bluuebunny/crossref_metadata_2025 huggingface dataset:
Single electron capture by N12+ in rare gas targets between 60 keV and 200 keV
Authors: Hird B. , Suk H. C. , Ali S. P.
Published: April 2011

Charge exchange measurements in thin targets of the rare gases by a N2+ beam have been made between 60 keV and 200 keV. The singly charged ions produced in the collisions are expected to be produced in only a few allowed states, and a Rapp and Francis type calculation for the weighted average cross section to these allowed states was found to have generally the correct energy dependence but to be too small by a factor which increased from 4 in He to more than 10 in Xe. There was some evidence that the 4P state of N2+ may have been present in the beam in varying amounts.
The preparation and passive annealing of Cd3As2 platelets
Authors: Rambo A. , Aubin M. J.
Published: April 2011

Single crystals of Cd3As2 have been grown from the vapour phase using hydrogen gas and then annealed under vacuum at 425 °C. The anneal of thin samples always causes the Fermi energy to rise to 0.25 eV (n ~ 3.3 × 1018/cm3). The latter then decreases at a rate of 1.5–5 meV/week to 0.052 eV(n ~ 1.5 × 1017/cm3) or lower.
Symmetry in (H2)2, (D2)2, (HD)2, and H2–D2 Van der Waals complexes
Authors: Bunker P. R.
Published: April 2011

The molecular symmetry group of the Van der Waals complex (H2)2 or (D2)2 is a group of order 16 called G16. This group is used to symmetry label the rotation–vibration states and the nuclear spin states of the complexes; the nuclear spin statistical weights are also determined. The group is used to classify the terms in the expansion of the dipole moment function and to determine the symmetry restrictions for allowed electric dipole transitions. The complex H2–D2 has a molecular symmetry group of order 8, G8, and (HD)2 a group of order 4, G4; the energy level symmetries, statistical weights, and selection rules for these complexes are also determined.
Detection of the FO radical by CO2 laser magnetic resonance
Authors: McKellar A. R. W.
Published: April 2011

The fundamental vibrational band of the elusive free radical FO has been detected using the technique of CO2 laser magnetic resonance in the 1025–1043 cm−1 region. The FO was produced by a discharge in CF4 gas flowing in a fused quartz (SiO) tube, and the resulting spectra were strong enough to allow the resolution of saturated absorption dips and 19F nuclear hyperfine structure. Seven different CO2 laser lines were used to observe six vibration–rotation transitions, all belonging to the Ω = 3/2 component of the 2Π ground electronic state. The analysis of these observations yielded the first experimental determinations for FO of the rotational constant B, centrifugal distortion constant D, fine structure constant A, and axial hyperfine constant h, as well as the vibrational dependences of B and h. The bond length of FO was found to be re = 1.35789 ± 0.00025 Å, which is 1.5 to 2.7% larger than previous values given by ab initio calculations.
A remark on Moore's new method of obtaining approximate solutions of the Dirac equation
Authors: Tomishima Yasuo
Published: April 2011

The new method for obtaining an approximate solution of the Dirac equation proposed by Moore is applied rigorously in zero order to the hydrogenic atom, and the results are compared with the exact solution and with those obtained by Pauli's approximation. It is concluded that up to the order of α2 the three methods give the same energy values, but the higher order contribution included in Moore's method makes the energy worse than Pauli's. Moore's zeroth approximate wave function is also examined.
On the differential scattered power due to the nonlinear scattering of light for ultra strong fields
Authors: Valluri S. R. , Bhartia P.
Published: April 2011

The differential scattered power is calculated for the nonlinear interaction of two electromagnetic waves in a vacuum. It is calculated for both parallel [Formula: see text] and perpendicular [Formula: see text] polarization cases and expressed as a function of the scattering angle θ′. In an earlier paper we have treated the nonlinear interaction by the introduction of the Lagrangian for the ultrastrong field case. A detailed discussion of the power indicates the position of the maxima and minima at various angles and hence would enable the experimentalist to set up the required orientation of the detecting apparatus. The promise of continuous, intense, and monochromatic polarized radiation from electron synchrotrons and storage rings motivates the study and experimental confirmation is hoped for.
Effect of the third-order contribution on ion-acoustic solitary waves
Authors: Lai C. S.
Published: April 2011

The effect of the third-order corrections on ion-acoustic solitary waves is studied on the basis of the reductive perturbation method. The secular terms in the third-order approximation are eliminated by employing the renormalization scheme of Kodama and Taniuti in an unambiguous manner. It is found that the contribution of the third-order corrections to the soliton velocities and widths is rather minimal.
Fringe control techniques applied to holographic non-destructive testing (HNDT)
Authors: Shakher Chandra , Sirohi R. S.
Published: April 2011

