bluuebunny/crossref_metadata_2025 huggingface dataset:
Octupole deformations in the 2s–1d shell
Authors: Castel B. , Svenne J. P.
Published: April 2011

The dependence of the nuclear energy on the deformation parameters of order two and three is investigated for some s–d shell nuclei. A Hartree–Fock technique is used to calculate the stiffness parameters for quadrupole and octupole deformations. The nuclei most soft under quadrupole and octupole deformations are seen to be 30Si and 38Ar, respectively. The reduced E3 transition rates are calculated and are compared with available experimental results.
The efficient use of stabilizing materials in superconducting solenoids
Authors: Stevenson Richard
Published: April 2011

The problem of stability of superconducting solenoids is considered from a thermal point of view. The transient heat conduction equation for a superconducting tape clad with normal material and operated in a current sharing mode is studied, and a solution for the temperature distribution is obtained. The composite conductor is considered stable if its final temperature in the current sharing mode corresponds to the critical temperature for the initial current density in the superconductor. Using this criterion, the operating point of the superconductor and its stabilizing cladding thickness can be chosen to give a maximum average current density in the composite conductor at any field. Calculations are given for Nb3Sn tape clad with OFHC copper and with high purity aluminium.
Removal of meteorological effects from meson-telescope data
Authors: Briggs R. M. , Hicks R. B. , Standil S.
Published: April 2011

Hourly data from a meson mega-telescope have been correlated with the local barometric pressure, the ground-level temperature, and with intensity variations as observed by a distant neutron monitor. Two techniques are considered, viz. a vector least-squares analysis and an hourly regression analysis, the latter being suggested as a practical method whereby stations without radiosonde information may correct their hourly meson data for changing meteorological conditions.
Transient radiation in a plane stratified dispersive medium. II. Exponential profile, plasma slab, and plasma gap
Authors: Ott Edward , Shmoys Jerry
Published: April 2011

In a previous paper by the authors, a similarity principle was derived for a class of transient diffraction problems in cold, lossless, isotropic, plane stratified plasmas. In this paper, the similarity principle will be utilized to obtain exact closed-form solutions to three specific problems; the problems of an impulsive point magnetic dipole (the current density is a delta function in space and time) in the presence of (1) a continuously varying plane stratified plasma with an exponential electron density profile, (2) a grounded plasma slab, and (3) a grounded plasma gap. In the case of the exponential electron density profile, the solution to the problem suggests a new type of approximation to cases where the profile is slowly varying but otherwise arbitrary. In the case of the slab and gap problems an interpretation will be given in terms of multiply-reflected rays within the slab. The gap problem is particularly interesting because, if the impulsive time dependence of the source were replaced by a harmonic time dependence, this problem would be distinguished by the presence of a surface wave. Thus an examination of the gap problem serves to illustrate the role played by the surface wave in the transient case.
Measurement of radio-meteor ionization profiles
Authors: Jones J.
Published: April 2011

The theory of a method for the determination of electron line density profiles of underdense radio meteors is developed, and the effects of cosmic noise, winds in the meteor region, and ambipolar diffusion on the measured profiles are estimated. The design of a device for the automatic determination of radiometeor ionization profiles is described, together with some results obtained using it in conjunction with the Ottawa–London (Ontario) backscatter system.
Temperature dependence of the crystal-field splittings and hyperfine structure in Eu2+:CaWO4 and evidence for nuclear quadrupole interactions
Authors: Harvey J. S. M. , Kiefte H.
Published: April 2011

The crystal-field splittings and hyperfine-structure constants of Eu2+ in CaWO4 have been accurately measured at 4.2 °K and at 78 °K using the method of electron paramagnetic resonance. These measurements were intended to provide liquid-helium temperature parameters for ENDOR experiments presently in progress but showed significant differences from the earlier measurements of Bronstein and Volterra. Because of these differences and the considerable current interest in the values of these parameters for S-state ions, z-axis measurements were extended to cover the temperature range from 1.8 °K to room temperature.A very good fit to the measured line positions has been obtained by carrying out an exact diagonalization of the spin Hamiltonian within the 8S7/2 manifold. The parameters fitted are [Formula: see text], [Formula: see text], b20, b40, b44, b60, b44, A, and B. Residual discrepancies, of the order of a tenth of a line width, are shown to be consistent with the presence of a purely ionic quadrupole interaction and an interaction between the nuclear quadrupole moment and the crystalline electric field. The temperature variation of the dipolar hyperfine-coupling constant is shown to be consistent with the theory of Šimánek and Orbach as extended to rare earth ions in cubic lattices by Menne, Ames, and Lee if a Θ of 150 °K is assumed. Within the restrictions imposed by the lack of thermodynamic data and the assumption of a point-charge lattice, it is shown that the temperature dependence of the fourth- and sixth-order crystal-field parameters is consistent with the predominance of a splitting mechanism at least quadratic and more probably of fourth power in the crystalline potential. The second-order axial parameter is found to have a temperature dependence which can not be explained in terms of a single mechanism.
A stabilized rocket-released magnetometer
Authors: Kavadas A. , Koehler J. A.
Published: April 2011

A rocket-borne magnetometer probe capable of determining all parameters of the earth's field is described. The probe which is attitude stabilized may be released from the parent vehicle to sample the earth's field away from the disturbing effects of the rocket.The basic instrument consists of a spinning coil. It is shown that this instrument can detect very small changes in both the magnitude and direction of the earth's field. Its basic features and limitations are discussed.
A rocket-released magnetometer probe for upper atmospheric measurements
Authors: Koehler J. A. , Kavadas A.
Published: April 2011

