An information storage and retrieval system (PIC) was developed, utilizing the IBM 7090 computer, for handling data pertaining to the effects of neutron irradiation on metals. The input includes a reference identification, an appropriate abstract or extract summarizing the article, code identification parameters analogous to those used by the ASM-SLA Literature Classification System, and special codes identifying relevant irradiation and testing parameters. The output contains the same data plus printing out the meaning of all special codes. Presently, the information storage consists of more than two hundred references representing several thousand lines of information. The system is both general and definitive, permitting the selection of a single piece of information or of many references dealing with a general field. It is possible to select material on the basis of one or more of the following factors: material, general or specific; type of literature; general or specific property such as mechanical tests or tensile tests; conditions of irradiation including type and level of flux, integrated flux, irradiation temperature, and reactor environment; test conditions such as temperature and environment; and general variables that might be controlling such as strain rate, specimen geometry, grain size, and fabrication history. It is felt that this …

The distribution of fuel elements in the EBWR core is described. Spike elements with boron steel strips were provided in the core for burnup allowance. A calibration of the control rod system with Zircaloy followers was made. Void coefficient measurements were made for two different H/sub 3/BO/sub 3/ concentrations. Power runs were made, and reactivity loss vs. power characteristic was obtained. Steam remaining in the core, or carryunder,'' was indicated. Some of the spikes were removed for increasing the power to 80 Mw. Calculations were made of the reactivity loss with coolant void and of the average void vs. reactor power. (D. L.C.)

A procedure is described for the activation determination of V in powdered milk using 3.77-min V/sup 52/. The quantity of V in the sample is obtained by comparing the V/sup 52/ radioactivity found in the test sample with the V/sup 52/ radioactivity in a V comparator sample that is treated in the same manner as the test sample. The procedure can also be used for the determination of V in a variety of materials. (P.C.H.)

Modern {beta}-ray spectrometers are based upon the concept, first introduced by Svartholm and Siegbahn in 1946, of focusing in both the radial and vertical directions. The theory of axially symmetric devices has been carefully studied by a large number of workers, culminating in the analysis, in 1956, of Lee-Whiting and Taylor. These last authors calculate aberrations through the sixth order and show that by appropriate choice of the magnetic field a spectrometer can be designed with a relatively large transmission and a high resolution. The acceptable transmission is remarkable because the second-order 'spherical' aberration in the median plane of the image cannot be made to vanish identically, and consequently the design is forced to a tall thin aperture (or a slightly less advantageous short wide aperture) which a priori would seem to imply a low transmission. It is the purpose of this communication to show that if the arbitrary restriction to axially symmetric fields is removed, then both the radial and the vertical contributions to the 'spherical' aberration can be made to vanish in second order. That azimuthally varying field (AVF) afford the freedom to accomplish this end may well be suspected in view of the technological revolution that the …

The longitudinal electromagnetic interaction of an intense coasting beam with itself, including the effect of a resistive vacuum tank, is investigated theoretically. It is shown that even in the range where the particle frequency is an increasing function of particle energy, the beam can be longitudinally unstable due to the resistivity of the vacuum tank walls. In the absence of frequency spread in the unperturbed beam the beam is shown to be always unstable against longitudinal bunching with a growth rate which depends upon (N/{sigma}){sup 1/2}, where N is the number of particles in the beam and {sigma} is the conductivity of the surface material. By means of the Vlasov equation, a criterion for stability of the beam is obtained; and shown in the limit of high-conductivity walls to involve the frequency spread in the unperturbed beam, the number of particles N, the beam energy, geometrical properties of the accelerator, but not the conductivity {sigma}. A numerical example is presented which indicates that certain observations of beam behavior in the MURA 40 MeV electron accelerator may be related to the phenomena investigated here.

The bremsstrahlung emitted by an electron scattered in a Coulomb field was first calculated by Bethe and Heitler. The total cross section for production of photons with wave number between k and k + dk by a nonrelativistic electron of kinetic energy {epsilon} is d{sigma}/dk dk = 16/3 Z{sup 2}r{sub 0}{sup 2} (e{sup 2}/hc) (mc{sup 2}/{epsilon})log ({radical} {epsilon}/hck + {radical} {epsilon}/hck -1) dk/k, where Ze is the charge of the (heavy) ion, and r{sub 0} is the classical electron radius. Bremsstrahlung in a plasma has been computed by a number of authors in the approximation of replacing the Coulomb field by a cut-off Coulomb or static Debye potential. It is the purpose of this communication to call attention to another important effect of the medium upon the rate of emission of bremsstrahlung. This may be described as a modification of the relation of the photon's energy to its wave number, due to the index of refraction of the medium. Equivalently, we note that one must include in the calculation of bremsstrahlung in a medium the photon-medium interactions which result in the 'clothing' of a 'bare' photon. The replacement of a particle by a quasiparticle has long been known to be …

