The heat capacity of terbium metal was measured between 0.25 and 1.0 deg K. The high temperature data can be expressed as C = 28R x 10/sup -3/T/sup 2/ cal/ mole-deg. The data are compared with a Schottky formula for the heat capacity, assuming equal spacing between the nuclear hyperfine levels with an over-all spacing of beta = 0.45/ deg K, correspondlng to the high temperature expression above. The agreement is within experimental error except at the very lowest temperatures obtained. The effective field at the nucleus of the terbium atom can be calculated and is found to be H/sub eff/= 4 x 10/sup 6/ gauss. (auth)

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Empirical study of cubic and quartic vibrational force constants for diatomic molecules shows them to be approximately exponential functions of internuclear distance. A family of curves is obtained, determined by the location of the bonded atoms in rows of the periodic table. Displacements between successive curves correspond closely to those in Badger's rule for quadratic force constants (for which the parameters are redetermined to accord with all data now available). Constants for excited electronic and ionic states appear on practically the same curves as those for the ground states. Predictions based on the diatomic correlations agree with the available cubic constants for bond stretching in polyatomic molecules, regardless of the type of bonding involved. Implications of these regularities are discussed. (auth)

No Abstract. There is a duplicate copy.

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Techniques are described for obtaining x ray diffraction information on active metals at high temperatures. One method is used to 1000 deg C with rare earths; the other method is used to 2200 deg C with tungsten, and to 1400 deg C with some f the higher melting rare earths. The latter approach permits simultaneous measurement of resistance of the specimens vs temperature and the diffraction pattern, which facilitates the characterizing of the high temperature forms of the metals. (auth)

A back-reflection Laue camera with three rotation axes and three orthogonal translation axes is described. This camera allows the alignment of large single crystals with a precision of plus or minus 0.25 deg . The degree of single crystallinity of a specimen may be examined. In addition it is possible to accurately mark a crystal for subsequent utilization. (auth)

Recently a T = 1 resonance in the {Lambda}{pi} system called Y*{sub 1} has been observed with a mass of 1385 Mev. Two types of resonances have been predicted that might relate this observation to other elementary-particle interactions: (1) P 3/2 resonances in the {Lambda}{pi} and {Sigma}{pi} systems predicted by global symmetry corresponding to the (3/2, 3/2) resonance of the {pi}N system; (2) a spin-1/2 Y-{pi} resonance resulting from a bound state in the KN system. The position and width of the observed Y*{sub 1} resonance agree with both theories, but since the spin and parity have not yet been determined, it is impossible at present to distinguish between the two theoretical interpretations.

Two types of electron polarization operators are surveyed. A three- vector operator is described that is appropriate for calculations involving plane- wave states. A four-vector operator is described that can be used for taking account of external electromagnetic fields. (T.F.H.)

The beta spectra of In/sup 114/, P/sup 32/, and Y/sup 90/ were stud ied closely in an intermediate-image beta-ray spectrometer and compared to theoretical predictions in terms of a linear shape factor of the form (1 + aW). The values obtained for a were s for P/sup 32/, and (-0.0047 plus or minus 0.0008)/mc/sup 2/ for Y/sup 90/, all for electron kinetic energies from about 200 kev up to near the maximum beta energies. Tests were made to give indications for spectrometer fidelity. Because of the linearity of the shape-factor plots and the similarity in energy range, the comparative results from In/sup 114/, P/ sup 32/, and Y/sup 90/ are tak en as a definite indication that for at least two of these activities the shape factors have nonzero slopes, irrespective of questions of instrumental fidelity. (auth)

The electrical resistivities of polycrystalline samples of La, Pr, Nd, and Sm are reported in the temperature range 1.3 to 300 deg K. La exhibits a superconducting transition at 5.8 deg K. The curve for Pr has slope changes at 61 and 95 deg K. The Nd curve shows small jumps at 5 and 20 deg K. Sm shows slope changes at 14 and 106 deg K. (auth)

Safety precautions utilized for control and cominement of fissionable and radioactive materials in the various aqueous reprocessing operations performed at the Idaho Chemical Processing Plant are presented. Three primary nuclear safety controls, geometrical, mass limitation, and concentration control, are used. Operations are penformed according to standard operating procedures which are set up to prevent circumvention of the primary nuclear safety controls. The various processing operations with their particular safety features are discussed. The operations include receipt, handling, and storage of irradiated fuel elements, dissolution of the fuel elements in various reagents, separation of the unburned fissionable material from fission products and fuel element structural materials by solvent extraction, salvage or recycle operations of off- specifications product or waste solutions that exceed the dispossble fuel concentrationalimits, product packaging, storage and shipment, fission product recovery, and waste collection, handling and disposal. The originai plant design and later additions and modifications included built-in geometrical control wherever practical with allowances for possible neutron interaction between vessels. The standard operating procedures specificaily state mass limits and concentration controls required for certain operations which involve appreciable quantities of uranium. Administrative control insures compliance with the standard operating procedures. (auth)

The interaction Hamiltonian for the Coulomb exchange effect between conduction electrons and magnetic-shell electrons in rare-earth metals was derived from first principles. The approximations under which the interaction can be represented by the product of electron and ion spin vectors are exhibited. (auth)