The construction of a new type of rocket-borne magnetometer as proposed by Kavadas and Koehler is described. The preliminary results of the first flight of the prototype instruments are presented.It is shown that the instrument is quite sensitive and can measure changes in the environmental magnetic field of a few γ's. During the first flight, a localized current in the ionosphere was detected at an altitude of 110 km.
Note on the decay of 43K
Authors: Taylor H. W. , King J. D. , Ing H. , Cox R. J.
Published: April 2011

The gamma rays emitted by radioactive 43K have been observed with a Ge(Li) spectrometer. Gamma rays with energies (intensities) of 219.2 ± 0.7(8 ± 3), 373.0 ± 0.5(101 ± 5), 397.8 ± 1.0 (11 ± 3), 592.5 ± 1.2 (10 ± 2), and 617.2 ± 0.5 (81 ± 5) keV have been identified. No direct evidence was found for gamma rays with energies of 388 and 1005 keV. A level scheme for 43Ca was constructed with levels at 373.0 ± 0.5, 592.4 ± 0.8, and 990.2 ± 0.7 keV.
Comments on scattering from a metallic cylinder coated with an inhomogeneous dielectric sheath
Authors: Parkinson R. G. , Kharadly M. M. Z.
Published: April 2011

Values of computed backscattering cross section, significantly different from those previously published, are reported.
The 23Na(α,γ)27Al reaction. A survey of the reaction and some properties of the 27Al nucleus
Authors: Röpke H. , Anyas-Weiss N.
Published: April 2011

The 23Na(α,γ) reaction has been studied in the region Eα = 2–3 MeV. The γ-ray spectra from a total of 16 resonances have been surveyed using a 40 cm3 Ge(Li) detector. Excitation energies, γ-ray decay modes, branching ratios, and γ-ray yields of these resonances are given. Below Eα = 2.7 MeV, all resonances have [Formula: see text] and the α-particle capture proceeds with [Formula: see text]. The resonances at Eα = 2.696 and 2.797 MeV have strong branches to the Jπ = 11/2+ state in 27Al at 4.509 MeV excitation energy. A measurement of γ-ray angular distributions at these resonances yields Jπ(2.969 res.) = 9/2+, 11/2 and Jπ(2.797 res.) = 9/2+ for the resonances, and Jπ(5.671) = 9/2+, 7/2 and Jπ(4.580) = 9/2+, 7/2 for bound states in 27Al. Investigation of this latter level at the Ep = 2.114 MeV resonance in the 26Mg(p,γ)27Al reaction restricts the spin to 7/2. New excited states in 27Al were found at Ex = 5.504, 5.671, and 7.815 MeV. A state at Ex = 5.499 MeV was confirmed.
Nuclear magnetic resonance in paramagnetic Mn2P2O7
Authors: Atkinson R. J. , Stager C. V.
Published: April 2011

The nuclear magnetic resonance of 31P has been observed in single crystals of Mn2P2O7 at room temperature. The paramagnetic shift of the 31P resonance from γH0 has been determined for rotations of the magnetic field in three principal planes. The isotropic component of the shift indicates the presence of 0.647 ± 0.01% of a single unpaired s electron on the phosphorus ion.
On the theory of electrostriction in finite ionic crystals: non-piezoelectric case
Authors: Grindlay J. , Wong H. C.
Published: April 2011

Equations are obtained for determining the temperature independent electrostrictive coefficients of a finite non-piezoelectric ionic crystal composed of point charges on an arbitrary basis. The derivation is based on the assumption that the relaxation of the interionic spacing at the surface of the crystal extends only over a few layers of ions. The special case of a diatomic crystal with NaCl structure and nonpolarizable ions is discussed and the results used to calculate the electrostrictive coefficients of NaCl, KCl, and KBr.
Investigation of the rotational structures in the ν1 and 2ν1 bands of monobromoacetylene
Authors: Huhanantti Mikko , Anttila Rauno
Published: April 2011

The rotational structures of the ν1 and 2ν1 bands of monobromoacetylene have been investigated. The values B″ = 0.13320 ± 0.00010 cm−1 and D = (1.7 ± 1) × 10−8 cm−1 were obtained. The centrifugal distortion constant was also computed theoretically and the result was 2.4 × 10−8 cm−1. From the obtained B″ value and from the C—H and C≡C bond lengths of structurally related molecules the C—Br distance was found to be 1.791 Å.
High-temperature critical properties of the Ising model on a triple of related lattices
Authors: Leu J. A. , Betts D. D. , Elliott C. J.
Published: April 2011

Three regular three-dimensional lattices of coordination numbers, q = 3, 4, and 6 are introduced. Exact relations are derived among the specific-heat singularity amplitudes and among the susceptibility singularity amplitudes. Exact high-temperature series expansions for the partition function and the susceptibility are derived for the q = 3 and q = 6 lattices. Precise values of the critical temperature, susceptibility amplitude, critical energy, and critical entropy are obtained for all three lattices. The variation of Ising critical parameters with coordination number is discussed.
On banding in the aluminium–silicon eutectic alloy
Authors: Kerr H. W.
Published: April 2011

