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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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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.

Using a polarized proton target, we have measured the polarization parameter P({theta}) in pion-proton scattering for both positive and negative pions. Because there seems to be a great deal of current interest in the analysis of pion-proton scattering we wish to present these experimental results at this time even though we have not yet completed their analysis. The measurement consisted of scattering pions from polarized target protons and observing the asymmetry in scattered intensity, I({theta}), as the target protons spin directions were reversed. The intensity for scattering from a target of polarization P{sub T} is I({theta}){sub pol.} = I({theta}){sub unpol.} (1 + P({theta})P{sub T}), where the parameter P({theta}) is the same as the recoil proton polarization in scattering pions from unpolarized protons under the assumption that parity is conserved in the process.

The average polarization of the {Sigma}{sup -} produced in the reaction {pi}{sup -} + p {yields} {Sigma}{sup -} + K{sup +} has been measured between center-of-mass angles 134{sup o} and 166{sup o} for an incident {pi}{sup -} momentum of 1145 MeV/c. A polarized proton target was used, and the {Sigma}{sup -} polarization was found by measuring the difference in the production-rate of K{sup +} mesons for protons polarized along the production-plane normal and against it. Spark chambers were used to record the {pi}{sup -} and K{sup +} trajectories, and the {pi}{sup -} momentum was obtained from a magnetic spectrometer while the K{sup +} momentum was obtained from a range telescope. Each event was kinematically reconstructed in a one constraint fit to help eliminate events produced from protons bound in heavy nuclei of the target. The {Sigma}{sup -} polarization was found to be -0.36 {+-} 0.46.

The purpose of this paper is twofold: to introduce the reader to the subject of instabilities exhibited by relativistic particle beams, and to summarize the present state of our knowledge concerning these phenomena. Most of the material in the first part of the paper is not new. It has been known to some specialists for a good many years; what is new is that the problems that can be solved are now of much more interest to the general community of accelerator physicists. Consequently, many accelerator physicists who have not paid much attention to these matters may now want to become informed; it is my hope that this paper will provide an introduction to the field. The second part of the article consists of two sections. The first summarizes the experimental information presently available, with emphasis upon the degree to which it confirms or disagrees with theory. Our current level of understanding is delineated: considering the generality and reliability of the theoretical analysis as well as the degree of experimental confirmation, the author expresses his opinion as to what can be considered relatively well established. The final section contains a discussion of subjects needing further investigation and, consequently, supplements the …

Charge transfer associations are a well-established phenomena and a rather extensively investigated one also. Since the acceptor component of such complexes normally does not exist as a liquid under standard conditions, they wish to report on two organic liquids which function as acceptor components with suitable complimentary molecules. As indicated in Figure 1 (the presence of an extended shoulder in the spectra of the mixture), pentafluorobenzonitrile (PFBN) complexes with N,N,N{prime},N{prime}-tetramethyl-p-phenylenediamine (TMPD), with N,N-dimethylaniline (DMA), and with phenothiazine in cyclohexane. In addition, crystalline complexes of TMPN-PFBN and DMA-PFBN are obtained when the pure materials are mixed. These two organic bases also form solid complexes with hexafluorobenzene (HFB) when the materials are mixed in the pure state in a ratio of 1:1. However, new absorption bands are not detected in the spectra (in cyclohexane solutions) of mixtures of TMPD or DMA with HFB. When HFB is used as a solvent for TMPD or DMA, the solutions are visibly yellow. However, with time a reaction occurs as evident by the formation of a black precipitate. The solid complex formed between TMPD-PFBN, which is orange, was analyzed by a combination extraction and spectroscopic method and by vapor phase chromatography and found to contain a …

A progress report is presented on the activities at LRL in connection with electron-ring accelerators. A two-stage compressor unit (employing only low-intensity beams) has been built, and operated with a 4-MeV 100-mA linac as an injector. Electron rings have been formed and compressed from 20 cm radius to 7 cm radius. A three-stage compression unit has been constructed and is now under test with the high intensity (200 A) 3.3-MeV beam of the Astron injector. The apparatus is described. Design work on a magnetic expansion unit is reported.

Economic and operational ground rules and their effects on fuel management are summarized, and examples showing the approach to typical fuel management problems are presented. The problems associated with in-core fuel management are also discussed, and the merits of various fuel cycling methods are evaluated. (D.C.W.)

It was thought that if a multi-detector device could be developed, the scanning time would be greatly shortened, with such consequent advantages as being able to work with lower dose of radiation, to obtain serial determinations, and to work with shorter-lived isotopes.

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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)

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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)

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)

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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.)

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When the construction of the confinement facilities for Hanford production reactors is completed, the potential for contaminating the environment with accidentally released fission products will be greatly reduced. This was demonstrated already when rupture debris burned in the rear face area of one of the reactors in which the fog spray was installed and ready for service. The fog spray effectively prevented the spread of contamination to the ventilation equipment downstream of the rear face enclosure. Also, the commercially- available absolute filters and charcoal beds will significantly decontaminate the exhaust air, stream of all fission products except the noble gases. Laboratory studies indicate that the filter system should remove at least 50 percent of all fission product halogen vapors and over 90 percent of the particulate matter released from a nuclear incident. In addition, the charcoal beds should provide an additional 90 to 95 percent decontamination of the halogens that manage to pass through the filter. It is not expected that any of the noble gases released will be removed by this system. Laboratory studies, in general, substantiate previous estimates on the release of fission products from overheated uranium fuels. The theoretical estimates are quite accurate for the volatile and …

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