This technical report covers five areas: (1) High-speed computer program; (2) Mathematical methods; (3) ILLIAC use and operations; (4) IBM 650 use and operation; (5) General laboratory information.

This technical report covers five areas: (1) High-speed computer program; (2) Mathematical methods; (3) ILLIAC use and operations; (4) IBM 650 use and operation; (5) General laboratory information.

The order of magnitude of the non-mesonic to mesonic ratio has been measured for several species of hyper- fragments. With this ratio as well as the branching ratio of the mesonic decays and a determination of the lifetime, it is possible to find the partial decay rates of the various modes. This decay rate should throw light on the influence of nucleons on the strangeness violation in the decay. The effect should be greater for heavy hyperfragments. The difficulty in attempts to measure lifetimes in emulsions is that the mean energy of the hyperfragments products by K mesons and Pions is so low that the moderation time is a very small fraction of the lifetime. Although the stopping power of bubble chambers is considerably less, the spatial resolution of these devices is such that the heavier hyperfragments can not be seen or identified. For these reasons, it seems possible to measure lifetimes of heavy hyperfragments only in emulsions. In an attempt to achieve higher nuclear excitation energies in interactions and correspondingly more energetic hyperfragments, a search has made for hyperfragments produced by heavy primaries from the cosmic rays.

To summarize one finds that for diffusion in a temperature gradient by a vacancy mechanism one must have E(M) < E(F). No such restrictions occur for interstitial diffusion. The spatial vacancy distribution is very nearly the equilibrium distribution if dislocations are present. If no dislocations are present then one could obtain E(M) by measurement of the spatial distribution.

From the point of view of predicting melting behavior of fuel elements containing fission products after 50 percent burn-up, the fuel can be considered to consist of 2000 moles Th, 150 moles U, 55 moles of rate earth metal, 31 moles of Zr, 25 moles of Mo, 20 moles of Rh-Ru-Tc, and 15 moles of alkaline earth metal. All other fission products are present in too small amounts to have any important effect upon the melting point or will have vaporized. However, the presence of alkali metal vapor should be considered.

The quantity and characteristics of fission products in coolant gases due to leaking fuel elements are discussed. It is concluded that the rare gases, the alkali metals, the halides, and Sb may act as permanent gases to a considerable extent. The other fission products are expected to condense out completely on walls or as dust consisting of metals, carbides, and oxides.

The maximum temperature in the interior of the fuel element could be greatly reduced by incorporating a liquid between the fuel element and the outer can to increase-heat transfer rates. It is of interest to consider what liquids would be chemically compatible with graphite and the actinide carbides. Elements which melt below 1100 and boil above 1400 deg C that form no stable solid carbides, include Cu, Ga, TI, Ge, Sn, Pb, Sb, Bi, and compounds include GeP, GeS, GaP, Ga/sub 2/S, GaTe, GaAs, SnTe, Sm/sub 3/As/sub 2/, Sb/sub 3/Te/sub 2/, Zn/sub 3/Sb/sub 2/, Zn/sub 3/P/sub 2/, ZnS, ZnTe, and Zn/s ub 3/As/sub 2/. Some of these compounds have equilibrium pressures that might be considered too high, but they may actually vaporize slowly enough because of low vaporization coefficients to make them suitable. There are probably rot enough data nor adequate theories for predicting the rates, and Langmuir type vaporization experiments would be necessary to determine the rates of vaporization of these compounds. The main problem in the use of a heat transfer fluid is that of reaction between the fluid and the actinide carbides. Thermodynamically extensive attack would be expected. However, it may be possible to make the rate …

From the point of view of constituents of a fuel element at temperatures between 2500 and 4500 degree K, the fuel elements can be considered to consist of six types of material: carbon, elements less volatile than carbon, 26 moles of rare gases, 21 moles of alkali metals, 17 moles of alkaline earth metals, and 4 moles of miscellaneous volatile elements. Various processes involving the constituents from 2000 to 45000 degree K are considered. Reactivity gain due to can rupture is discussed.