Some of the statements and interpretations of the recent paper by Falquero et al. are discussed. It is suggested that the banding which they observed is due to convection, rather than a periodic buildup of impurities.
Calculation of cross sections for the depolarization of 2P states in alkali atoms
Authors: Gordeyev E. P. , Nikitin E. E. , Ovchinnikova M. Ya.
Published: April 2011

Optical pumping experiments have yielded very large disorientation cross sections (40–100 Å2) for collisions between oriented 2P1/2 atoms of potassium, rubidium, cesium and thalium, and helium, neon, argon, krypton, and xenon atoms in their ground states, in contrast to the extraordinarily small cross section (< 10−5 Å2) for the depolarization of 2S1/2 atoms, as found by Gallagher and by Anderson and Ramsey. Franz, Leutert, and Shuey pointed out that, within the adiabatic model, the transition ψ(j = 1/2, m = 1/2) → ψ(j = 1/2, m = −1/2) is strongly forbidden in conformity with Kramer's theorem according to which it is impossible to split the two components ψ(j = 1/2, m = ± 1/2) in an electric field. In the present investigation it has been shown that the inclusion of an angular nonadiabatic operator (i.e. the operator responsible for Coriolis mixing of adiabatic electronic molecular states) makes possible such transitions. Calculations are presented of cross sections for the resulting depolarization induced in collisions between potassium, rubidium, and cesium, and inert gas atoms.
Evidence against the 1580-keV level in 134Ba proposed by T. S. Nagpal
Authors: Singh B. , Kukoč A. H. , Taylor H. W.
Published: April 2011

The gamma-ray spectrum of 134Cs has been studied with a high-resolution Ge(Li) detector in order to obtain evidence of a 1580-keV transition reported elsewhere. No evidence for a 1580-keV level was observed in the spectrum.
Electron spin resonance of Mn2+ impurities in morinite
Authors: Manoogian A. , Hsu Y.
Published: April 2011

The electron spin resonance of Mn2+ impurity ions in natural crystals of morinite, Ca4Na2Al4(F, OH)10(PO4)4∙3H2O, was studied in the 9.4 GHz microwave frequency range and at room temperature. A single magnetic complex was found and the resonance lines were characterized by strong splittings due to superhyperfine interactions with ligand nuclei. The resonance lines were fitted to a spin Hamiltonian of orthorhombic symmetry and the following parameters were determined: gz = 2.0014 ± 0.0005, gy = 2.0017 ± 0.0010, b2°= 166.8 ± 1.5, b22 = 69.1 ± 1.5, b40 = −0.17 ± 0.10, A = 98.2 ± 1.0, and B = C = 99.7 ± 1.5. The values of bnm, A, B, and C are in gauss, and the signs are relative. By heat-treating powdered samples of morinite to a temperature greater than 400 °C, it was shown that the morinite changed to apatite, 2[Ca5(PO4)3(F, OH)].
A conjecture regarding quantized gravitational theory and elementary particles
Authors: Harris Paul
Published: April 2011

The gravitational action integral is evaluated for the case of a spherical potential surrounding a spherical mass shell particle. The gravitational action integral is quantized in the Bohr approximation, and a relation is found which connects the particle mass and radius to the Hubble constant.
Lambda-temperature depression in rotating liquid helium
Authors: Brouwer W. , Pathria R. K.
Published: April 2011

The depression of the transition temperature has been calculated on the basis of the increased inertial density of excitations in a rotating medium. The result obtained is more general than, and under special conditions reduces to, the previous results derived by Andronikashvili, Mamaladze, and co-workers.
Observation of a localized magnetic excitation in Co-doped KMnF3
Authors: Svensson E. C. , Buyers W. J. L. , Holden T. M. , Cowley R. A. , Stevenson R. W.H.
Published: April 2011

A magnetic local mode associated with the cobalt impurities in a single-crystal specimen of the antiferromagnet KMn0.8Co0.2F3 has been observed by means of neutron inelastic scattering. At 20 °K, its frequency is 6.55 ± 0.15 THz. If it is assumed that (JCo–Mn)2 = JCo–Co × JMn–Mn, and allowance is made for the exchange mixing of the levels of the cobalt ion, then a calculation of the frequency of the local mode using molecular-field theory gives 6.8 THz, in satisfactory agreement with experiment. From the variation of the intensity of the local mode with wave-vector transfer, the probability that the localized excitation is on one of the nearest neighbors to a cobalt ion is estimated to be 0.08 ± 0.03. Measurements of the acoustic spin waves propagating along the [00ζ], [ζζ0], and [ζζζ] directions at 20 °K have also been carried out. Their frequencies are essentially the same as those of pure KMnF3 except near the center of the magnetic Brillouin zone where they are slightly lower. The maximum frequency of the acoustic spin waves is 2.30 ± 0.04 THz.
Charged spheres in general relativity
Authors: Faulkes M. C.
Published: April 2011

The Einstein–Maxwell equations for a spherically symmetric distribution of charged matter are studied. A general equation is derived for the rate of change of the "total energy" of the sphere in terms of the 4–4 component of the electromagnetic and matter tensors. It is shown that, subject to certain conditions, the spheres of charged matter can oscillate, and further that the static configuration is uniquely given by the relation m2 = 4πe2α, where [Formula: see text]. Finally, it is demonstrated that the equilibrium configuration is unstable to small radial perturbations.
Higher order elastic constants of some face-centered cubic metals
Authors: Sharma Y. P. , Mathur S. S.
Published: April 2011

