"Progress is reported on Phase II of a program for the development of a mixed fission product fueled thermoelectric generator. Materials studies are described in which bonded assemblies of bismuth telluride were life tested up to 3000 hours at 350 to 400 deg F hot junction temperature. Data were too inconsistent to define any satisfactory long-life bonding process. Further work is needed to eliminate the process variables. Insulation studies aimed at determining the thermal conductivity of various insulations with different fill gases under reduced pressures are described. Opacified aerogel powder appears to be very promising as an insulation medium for a diffuse heat source. A full- scale simulated test generator aimed at proving out the concept of a diffuse heat source for power generation is described. Progress on the construction of this electrically heated generator and its thermoelectric power converter is related.

Technical report. From Abstract : "The reactions of VCl2. VCl3, and VCl3-VBr3 mixtures with bromine vapor at 350 to 450°C led to vaporization of the halides and deposition of mixed halides of vanadium (III) at lower temperatures."

Technical report. From Abstract : "The thallium-rich region of the thallium-indium phase diagram was determined from atmospheric pressure to 5.5 kbars primary from electrical resistivity data obtained as a function of composition, temperature, and pressure."

From abstract: "Iron(III) can be separated from many elements by extraction from 6 to ͟8M hydrochloric acid. The extraction is carried out by passing the aqueous hydrochloric acid solution through a column packed with 2-octanone adsorbed onto a poly-fluorocarbon resin. Fluoride, phosphate, sulfate or citrate cause no interference. Traces if iron(III) can be separated quantitatively from large amounts of copper(II) or zinc(II); traces of titanium(IV) can be separated from large amounts of iron(III)."

From abstract: "A study has been made of the yields of gaseous products labeled with C11 from the C12(γ, n) reaction in liquid cyclohexane. The effects of variations in the radiation dose and in the concentration of dissolved iodine during irradiation on the yields of these products were studied in order to elucidate the reaction mechanisms. A reaction model was developed as a method of assessing the relative importance of radical and molecular processes. The data suggest (1) that the formation of C11 labeled CH4, C2H4 + C2H6, and C3H6 involves a hot radical process while (2) the formation of C2H2 is by a molecular reaction with cyclohexane."

From abstract: "The first order correction in αZ to the Bethe-Maximon pair production cross section is calculated for the case where the incident photon and one of the electrons has an energy much greater than mc2. Comparison of these calculations to the experimental data of Plimpton and Hammer shows an improvement ina greement between theory and experiment of approximately a factor of 1+(αZ4π/15) for low positron kinetic energies. However, for positron kinetic energies of the order of 1 Mev no improvement is obtained."

From abstract: "The electrical resistivity of NaxWO3, LixWO3, and KxWO3 has been measured at 300°K. The range of x-values was 0.25 < x < 0.9. All resistivities were characteristic of a metal and lie on a single curve. An extrapolation of the conductivity curve to zero conductivity indicated that the tungsten bronzes should be semiconductors for x < 0.25. The resistivities that have been measured for tungsten bronzes with x < 0.25 showed semiconducting behavior. The resistivity of LixWO3 exhibited an anomalous peak in the ρ vs Τ cuve. The Hall coefficient of Li0.37WO3 indicated one free electron per alkali atom as was previously found for NaxWO3. The Seebeck coefficient of NaxWO3 depended linearly on x[superscript]-2/3 as expected from free electron theory. The implications of these and some other data are discussed."

From abstract: "The electronic spectra arising from the excitations of pi-electrons in homo-nuclear conjugated bond systems are calculated for 37 aromatic hydrocarbons. The theoretical approach used takes into account overlap effects between different a atoms, correlation between different electrons, variations in internuclear distances, and the influence of non-conjugated neighbors, hydrogen and carbon. Four types of approximations are carried trough for the molecules in order to obtain an estimate of the inadequacies of the theory. From the calculated transition energies and oscillator strengths, theoretical spectra are synthesized and compared with observed spectra. In order to help the interpretation, a decomposition of the transition dipoles into atomic contributions is introduced. The spectra of alternant molecules are succesfully predicted, but the limits of the underlying assumptions appear to be exceeded in the applications to non-alternant systems. The calculations are markedly successful for the peri-condensed systems, which had presented an obstacle to previous treatments. It is found that the calculated spectra are fairly sensitive to small variations in interatomic distances. calculations with exact atomic positions, where available, give considerably better agreement with experimental spectra. The calculations lead to an understanding of the general spectral pattern found in all aromatic hydrocarbons. On this basis the …

Technical report. From Abstract : "The equilibria (1) VBr3(s) = VBr2(s) + 1/2Br2(g) and (2) 2VBr3(s) = VBr2(s) + VBr4(g) were studied over the range 644 to 805°K by transpiration in helium."

Technical report. From Abstract : "The vapor pressures of crystalline VCl2, VBr2, VCl3 and VBr3 have been measured by the Knudsen effusion method using pyrex and Vycor effusion cells. ... During the measurements on VCl3 and VBr3 dissociation and disproportionation of the samples occurred simultaneously with the simple vaporization. However, because the product of each of these processes was collected separately during an experiment, the vapor pressure due to sublimation was obtained without difficulty."

Abstract: This technical report describes the changes incurred in the PM-2A by the planned insertion of PM-2A Core II and the replacement of the startup and check sources. PM-2A Core II components were fabricated to specifications very nearly identical to those of PM-2A Core I. The essential difference in the cores is the boron loading which permits PM-2A Core II to meet a "one-stuck rod criteria" at beginning of life. This core has been subjected to a zero power experiment and loading procedures have been developed at the Alco Critical Facility. The nuclear and thermal and hydraulic characteristics are essentially identical to those of Core I and the replacement of the startup and check sources represent no increase in the potential for or magnitude of a hazardous situation.

Data processing program written to compute the neutron dose received by individuals exposed in a nuclear excursion.

Report issued by Oak Ridge National Laboratory that discusses progress and work performed by the Chemical Technology Division.