Dilute solutions of uranium, thorium, zirconium, and columbium chlorides in LiCl-KCl eutectic melts were made by anodic dissolution of these metals. After equilibrium was reached between the solution and the metal, the electrode potential was measured relative to a AgCl reference electrode. The nature of the metal ions in the equilibrated melt was determined either from the slope of the isothermal plots of potential versus the logarithm of concentrations, or by using Faraday's law. It was found that in the temperature range of 760 to 830 degree K, U3+, Th4+, Zr4+, and Nb3+ are predominant species existing in the uranium chloride, thorium chloride, zirconium chloride and niobium chloride melts respectively. For niobium chloride melts of higher concentrations that that shown above, other species of niobium ions, notably Nb4+, coexists with Nc3+ in appreciable amounts. The results are explained on the basis of the magnitude of the free energy of formation of the chlorides of these metal ions of different valence states and the tendency for these metal ions to form complex ions wit the chloride ions in the melt.

The progress report covers the work carried out during the first year 1958-59 in the department of metallurgy at M.I.T. under the supervision of Professors John T. Norton and Robert E. Ogilvie. A brief summary of the work that has been completed and in some cases still continuing is given. The work has been listed under the following general headings: (1) Diffusion studies in the uranium-niobium system, (2) X-ray detection of cladding defects, (3) Precision X-ray stress analysis of uranium and zirconium, (4) Magnetic studies of Fe3O3 single crystals, (5) Crystal structure studies of yttrium compounds, (6) Structural relationships in ZrFe2-ZrCr2 system.

Molten salts have been used extensively as solvents for electrochemical processes. The difficulty of removing the last traces of residual moisture from the salts has often necessitated rather arduous drying procedures. If the moisture is not removed, hydrolysis occurs upon fusion. The hydroxide ion thus produced precipitates metal ions, attacks glass, and is reduced more easily than the alkali metals, thus diminishing the usable potential range of the solvent. It was found that if rigorously dried hydrogen chloride is bubbled through the melt for twenty minutes before the argon flush, the hydroxide ion impurity is removed.

Classical polarography and voltammetry with other electrodes are discussed . 189 references taken from literature between mid-1957 and mid-to-late 1959 is surveyed.

A method is described for the production of single‐crystal films of copper at temperatures as low as −40°C. This method utilizes the epitaxy of copper on rock salt. A thin layer of copper is evaporated on a single crystal of salt at 350°C. Then a thick layer is evaporated at the low temperature. Films grown by this method have been examined using x‐ray and etching techniques. It was found that some of these films had single‐crystal regions of 1 mm diameter and larger. These crystallites had [100] directions within 1° to a normal to the film surface.

Current regulation of a Bitter type electromagnet powered by a 10 kw. motor-generator set has been achieved by control of the generator exciting field. An error signal, obtained by comparing the voltage drop across a series resistor in the magnet circuit with a reference voltage, is fed back with appropriate amplification to the grids of series tubes in the generator field supply. Magnetic fields from 400 gauss to 10 kilogauss in a fixed gap (1.5 in. width and 3.5 in. diameter) are obtainable with regulation to 3 parts in 104 over the major part of this range.

The potential to kinetic energy conversion process in the lower stratosphere is evaluated using adiabatically derived vertical velocities for the North American region for a five-day period. Preliminary results suggest the possibility that on the average the kinetic energy of stratospheric motions may not result from a conversion of potential energy within the stratosphere. The further implication is that stratospheric motions are mechanically driven by the motions in the adjacent layers of the atmosphere.

A fundamental study is presented comparing the electric properties for materials of "normal" dielectric constant (Al/sub 2/O/sub 3/ and MgTiO/sub 3/) with those of high dielectric constant (TiO/sub 2/, CaTiCO/sub 3/, SrTiO/sub 3/, STABa/sub 0.65Sr/sub 0.35/! STATiO/sub 3/, and BaTiO/sub 3/). Single crystals and ceramics, as far as available, were investigated from d-c to the microwave range as function of time, temperature, field strength, and prehistory. Three types of relaxation spectra were identified, one caused by dipolar groups in unequal double wells, the other two by charge carriers stopped in the volume of the material or in front of the electrodes, respectively, O-H groups in rutile, identified by infrared absorption, seem to cause a dipolar spectrum by thermal excitation leading to hydrogen-bond formation. The shielding of dipoles by countercharges (dipole halos) is probably responsible for the unequal potential wells and likely to be a phenomenon of general importance. Electrons can be injected into rutile and other titanates by field emission. Parallel to the optic axis of rutile, the conduction currents reach especially high values because of an unhampered Ti/sup 3+/ yields Ti/sup 4+/ exchange, and thermal breakdown by field-emission currents occurs. Pure titania materials at high temperatures become very lossy …