The ground-state wave function and energy of a finite system of interacting fermions are expanded in terms of multiple-particle excitations on an uncorrelated zero-order state. The resulting set of coupled equations constitutes a systematic variational generalization of Hartree-Fock theory. Comparison is made with many-body perturbation theory and it is shown that to any order the theory incorporates an infinite number of perturbation theory terms. Solutions of the equations for ground-state atomic systems are discussed and related to previous work using many-body perturbation theory. It is shown that the sums of perturbation terms necessary for convergence are automatically included in the equations for two-particle excitations. Application of the equations to open-shell atoms is described.

Puromycin, an inhibitor of protein synthesis, appears to act as an inhibitor at additional sites during the induction of {beta}-galactosidase synthesis. No inhibition of the reactions proceeding during the first 20 seconds of induction was observed, but puromycin seems to prevent the accumulation of messenger RNA during the period between 20 seconds and the first appearance of enzyme activity after 3 minutes. When cells from a stationary culture are placed in fresh medium containing inducer for {beta}-galactosidase, growth, as represented by increase in turbidity and by total protein synthesis, starts within 30 seconds. By contrast, {beta}-galactosidase synthesis is greatly delayed compared with induction during exponential growth. Two other inducible enzymes show similar lags, but malic dehydrogenase, which requires no external inducer, shows no lag. The lags are not due to catabolite repression phenomena. They cannot be reduced by pretreatment of the culture with inducer, or by supplementing the fresh medium with amino acids or nucleotides. The lag is also demonstrated by an i{sup -} mutant constitutive for {beta}-galactosidase synthesis. An inhibitor of RNA synthesis, 6-azauracil, preferentially inhibits {beta}-galactosidase synthesis compared with growth in both inducible and constitutive strains. It is suggested that these observations, together with many reports in the …

Dye-macromolecule complexes provide good models for the study of the effects of coupling between chromophores. In addition to modifications of the visible and UV absorption spectra of the dyes at small interchromophore distances, very efficient energy transfer has been demonstrated at longer distances. The probability of nonradiative transition increases with the number of excitation transfers so that an array of oscillators close to one another becomes nonfluorescent. The insertion of a dye molecule, acting as a trap for the excitation energy, in the highly ordered system of chromophores constituted by the purine and pyrimidine bases of native DNA has given results supporting the intercalation model of Lerman and providing an experimental approach to the problem of the path length of energy migration in the DNA molecule. The average excitation path length seems to be of the order of only ten base pairs, a result which can explain the lack of fluorescence of the DNA.

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Over the past few years we have developed a system which allows several different liquid hydrogen and liquid deuterium targets to be placed in the electron beam of the Stanford Mark III accelerator and which can be operated from a remote position. The geometry of our scattering chamber requires that the motion (of the various targets into position) must be in the vertical direction, but that the overall height of the system be constant. These requirements are met by using an internal retractable bellows arrangement to raise and lower the target cells. As many as five cells can be used in conjunction with a single reservoir system.

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Thermodynamic considerations indicate that sodium should be favorable for the one-step reduction of UF/sub 6/ to uranium metal. A reaction vessel was developed for the continuous reduction of UF/sub 6/ to metal with batch collection of the products, and several experimental tests established the chemical feasibility of this direct and continuous reduction. Up to 93.5% of the uranium content of UF/sub 6/ continuously reduced by sodium in a reaction vessel was recovered as massive uranium metal in the form of a metal button of acceptable purity. A remaining problem is development of compatible materials of construction. (auth)

The labeling of newly-formed lymph cells with tritiated thymidine, lymphatic duct cannulation, and the peripheral destruction of lymphocytes by extracorporeal irradiation of the blood were used to estimate the mass of prestored lymphocytes and the relative degree of recirculation of 1ymphocytes from blood to lymph and back again. Topics discussed include the effects of extiacorporeal irradiation on the histologic picture of the lymphoreticular tissue, the influence of extracorporeal irradiation upon the thoracic duct output, and preliminary observations on labeling of lymphocytes by tritiated thymidine at the completion of extracorporeal irradiation. Data indicate that the mass of preformed small lymphocytes may be as large as 40 times that present in peripheral blood, that the blood feeds lymphocytes primarily into the lymph, and presents strong evidence for lymphocyte recycling. (C.H.)