The second, third, and fourth order elastic constants have been calculated using the Morse potential function for seven face-centered cubic metals taking into consideration the truncation up to 134 nearest atomic interactions. The calculated values have been compared with the experimental data and have been used for calculating the pressure derivatives of the second order elastic constants. The agreement between the calculated values and the experimental results is quite good.
Phenomenological analysis of the reaction p + p → π+ + d
Authors: Brown D. J.
Published: April 2011

A simple Regge pole model is shown not to be adequate to explain the data in the region of incident-proton energy > 7 GeV. It is shown that the data can be explained if the process is dominated by a Regge cut.
I. Cosmic-ray latitude survey in North America in summer, 1965
Authors: Carmichael H. , Bercovitch M. , Steljes J. F. , Magidin M.
Published: April 2011

A 3-NM-64 neutron monitor and a 2-MT-64 muon monitor were operated overland at 44 sites near sea level and on mountains in Canada, the USA, and Mexico in April, May, and June, 1965, when the intensity of cosmic radiation attained its 11-year maximum. The equipment is briefly described and the original results of the measurements are listed. Some necessary corrections for instrumental effects are discussed. The corrections made to eliminate the secular variations of the cosmic radiation and the dependence upon temperature structure of the atmosphere are given in detail. This paper is the first of a set of five dealing with latitude surveys made in 1965 and 1966. Reduction of the observations to a common pressure level is carried out in the final paper of the set.
IV. Geographically smoothed geomagnetic cutoffs
Authors: Carmichael H. , Shea M. A. , Smart D. F. , McCall John R.
Published: April 2011

Detailed calculations of effective vertical-trajectory cutoff rigidities have failed to eliminate a discontinuity in the neutron-monitor latitude variation in the vicinity of Mexico City noted after the 1965 survey described in paper I of this set of five papers. Since a similar discontinuity appears when the vertical cutoffs are plotted against geographical latitude, the irregularity seems to be a function of the vertical rigidity cutoffs. Extensive calculations of cutoffs at, intervals of one degree of latitude along meridians 260 °E and 285° E have delineated the systematic nature of the irregularity. A set of cutoff values, which orders the observations satisfactorily for the analysis in the present papers, was obtained by smoothing a 5° latitude by 15° longitude grid of calculated values within a sector of the northern hemisphere bounded by meridians 195 °E and 285 °E.
V. Analysis of IQSY cosmic-ray survey measurements
Authors: Carmichael H. , Bercovitch M.
Published: April 2011

In this, the last of a set of five papers reporting latitude surveys carried out in 1965 and 1966 at the time of and soon after the IQSY cosmic-ray maximum, the observations are reduced to a common atmospheric depth and at the same time the attenuation coefficients in the atmosphere for both the neutron monitor and the muon monitor are determined as functions of altitude and latitude. The latitude variation of the neutron monitor at sea level is compared with observations reported for the previous cosmic-ray maximum in 1954–55 and found to be similar. The altitude variation of the neutron-monitor attenuation coefficient is discussed in detail with reference to the maximum near 600 mm Hg currently attributed to neutrons produced in the monitor by stopping muons. It is shown that the stopping-muon effect is insufficient to account for the maximum. It is shown, using the Gross transformation, that a geometrical effect associated with the omnidirectional nature of the incident cosmic radiation may be the main factor producing the maximum. A specific absorption coefficient representing the differential effect in the neutron monitor of vertically-incident primaries of given magnetic rigidity is deduced. Good agreement is obtained with the observed attenuation in the atmosphere of solar protons of mean energy 2 GV and also with the reported results of a Monte Carlo calculation of the attenuation of the nucleonic cascade in air.
Potassium hexachloropalladate and potassium hexachloroplatinate: a comparative study using nuclear quadrupole resonance
Authors: Armstrong Robin L. , Cooke Douglas F.
Published: April 2011

Measurements of the temperature dependence of the nuclear quadrupole resonance frequency νQ and spin–lattice relaxation time T1 of the 35Cl nuclei in powdered samples of K2PdCl6 are reported. The data are qualitatively similar to earlier results for K2PtCl6 and are analyzed in the same manner. The temperature dependence of both νQ and T1 are dominated by the F1g rotary lattice mode of frequency ~ 41 cm−1. The data for K2PdCl6 and K2PtCl6 are compared and the parameters characterizing the NQR behavior tabulated. It is suggested that the quantitative explanation of the rather small differences observed might provide a challenging problem for a molecular orbital theorist.
Transient analysis for stimulated thermal scattering
Authors: Enns R. H. , Batra I. P.
Published: April 2011

In previous treatments, the nonlinear gain per unit length for stimulated thermal scattering has been calculated using a steady-state approach without examining the conditions under which such an approach is valid. Here we present a transient analysis and calculate the time which must elapse before the steady-state theory becomes applicable. We show that in both stimulated thermal Rayleigh and stimulated thermal Brillouin scattering it is the so-called Rayleigh lifetime τR which determines the onset of steady state.
Generation and detection of acoustic waves in metals by means of electromagnetic radiation
Authors: Turner R. , Lyall K. R. , Cochran J. F.
Published: April 2011