Quantitative recovery of carrier‐free 10−9 M manganese (II) is possible from weakly acidic solutions. The use of lead dioxide as either a non-isotopic carrier or a chemical displacing agent makes possible high recoveries from more acidic solutions.

The photometric titration technique is used for the determination of weak bases using perchloric acid in acetic acid as titrant and acetic acid or acetonitrile as solvent. Differentiating titration of as many as four components in a single mixture is shown to be possible. Comparison with potentiometric titrations in the same media shows the photometric technique to be preferable in many instances where the bases to be differentiated are very similar in strength. The versatility of the photometric procedure in differentiating bases is greatly increased by the device of changing wavelength during titration of mixtures. (auth)

A program for determining the behavior of concrete shear keys under dynamic loading similar to that encountered in nuclear blasts was coupled with a study of the comparative behavior of shear keys under static loading. The testing procedure gave deflection recording for the shear keys, their strength in pure shear, under transverse compression and when dowelled, stresses and strains in the embedded dowels, and the mode of failure of each specimen. From an analysis of the data obtained and a study of the combined direct and transverse stresses involved, important qualitative conclusions were drawn from the common trends in the behavior of keys. The tests proved that plain concrete keys can withstand stresses in pure shear as high as 2000 p.s.i. or more, that imposing transverse compression on them raises the ratio of their shear strength to compressive strength by about 50% in dynamic loading though by only about 5% in static loading, and that the keys exhibit much higher shear strength when subjected to dynamic loads than when stressed by static loads. The test also indicated that the strength and quality of the gravel are probably major factors governing the strength of the keys.

The objectives of this research program are to determine bond strength under dynamic loading, to compare bond strengths under static and dynamic loading, and to test the adequacy of ACI Building Code bond requirements for structural elements subjected to blast loads. The tests have shown that local static bond strengths may be as high as 0.75 fc and that under dynamic loading this strength increases to fc. For all practical lengths of embedment of bars, steel failure is to be expected both under static and dynamic loading. Such bars loaded dynamically will carry a larger load than bards loaded statically, this increase in load carrying capacity of bars being sole due to the increase of steel strength under dynamic loading.

The cascade of displaced atoms in metals, induced by high energy radiation, has been investigated, with the assumption of a screened coulomb interaction between atoms. The problem was treated stochastically on an IBM 650 electronic computer for several different models. The comparison of our results with those for which a hard sphere interaction has been used shows only a slight decrease in the expected number of atomic displacements.

The cross sections for electric dipole photodisintegration of H/sup 3/ and He/sup 3/ at low energies are expressed in terms of the effective range parameters of the doublet n-d scattering matrix. Agreement with the experimental results is possible for either set of n-d scattering lengths.

An experiment is described in which high energy nuclear interactions in the range of energies 10(10)-10(12)ev were analyzed by means of a cloud chamber n a magnetic field. Measurements of ionization and momentum made possible the identification of electrons and mesons to about 20 Bev/c. Protons, K-mesons and hyperons could not be identified unambiguously among themselves, except in very limited regions of momentum. The primary particles were cosmic-ray nucleons and a possible fraction of Pions, the target nuclei were carbon and the velocities of the primaries were determined from balance of momentum in the center of mass system. A total of 41 events were analyzed, and the results compared to previous experimental work and the predictions of the theories of Heisenberg and Landau. The measurements made included the transverse momenta of the secondaries and their average energy in the CMS, the energy and angular distribution of the Pions and heavy particles (protons, K-mesons, hyperons) in the CMS, the inelasticity of the collision, the multiplicity of the showers, the percentages of strange particles and the positive excess of the secondaries.

Monthly letter report on the research on the development of a beta-ray particle size analyzer (BPSA).