The following report calculates how many neutrons are produced by the O-16([alpha]-n) reaction in a thin and uniform polonium oxide layer.

Abstract: "A theoretical and experimental investigation is made of the diffraction pattern produced by a slit, whose aperture varies uniformly from a constant value A to zero. The results of this investigation are applied to a proposed high speed camera. It is shown that diffraction effects are very serious and cannot be neglected. It seems, unless the suggested design of this high speed camera is changed, the camera will be of little use for accurate measurements, and photographs will show too much blue to give details."

"This report gives briefly a rather simple method for fabricating foils from uranium buttons. Two log sheets one of a U-238 run and one of a U-255 run are given."

Abstract: "This report describes work done to improve the casting characteristics of methyl methacrylete resin under CMR-6-18 authorization. The experimental program was initiated with the objectives of decreasing casting time, bubble formation and shrinkage. It has been found that by use of a common solvent for monomer and polymer concentration in monomer can be attained greater than any previously reported in preparation of a methacrylate casting resign. Incorporation of this greater amount of polymer has produced the desired effects. A bibliography of relevant literature is included to which reference is made in the text."

From abstract: "The present report describes experimental work performed to establish a procedure for the production of uranium metal wire. In all cases, the size of the initial rod was 1/2 inch diameter. Three materials were used: hot extruded tuballoy rod, high purity cast tuballoy rod, and cast U-235 rod."

The following report examines the fission counter, fission plates and activation results of the neutron energy distribution in the center of the Los Alamos plutonium reactor.

The operation of the Fast Reactor is considered in terms of normal equilibrium conditions and normal shut-down. The proposed loading, control rod adjustment and subsequent "floating" operation are discussed. Safety devices and interlocks are described. Temperature and reactivity changes are examined with respect to various system failures, phase changes, and "flashing" of the reactor. Slow changes due to faulty slug cooling are also considered. The calculations were initially based upon 10 kw operation. Performance tests of the mercury system now indicate that 20-kw operation may be feasible.

This report records two samples of Xe-135 that have been isolated with activities sufficient for the measurement of the cross section of Xe by the velocity spectrometer technique.

The following report describes procedures taken to utilize the photelometer to procure the most rapid and reliable determinations, but the goal of the tests presented was to create satisfactory dispersions of particles to analyze.

This is a summarizing and reviewing report in which almost all the experimental data representing Project work done prior to 1949 on the corrosion of pure uranium are brought together and analyzed. New data obtained in this laboratory on corrosion rates in laboratory atmosphere and on the identification of corrosion products by electron diffraction are included. The data for corrosion in each of several different media have been plotted according to logarithm-of-the-rate versus reciprocal-temperature coordinates; and from these plots values for the energies and entropies of activation of the corrosion reactions have been obtained. By theoretical treatment of the role of oxygen as a negative catalyst, it is shown that this element may be expected to "poison" the corrosion rection and then act as a corrosion inhibitor. A practical significance of these data analyses is that they explain why machined uranium parts stored in inert atmospheres (helium or argon) containing only very small amounts of water vapor will corrode relatively rapidly with the formation of loose powdery oxide, whereas similar parts may be kept in dry air almost indefinitely with formation on their surface of only a discoloring, but adhered, oxide coating.