A macroscopic theory is presented to explain the electromagnetic generation of acoustic waves in a metal in the presence of a steady magnetic field, and to account for the effect of these acoustic waves on the surface impedance. The theory is valid for the limiting case where the skin depth is much smaller than the wavelength of sound. In particular, the size and shape of the surface impedance singularities at frequencies corresponding to the formation of standing acoustic waves in a metal plate are calculated. Absolute measurements of the surface resistance and reactance of gallium single crystals are reported which are in quantitative agreement with the predictions of the theory.
A remote data-recording station
Authors: Staniforth A.
Published: April 2011

Wandering of the point which is geomagnetically conjugate to Byrd, Antarctica, can apparently be detected by making simultaneous auroral observations at the Byrd station and at sites in the vicinity of Great Whale River. Unattended stations which automatically measure and record auroral intensities for a period of two months are needed to continue the conjugate-point studies. A feasibility study of unattended stations for this kind of observation was made, and a station which measures auroral intensities and records the data in a computer-compatible form was designed and tested in July and August, 1968.
Double exchange and electron hopping in magnetite
Authors: Rosencwaig A.
Published: April 2011

A Zener double-exchange model is formulated for magnetite and is used to describe the electron-hopping process. The main consequence of this model is that the electrons participating in the hopping process in any imperfect or nonstoichiometric (i.e. real) sample of magnetite can be regarded as being essentially localized to hopping within particular (Fe2+–Fe3+) octahedral cation pairs, and not as being in either some form of 3d conduction band or as participating in a nonlocalized electron-transfer process. Well-known results on the electrical conductivity, and new results with the Mossbauer effect in magnetite are then explained in terms of this pair-localized electron-hopping model.
Angular correlations in 23Na(p,γ)24Mg
Authors: Baxter A. M. , Mabey C. , Gillespie B. W. J. , Kuehner J. A.
Published: April 2011

The decays of two resonances in 23Na(p,γ)24Mg have been studied by γ–γ angular correlation methods. These resonances occur at proton energies of 1020 and 1318 keV and correspond respectively to levels in 24Mg at 12.671 and 12.957 MeV. In the latter case, the analysis of the data leads to an assignment of J = 1 to the level at 12.957 MeV. The angular correlation measurements confirm a previous assignment of J = 2 to the 12.671 MeV level and the information on magnetic substate populations obtained from the angular correlation analysis, together with a measurement of the angular distribution of the 12.671 to 8.86 MeV transition, yield an assignment of 2− to the 24Mg level at 8.86 MeV.
Temperature noise in a thermally homogeneous conductor
Authors: Kshatriya Amarnath , Burgess Ronald E.
Published: April 2011

A thermally homogeneous conductor is characterized by complete correlation in temperature at all points on it. A theory for temperature noise in such a conductor is developed. A relation for spectral density of heat current fluctuations between two black bodies in radiative contact is derived.Erroneous analytical expressions used in the past for evaluating bolometer performance by a number of authors are reconsidered in the light of the theories developed in this paper.
Exact solution of a static charged sphere in general relativity
Authors: Wilson S. J.
Published: April 2011

An exact solution of the field equations of general relativity is obtained for a static, spherically symmetric distribution of charge and mass which can be matched with the Reissner–Nordström metric at the boundary. The self-energy contributions to the total gravitational mass are computed retaining only the first order terms in the gravitational constant.
Direct collection of some metal ions in an electromagnetic isotope separator and related surface effects
Authors: Fontell A. , Arminen E.
Published: April 2011

The direct collection of Fe, Co, Ni, Cu, Zn, and Sn ions has been investigated in the energy range from about 10 eV to 110 keV in an electromagnetic isotope separator. At low energies the ions build up a layer on the surface of the graphite block used as a backing, while at high energies only a certain saturation value can be collected. For these ions the highest energies at which the building-up of a layer was observed were 1.5 keV, 1.0 keV, 0.8 keV, 0.3 keV, 0.3 keV, and 0.45 keV, respectively. In the building-up region the efficiency of the collection process and the sticking probability of ions as a function of energy have been measured. From these the self-sputtering ratios have been calculated. In the saturation region the amounts of material collected have been measured and the ranges of ions in graphite backings saturated with metal atoms have been calculated theoretically. This calculation gives an estimate of the metal atom concentrations in the graphite, which in turn determines the sputtering ratio of carbon.
The uncertainty principle and the statistical interpretation of quantum mechanics
Authors: Ballentine L. E.
Published: April 2011

It is reemphasized that the uncertainty principle applies to state preparation rather than to measurement. An objection by Robinson to the statistical interpretation of quantum mechanics is shown to be unjustified.
The dissociation energy of gaseous diatomic sulfur
Authors: Ricks J. M. , Barrow R. F.
Published: April 2011

Three limiting curves of predissociation for the F1, F2, and F3 components of the state B3Zu− of S2 have been obtained following a detailed rotational analysis of emission and absorption bands of 32S2, 34S2, and 32S34S. The three curves extrapolate to identical limits, at 35 999.0 ± 2.5 cm−1 above the minimum in X3Σg−. The predissociating state is thereby identified as a 1u state, and arguments based upon (i) the noncrossing rule for states of like Ω and (ii) a comparison of the observed shapes of the limiting curves with those calculated on the basis of long-range forces, indicate that the products at this limit are S(3P2) + S(3P1). D00 (32S2) is then 35 216.4 ± 2.5 cm−1, or 100.69 ±.01 kcal mole−1.
Multiple ionization in carbon monoxide by successive electron impacts
Authors: Redhead P. A.
Published: April 2011

