-lived activities produced in oxygen compounds by irradiation with pile neutrons. The most prominent of these activities in cooling water is a beta and gamma emitting activity of about 8 second half-life. Because of its production by epicadmium neutrons it was believed to be the 8 second N16 produced in the pile by n,p on O16. The identification has been accomplished and it is established that the 8 second activity is N16. Part 2 of the report deals with the determination of the recoil range of the Al28 atoms formed by pile n,p reaction on Al27.

Technical report. Long-time tests have been made on the effect of various types of radiation on the corrosion of 2S aluminum in simulated W water. In no case was any acceleration of corrosion by the radiation observed; the effect of radiation, if any, appeared to be a protective one. Deuteron irradiation did accelerate the corrosion of mild steel at low flow rates in hot water of pH 6 to 7, but no appreciable effect was observed with copper, stainless steel, or tuballoy. The general theory of the effect of radiation on corrosion is discussed, with the conclusion that no acceleration of corrosion by radiation is to be expected in most cases of practical interest.

Technical report. The extent of the Wigner effect in graphite at any point in a pile is sensitive to the local structural situation. It is greater near a slug. These control experiments give information on changes in graphite to be expected in selected places in the pile.

Technical report containing short reports on (1) Mass spectrometer studies; (2) Purification of heavy water; and (3) Equilibration studies.

Technical report abstract. A rapid procedure for the preparation of very pure carrier-free Zr and Nb tracer involves the chloroform extraction of the cupferrides of Zr and Nb activities from process solutions. Zr and Nb form very stable chloroform soluble cupferrides in acid solutions (CK-993) and are separated from other fission elements almost quantitatively to yield pure mixture of Zr and Nb activity. A minimum of operations is required and the method is easily adaptable to remote control.

Abstract: Experiments on colloid milling and pumping show that uranium trioxide, when carefully dehydrated, can be dispersed in water to form a relatively stable slurry, suitable for a homogeneous slurry pile. At temperatures considerably below those of anticipated pile operation particle size growth occurs attended by increase in settling rate and decrease in viscosity. Theses properties of the slurries may be strongly affected by impurities present as well as by special operating conditions.

Abstract. the electrodeposition of uranium metal, in the form of tree-like deposits, from molten strontium halide baths is described. Under the best conditions studied, approximately 40% recovery is attained. Freedom from side-reactions of the reduced uranium with anode products and/or refractory materials, and high cathode current densities appear to be essential to the success of the process. the refining of uranium under similar conditions appears to occur quite readily, with approximately 50% current efficiency. The preparation of UI3 is also described.

Abstract. Wigner effects on aluminum, beryllium, and tuballoy have been studied by the electrical resistance method. Samples were exposed during an interval which would have produced an increase of approximately 22% in resistance of AGOT-K graphite. The resistance of tuballoy increased approximately 1%. It is shown that the increase can be accounted for by the amount of fission product impurity formed during the exposure. Neither aluminum nor beryllium showed any change. In the case of Be, the Wigner effect may be obscured, to some extent, by the approximately .2 - .3 atom % of impurity present in the samples. Based on the increase occurring in ADOT-K graphite, a change of approximately .2 - .5 x10-6 ohm-om might be expected in the case of Be. The accuracy of the method was sufficiently great to detect a change of this magnitude. Other experiments with Be will be undertaken when purer samples are available. Meanwhile, some samples of the present type ae being subjected to further irradiation.

Abstract. A portion of the liquid-solid phase equilibrium region of the system U-UBr3 has been investigated by the method of thermal analysis. Uranium tribromide was prepared by introducing bromine vapor into a bulb containing finely divided uranium formed from the hydride. Cooling curves were obtained with tribromide and then with various compositions of tribromide and uranium. the information obtained showed that no solid sub halide exists but that the metal was soluble in the halide.

Abstract: An ionization chamber for use in counting alpha particle activity from the air has been devised for counting samples collected with the electrostatic precipitator. The chamber is an adaptation of the breech-locking standard chamber, with a cylindrical high voltage electrode into which the collection foil is placed, and a coaxial rod as a collecting electrode. A geometrical efficiency of close to 50% is obtained.

Report detailing values of x-ray lives and limits for trans-uranic elements. Formulas and methods are detailed throughout the report.

Introduction: Measurements of polonium content in solids are usually performed by dissolving the material and preparing a thin sample which can be measured with one of the available instruments. A measurement of the radiation emerging from the thick sample should be sufficient to evaluate the polonium content. For this reason a calculation has been performed and the results have been compared with those obtained by the thin sample method. Obviously this proposed method using thick samples would be faster.

From introduction: "You will find enclosed the specifications for the freezing point method for determination of the amount of HF in UF₆. The specification for cleaning new shipping containers is also included."

The following report describes and foretells the situation in medium in which neutrons are being (a)produced as fast neutrons, (b) slowed down to thermal speeds by impacts with nuclei, and (c) absorbed by nuclei in such a manner that sometimes fresh fast neutrons appear at the place where a thermal neutron has just appeared.

A report which investigated vacuum distilation, entrainer gas distillation, and entrainer gas plus bromine vapor distillation.

Report discussing an experiment in which films of boron were deposited on glass and on metals by the thermal deposition of diborane at tempertatures between 500 and 600°C.

Abstract: "For defects between interior and coating, or between successive layers of coating, a simple, fairly accurate formula is established. The temperature rise at the edge of the defect is briefly discussed."

Abstract: "The behavior of radially split hollow cylinders upon heating is discussed."

The following report describes tests made for the purpose of determining the accuracy and permanency of various types of high resistance bleeders, and their resistance variation during use over a period of approximately six months.

Abstract: "Photographic plates have been used to measure the energy of neutrons from the fission of 25. The spectrum as inferred from the ranges of 850 protons recoiling in the forward direction shows a very wide maximum at ~1.5 Mev with an exponentially decreasing high energy tail which extends beyond 7 Mev. The minimum energy neutrons recorded were ~700 kv. If the spectrum is extrapolated to zero, one finds that this average neutron energy is about 1.85 Mev. The stopping power of the plates was calibrated by the use of monochromatic neutrons from the Li-7(pn) Be-7 reaction and the d-d reaction."