"Time of flight spectrometers for the study of neutrons emitted in charged particle reactions have become important in recent years, following the development of suitable photomultiplier tubes and electronic circuits for nanosecond (ns) timing measurements. The principle of operation is simple. The particles exciting the nuclear reactions in which the neutrons are produced fall on the target in bunches of the order of a nanosecond in width. the arrival of product neutrons at a organic scintillation counter (proton recoil) detector placed a few meters from the target gives signals which can be used to determine the flight time of the neutrons from target to detector. A time-reference pule corresponding to the arrival of beam pulses at the target is required."

"Investigations into the behavior of the gas flow behind spherical or cylindrical blasts have shown that secondary shocks arise within the original detonation gases. The secondary shock, at first weak, is carried outward with the expanding gases. Subsequently it strengthens and bends back toward the origin, arriving there with high intensity. By using some recently developed techniques in shock dynamics a theory is developed by which the motion of the main shock wave, as well as the formation and subsequent motion of the secondary shock, are given by explicit formulae."

"The lifetimes of approximately 6 million positive mesons have been measured using a crystal controlled oscillator as a clock. The resulting decay curve was analyzed on the IBM 650 digital computer and gave a mean life of 2,211 plus or minus 0.003 µsec. The mean life of negative mu mesons in carbon was also measured and found to be 2,043 plus or minus 0.003 µsec. The resulting nuclear capture rate is (0.373 plus or minus 0.011)x10 to the 5th/sec, assuming that the decay rate of a negative mu meson bound in carbon is equal to the decay rate of the positive meson."

"This is the first quarterly report on Task II of the subject Utilization of Radioactive Isotopes in Coal Process Research. There were two separate projects on Tank I; I. methods Development for Tritium Labeling of Coal Product Hydro-carbons, and II. Applications of Radio-Tracer Techniques to the Study of Fluidized Particle Mechanics. The following extended work on Task II concerns only Methods Development of Radio-Tracing With Tritium."

"The visible absorption spectra of VA3, CrA3, MnA3, FeA3 and CoA3 (A=C5H7O2, the acetylacetonate anion) are reported. The interpretation of the data in respect to the symmetry and strength of the ligand fields is discussed, with special attention to the presence and magnitudes of trigonal components in ligand fields and its consistency with certain results of paramagnetic trigonal fields of appreciable magnitude are present."

Nuclear processes are random in character, and, accordingly, are amenable to statistical treatment. In 1905, shortly after the discover of natural radioactivity, E. Von Schweldler showed that the analytical description of the decay distribution of radioactive substances followed from probability considerations regardless of the mechanism involved in the process of atomic disintegration.

Tests were conducted to determine the friction factor of randomly packed beds of 3/4-inch diameter spheres in 8-inch and 15-1/4-inch diameter beds, and of 1-1/2-inch diameter spheres in 15-1/4-inch diameter bed. The bed depths were varied in an attempt to isolate the effects of entrance and exit losses. The bed Reynolds number, base on sphere diameter, was varied from 5,000 to 50,000.

A program has begun embodying a study of the diffusion rates of krypton and xenon into unirradiated UO2 and UC at temperatures between 1000°C and 2500°C.The experimental technique is described in some detail, involving exposure of UO2 and UC samples to a Kr85 atmosphere at various temperatures, removal of surface-adsorbed krypton, dissolution of the sample, collection and ion chamber measurement of the diffused Kr, and calculation of diffusion coefficients from these data.