Appearance potential curves for the multiply-charged ions of carbon and oxygen (up to C4+ and O6+ for electron energies less than 200 eV) have been measured in two mass spectrometers fitted with trapped-ion sources. Trapping of the C+ and O+ ions is not as efficient as for ions produced without dissociation because of the initial kinetic energies of the dissociatively produced ions. The predominant collision sequences involve the formation of CO+ as the first step rather than the dissociative ionization of CO. Ionization potentials estimated from measured appearance potential curves are in agreement with spectroscopically determined values. Most of the other breaks that were repeatedly observed in the appearance potential curves are in reasonable agreement with energy-limiting steps in the collision sequences corresponding to transitions between spectroscopically known energy levels of the ions. Two observed transitions (in O4+ and O5+ appearance potential curves) cannot be explained in terms of spectroscopically known energy levels and may result from highly-excited, long-lived states of O2+ and O4+, respectively. The threshold of the C4+ appearance potential curve indicates the existence of a metastable state of C3+ not previously observed.
The hydrogen molecule—comparison between theory and experiment
Authors: Wilkinson P. G. , Pritchard H. O.
Published: April 2011

The experimental and theoretical data on the X1Σg+, B1Σu+, and C1Πu states of H2, HD, and D2 are reviewed and an attempt is made to assess their respective reliabilities. Even where the data can be considered reliable, three kinds of discrepancy occur: (i) the total theoretical binding energy of the v = 0 state of X1Σg+ is too great, in contradiction to the variation theorem; (ii) the theoretical vibrational spacings are always too large; (iii) the theoretical rotational spacings for X1Σg+ are in good agreement with experiment, but for higher states there is a systematic disagreement between theory and experiment. It is concluded that (i) could be accounted for either by an error in the relativistic part of the theory or in the experiment; (ii) can only be accounted for by an error in the theory, probably in the nonrelativistic part; and (iii) simply results from the neglect of nonadiabatic coupling in the upper excited electronic states. In conclusion, new experiments and new calculations are recommended with a view to resolving these discrepancies.
Equilibrium fluctuations in magnetic systems
Authors: Burgess Ronald E.
Published: April 2011

The thermodynamic treatment of equilibrium fluctuations in magnetic systems is discussed and applied to a variety of situations. The spectral density of the magnetic moment or flux is derived for simply-connected bodies (sphere and cylinder) and for multiply-connected systems (loop and hollow cylinder). The material is considered to be either a normal conductor, a superconductor, or a ferromagnet. The results are valid in the presence of a static magnetic field and also if the susceptibility is field dependent. No abrupt change in fluctuations occurs as a superconductor is taken through the transition temperature. The introduction of a Josephson junction or a resistive link in a superconducting loop is shown to increase the flux fluctuations markedly with a steady increase as the link is made weaker. At high frequencies the fluctuation spectrum for a superconductor approaches that for the same system in the normal state. A sum rule for the moment fluctuations is derived and related to the difference of the initial and final responses of the system to an abrupt change of external magnetic field.
Charged particlelike solutions of the nonlinear system Fik,k = −(1 + Ak2)Ai
Authors: Darewych J. W. , Schiff H.
Published: April 2011

We consider static charged particlelike solutions of the nonlinear electromagnetic theory Fik,k = −(1 + Ak2)Ai. A discrete set is determined by requiring the Lagrangian to be an extremum with respect to the parameters characterizing the continuum of solutions. Spherically symmetrical solutions are obtained numerically, as well as the corresponding charges and masses. Nonspherical solutions and variational approximations are discussed briefly.
Transport properties of pure metals at high temperatures. II. Silver and gold
Authors: Laubitz M. J.
Published: April 2011

The high-temperature transport properties of silver and of gold have been determined and are here reported. The measurements extend from 300 to 1100 °K for silver, and from 300 to 1200 °K for gold. Two conclusions are drawn from the measured thermal conductivities and electrical resistivities: (i) the computed Wiedemann–Franz ratio does not reach the standard (Sommerfeld) value, even at the highest temperatures investigated and (ii) the observed temperature variation of these two properties cannot be explained simultaneously on the basis of the Bloch scheme of the free-electron model, or even a generalization thereof. A full discussion of the possible reasons for this behavior will be given in a subsequent paper.New absolute thermoelectric power data for platinum are derived from the measured relative powers of the noble metals; these show considerable deviations from previously reported data, but are believed to be more representative of currently available high purity platinum.
Low-energy cosmic X-ray measurements
Authors: Baxter A. J. , Wilson B. G. , Green D. W.
Published: April 2011

An experiment is described to investigate cosmic X rays in the energy range 0.25–12 keV. The data-recovery system and methods of spectral analysis are considered. Results are presented for the energy spectrum of the diffuse X-ray component and its distribution over the northern sky down to 1.6 keV with a limited extension at 0.27 keV.In the energy range 1.6 to 12 keV, the spectrum is represented by:[Formula: see text]although separate analyses indicate a flattening below 4.5 keV to give:[Formula: see text]and[Formula: see text]At the lowest energies, the flux appears to increase more rapidly and exhibits some anisotropy in arrival directions related to the gross galactic structure. Spectral characteristics of the Crab Nebula and Cygnus X-2 have also been determined.
Radiation-induced shocks in oxygen
Authors: Zuzak William W. , Ahlborn Boye
Published: April 2011