A quantum correction of the statistical model of the atom was obtained by modifying March and Plaskett's region of integration in the (n/sub r/,l), or quantum-number, plane. Integrations over the plane lead, in the unmodified case, to the Thomas-Fermi density expression and energy equation. Integrations over the modified region are here shown to produce a modified Thomas-Fermi expression for the electron density, and a correction to the kinetic energy. The latter correction shows a similarity to the Weizsacker correction, but is smaller by a slowly changing factor of the order of 10. A modified Thomas-Fermi-Dirac equation was derived by the standard variational procedure. Numerical solutions of the equation were obtained, yielding atomic binding energies in much better agreement with experimental values than those of the unmodified theory. (auth)

A solenoid wound with high-field superconducting wire displays maximum currents and fields (H) that are less than the critical field of the wire itself in an equal field (H). Montgomery's and Chandraseknar and Hulm's models for these maximum properties indicate, respectively, a unique coil quenching characteristic for geometrically similar solenoids and one unique characteristic for all solenoids with identical wire type and turn distance. Experiments with Pb coils did not verify Montgomery's model and contradicted Chandrasekhar and Hulm's model. The experimental results, however, did support an analysis of the surface currents in an ideal superconducting infinitely long solenoid. (D.C.W.)

The application of an electronic data processing system to the unique combination of scientific and commercial data processing requirements of nuclear materials management is discussed. The organization and ilow of data from the plant through the data processing equipment to the final report are discussed. Included are topics concerned with the impact of conversion to electronic data processing on personnel, materials management costs, and on other plant organizations. Portions are devoted to programming systems and decision-making abilities of data processing equipment which make these systems readily adaptable to nuclear materials management. (auth)

Cr{sup++} in solution produces a paramagnetic shift in the NMR absorption of 0{sup17} in C1O{sub4}{sup-}, as well as the expected paramagnetic shift for 0{sup17} in H{sub2}O. As the concentration of C1O{sub4}{sup-} increases, the shift in the H{sub2}O{sup17} absorption is diminished, and eventually changes sign. The effects are ascribed to preferential replacement by C1O{sub4}{sup-} of water molecules from the axial positions in the first coordination sphere about Gr{sup++}.

Data are presented that show a marked species difference in the degree of damage and in the course of events seen in the bone marrow and peripheral blood after a given dose of radiation. The data taken together indicate strongly, but do not prove, that the picture seen results primarily from damage to the stem cell population. This damage to the stem cells is manifested later in the more mature differentiating cells of the marrow, and in the peripheral blood. The picture seen results both from death of stem cells, and also injury leading to reduced proliferative capacity, with later death of the injured stem cell and all of its progeny. Thus the picture seen is a result of both quantitative and qualitative changes resulting directly from the exposure of the stem cells, and species differences relative to sensitivity and time course of events appear to depend to a large degree on differential sensitivity of the bone marrow stem cell populations to death and injury. (auth)

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The solubility of silver oxide on silver metal is not the same as that of the bulk oxide. The differences in solubility were investigated by shaking silver powder in deaerated solutions of various concentrations of ammonia and in buffers of ammonia and ammonium nitrate at a constant temperature of 25 deg C. These solutions were shaken in an atmosphere of N/sub 2/ in a stoppered bottle and in the absence of light. The concentration of silver ion in these solutions was measured potentiometrically and by using tagged silver ions. The NH/sub 3/ concentrations were obtained by titration of aliquots of these solutions to the methyl red end point with HCl both before and after shaking. Although several days elapsed between these titrations, the concentration varied less than 1% in all cases. (auth)

A study was made of contact microradiographic techniques for the x-ray evaluation of tin specimens or selected small regions in large specimens. Extraneous absorbers such as air and the film holder were removed to permit the use of low-energy x rays, and high-resolution plates were used which permit magnifications up to 500x. Microradiographs are presented for graphite-coated uranium carbide particles, nickel screen, thin graphite section, and various fibrous materials. It is concluded that the contact microradiographic technique is a very useful tool. (D.L.C.)

An analysis of the effect of mutual friction between normal fluid and superfluid in the flow of liquid He II through narrow channels under large temperature gradients was recently given by Craig, Keller, and Hammel. This analysis is based on the Gorter-Mellink thermodynamical equations. An alternative treatment of the problem is presented in which the conservation of entropy is introduced naturally into the theory at an early stage. The role played by entropy production in the processes involved in the thermohydrodynamics is thereby considerably clarified and a simple relation is given for an estimate of the relative importance of normal fluid dissipation and mutual friction dissipation. (auth)