The formation of pressure waves, induced by the absorption of radiation in the Schumann–Runge continuum of oxygen, was studied experimentally and theoretically. The 10-μs radiation pulse, produced by a capillary discharge at a color temperature of 6 × 104 °K, passed through an LiF window into a test chamber containing oxygen. Surprisingly, the propagation velocity of the pressure waves was found to be independent of the initial filling pressure p0 (v = 364 ± 8 m/s); however, as expected, their point of formation behind the LiF window varied inversely as p0. The evolution of the pressure waves was computed numerically on the basis of a simplified model and the method of characteristics modified to include the radiant-energy input. It appears that the wave is driven for some time after the decay of the radiation pulse by release of frozen dissociation energy.
Topside observation of electron density variations (G-condition) at times of low magnetic activity
Authors: Herzberg L. , Nelms G. L. , Dyson P. L.
Published: April 2011

The so-called G-condition of the ionosphere (foF2 < foF1, with normal foF1) is investigated from the topside with the Alouette II satellite. In the absence of a severe magnetic disturbance, the condition is occasionally observed over a path length of the order of a thousand kilometers. In this case, one observes a characteristic development: in the F2 region at the levels below about 1000 km there is a systematic decrease of electron density to about one-half the original value, followed by a gradual increase to normal, and at the levels above about 1000 km there is a corresponding increase, followed by a decrease back to normal. This variation in electron density is accompanied, at levels below 2000 km, by significant increases in scale height. Cylindrical electrostatic probes carried on the satellite show, at the same time, increases in electron temperature. Possible interpretations of the observational data are discussed.
Studies of the ionic ferromagnet (LaPb)MnO3 II. Static magnetization properties from 0 to 800 °K
Authors: Leung L. K. , Morrish A. H. , Searle C. W.
Published: April 2011

The static magnetization of the family of compounds La1−xPbxMnO3(0.25 < x < 0.45) has been measured from close to absolute zero to about 800 °K. The compounds are ferromagnetic, with Curie temperatures ranging from 315 to 350 °K. At absolute zero, the magnetization agrees to within 3% of that expected from the average spin per formula unit. The spontaneous magnetization decreases more rapidly than predicted by the Brillouin function for a normal ferromagnet for 0.9 < T/Tc < 1. Just above the Curie temperature, the reciprocal susceptibility versus temperature curve exhibits a slight curvature; at higher temperatures the susceptibility follows the Curie–Weiss Law. The average spin obtained from the Curie constant agrees well with that obtained from the chemical formula. It is concluded that the ferromagnetism has its origin primarily in the itinerant d electrons that lie in a narrow double-exchange band, although lattice distortion may also have an influence.
Studies of the ionic ferromagnet (LaPb)MnO3 III. Ferromagnetic resonance studies
Authors: Searle C. W. , Wang S. T.
Published: April 2011

Ferromagnetic resonance has been observed in single crystals of the family La1−xPbxMnO3with 0.25 < x < 0.45 from 13 to 25 GHz and in the temperature range from 77 to 430 °K. The line width, ΔH, exhibits a sharp minimum accompanied by an isotropic shift in the resonance line at a critical temperature, Tc. Tc is dependent on the concentration of Mn4+ and has been related to the Curie temperature. The shift in the peak of the resonance line at Tc can be described by effects related to the formation of a spin-polarized conduction band. The line shape is asymmetric at high temperatures, ~Tc, and at low temperatures, T ~ 77 °K. This asymmetric behavior of the line is probably due to transport properties of the conduction-band electrons.
The Percus–Yevick approximation near the triple point of argon
Authors: Watts R. O.
Published: April 2011

The radial distribution function and thermodynamic properties of argon are calculated using the (12, 6) potential and the Percus–Yevick approximation. The results are compared with experimental values for argon, the machine calculations of Verlet and of McDonald and Singer, and with the perturbation theory of Barker and Henderson.
On the image representation of the quasi-static fields of a line current source above the ground
Authors: Wait James R. , Spies Kenneth P.
Published: April 2011

It is shown that the influence of the homogeneous conducting half-space can be represented approximately in terms of an image source located at a complex depth.
Further studies on the collision-induced absorption of the fundamental band of hydrogen at room temperature
Authors: Varghese G. , Reddy S. Paddi
Published: April 2011

The collision-induced infrared absorption of the fundamental band of hydrogen in H2–O2 and H2–Xe mixtures was studied at room temperature at a path length of 105.2 cm at pressures up to 250 atm for different base pressures of hydrogen. The enhancement absorption profiles of the band in H2–O2 mixtures show the usual features of collision-induced absorption. However, the enhancement profiles in H2–Xe mixtures show some interesting new features. These are: the separation between the peaks of the two components of the Q branch remains almost constant with increasing density of the mixture; at all densities, the intensities of these two peaks are almost equal; and the lines of the quadrupolar branches O and S are more pronounced than those in any other binary mixture of hydrogen studied previously. Integrated absorption coefficients were measured for each of the mixtures and the binary and ternary absorption coefficients were derived. The values of the binary coefficients are 6.12 × 10−35 cm6 s−1 for H2–O2, and 11.34 × 10−35 cm6 s−1 for H2–Xe. The ternary coefficient is zero for H2–O2, whereas it has a large negative value for H2–Xe.
A tabulation of the 6-j symbols
Authors: Saxena K. M. S. , Malli Gulzari
Published: April 2011

Wigner's 6-j symbols [Formula: see text] are calculated and tabulated beyond the limit j1's or l1's = 8 and up to the limit j1's or l1's = 11 of the arguments for general usage in calculations in various fields of physics, especially in nuclear and atomic spectroscopy. One of the most complete existing tabulations of the 6-j symbols is that of Rotenberg et al. which gives these symbols up to the limit j1's or l1's = 8 only.
Effect of the pigmy resonance on the calculations of the neutron capture cross section
Authors: Brzosko J. S. , Gierlik E. , Soltan Jr. A. , Wilhelmi Z.
Published: April 2011

A comparison of the experimental cross sections of the (n, γ) reaction for several nuclei (103Rh, 127I, 181Ta, 197Au) with the compound nucleus model calculations has been made. In the formula used for the probability of gamma-ray emission from the compound nucleus, the presence of the well-known giant resonance was accounted for, as well as the presence of the "pigmy resonance" appearing at the energy Eγ ≈ 6 MeV. The agreement with the experimental values is better in this case than when the "pigmy resonance" is neglected. The same conclusions can be obtained from the calculations of the shape of the spectrum of neutron capture and from the Γγ/D ratio.
Interpretation of the visible and near-infrared absorption spectra of compressed oxygen as collision-induced electronic transitions
Authors: Tabisz G. C. , Allin Elizabeth J. , Welsh H. L.
Published: April 2011

The intensity profiles of some of the broad continuous absorption bands of oxygen in the near-infrared and visible regions were measured in the compressed gas over a range of pressures and temperatures. Three single electronic transitions (12 600, 10 600, 07620 Å) and three double transitions (6290, 5770, 4770 Å) were studied in detail. The asymmetry of the band profiles is shown to arise from a Boltzmann relation between the intensity distributions in the high and low frequency wings when the band origin is properly chosen. By assuming an appropriate rotational structure and broadening each rotational transition by a Boltzmann-modified dispersion curve the profiles of the bands could be reproduced with only minor discrepancies. These criteria, along with the well-known quadratic density dependence of the intensity, show that the bands are properly interpreted as collision-induced electronic transitions. The large width of the translational broadening functions required in the analysis indicates that the induction must be predominantly due to overlap interaction. No specific effects of (O2)2 complexes are identifiable in the spectra.
Electronic Raman effect of nitric oxide at high resolution
Authors: Fast H. , Welsh H. L. , Lepard D. W.
Published: April 2011

The rotational Raman spectrum of gaseous NO was photographed with a spectral resolution of ~0.3 cm−1. In longer exposures the rotational structure of the electronic transition, [Formula: see text], was also observed. It consists of O, P, Q, R, and S branches and has an intensity distribution in accordance with theory.
Binding energy of the alpha particle with tensor forces and a velocity-dependent potential
Authors: Jain S. C.
Published: April 2011

The results of a variational calculation for the binding energy of the alpha particle with the tensor velocity-dependent potential of Werner and the Irving wave function, containing a mixture of the principal 1S0 and 5D0(1) states are presented. A binding energy of 28.03 MeV for the alpha particle is found, which is in excellent agreement with experiments, but the r.m.s. radius obtained in this way is about 88% of the experimental value.
Etalonnage de polygones optiques par interférométrie en lumière laser
Authors: Bouillon Gratien , Tremblay Gilles , Delisle Claude
Published: April 2011

It is current practice to use autocollimators to calibrate optical polygons. An interferometric method in laser light is described.
Influence of annealing on the electrical conductivity of single crystals of Cu2O
Authors: Weichman F. L. , Kužel R.
Published: April 2011

A series of conductivity measurements were made on single crystals of Cu2O from 20 to 840 °C to explain the various activation energies which appear at different temperatures and oxygen pressures. Crystals were annealed in the 10−8 and 10−4 Torr region in the stability ranges of Cu2O, Cu, and CuO at various temperatures. For the low-temperature activation energies ranging from 0.60 to 0.26 eV, an excellent agreement with the empirical Meyer–Neldel rule was found. The highest activation energy of 1.12 eV in the 570 to 680 °C range at 10−8 Torr is associated with the boundary between the two stable phases Cu and Cu2O. The changes in defect concentration are ascribed to the mechanism of self-compensation. The energy-level diagram proposed by Bloem is adequate to explain the present results.
Anomalous density dependence of the v1 band of carbon dioxide in pressure-induced absorption
Authors: Mannik L. , McKellar A. R. W. , Rich N. , Stryland J. C.
Published: April 2011

The anomaly in the density variation of the integrated absorption of the pressure-induced v1 band of carbon dioxide is shown experimentally to be represented by a linear term in the density expansion of the intensity, which is important only in the lower density region (0–20 amagat). A calculation indicates that the linear term arises from the infrared-active absorption of the v1 band of C16O18O.
Wave-number dependence of the static screening function of an interacting electron gas. II. Higher-order exchange and correlation effects
Authors: Geldart D. J. W. , Taylor Roger
Published: April 2011

An interpolation formula is suggested for the wave-number and density dependence of the static screening function for an interacting electron gas in its ground state. The approximate screening function simulates a number of properties of the exact screening function which have been established by analysis of its many-body perturbation expansion. The accuracy of the interpolation formula is discussed and is considered to be adequate for practical calculations in the range of intermediate metallic densities.