The fringe control techniques applied to holographic non-destructive testing using real-time hologram interferometry are discussed. These techniques are of immense importance for removing high spatial frequency fringe pattern arising as a result of overall motion or gross structural deformation of the object when it is subjected to load. The removal of high spatial frequency fringe pattern is essential to view the regions of defect in the object distinctly. Experimental results are presented to support theoretical predictions.
Electrodynamics of charged scalar solitons
Authors: Morris T. F.
Published: April 2011

The electrodynamics of a nonlinear, complex scalar field is developed from the basis of a Hamiltonian formalism. By means of a canonical transformation, the equations for a stationary state are reduced to the consideration of an equivalent problem in static equilibrium. Localized solutions are defined. For specified conditions on the self-interaction, solutions of finite energy, and finite, nonzero charge, are localized.
Brillouin scattering studies of simple liquids: O2, N2, CO, CH4
Authors: Clouter M. J. , Kiefte H. , Morgan I. E.
Published: April 2011

The technique of Brillouin scattering has been used to obtain new velocity and attenuation data for thermal sound waves in liquids O2, N2, CO, and CH4. Measurements of Brillouin shift and linewidth were made along the liquid–vapor coexistence line in each case and, when combined with previously published results, comprise a reasonably complete set of data covering the saturated liquid ranges of all four cryogenic materials. Where possible, comparisons are made with corresponding ultrasonic data.
Relativistic spin–spin interaction of two concentric shells
Authors: Pechlaner E.
Published: April 2011

We investigate, in the framework of general relativity, a system consisting of two concentric shells of arbitrary thickness, spinning with angular velocity vectors ω and [Formula: see text], respectively. We use Einstein's linearized theory to define a total torque and total force acting on a body and find an interaction torque between the two bodies, proportional to [Formula: see text], which has no analogue in Newtonian mechanics.The angular velocity vectors of the earth's mantle and core make an angle of about 10−5 rad. With above system as a model for the earth, the relativistic interaction torque is about 4 × 1021 dyn cm.If a pulsar's crust and core have non-aligned axes of rotation, the relativistic torque alone will produce precession with a period of about 1 h.
Light angular distribution and modulation transfer function of a fluorescent screen excited by an electron beam
Authors: Giakoumakis G. E. , Nomicos C. D. , Euthymiou P. C.
Published: April 2011

The angular distribution of the light emitted from a ZnCdS(Ag) phosphor screen excited by an electron beam is measured for different thicknesses of the screen and for two grain sizes. This angular distribution is found to have a divergence from the Lambert law. A theoretical model is proposed leading to an equation fitting to the experimental results. Using this equation the modulation transfer function (MTF) of the screen was calculated.
A fast method of LEED/MEED intensity calculation for the study of diatomic surfaces
Authors: Masud Nazma
Published: April 2011

The interchain scattering formula of LEED/MEED intensity calculations for the study of metal surfaces is generalized to study diatomic surfaces. The efficiency of the method is investigated by comparing the results of intensity calculations for the NaCl (100) surface structure with those obtained from the layer-KKR method. We find that the interchain scattering formula for diatomic surfaces has several computational advantages over the layer-KKR method and can be used to extend the calculation to higher incident energies.
(Anti)-neutrino–deuteron scattering and the structure of the weak hadronic neutral currents
Authors: Rahman Mahfuzur
Published: April 2011

Neutrino(antineutrino)–deuteron elastic and neutral current breakup processes are studied to provide information about the structure of the weak hadronic neutral currents. The scattering cross sections for these processes have been calculated with the help of the impulse approximation. Thus, we have additional input for the determination of the weak hadronic neutral current couplings. Some of the popular models can be put to test as they give distinguishable predictions for these processes. Also since the deuterium filled bubble chambers will be exposed to neutrino beams, our results may serve as a guide as to what to expect theoretically.
Chemiluminescence from oxidation of inorganic hydrides: spectrum of TeF
Authors: Newlin Donald E. , Stewart Gerald W. , Gole James L.
Published: April 2011

The chemiluminescence which results when hydrogen telluride and fluorine are intimately mixed corresponds to an emission spectrum in the region 3900–5200 Å which appears to result from the previously unobserved TeF radical. The structure of the vibronic bands arising from transitions between 2Πi states has been assigned by analogy with the similar SF spectrum. The spectra corresponding to the A2Π3/2–X2Π3/2 and A2Π1/2–X2Π1/2 band systems appear to be well fit using the electronic and vibrational parameters T0(3/2–3/2) = 21 218 cm−1, T0(1/2–1/2) = 21 612 cm−1, we′ = 399 cm−1, wexe′ = 2.4 cm−1, we″ = 603 cm−1, and wexe″ = 4.0 cm−1. The difference in spin orbit constants for the ground and excited states is calculated to be 394 cm−1.
Squishy proteins in fluid membranes
Authors: Bloom Myer
Published: April 2011

A variety of experiments indicate that proteins hardly perturb the orientational order of phospholipids in biological membranes. It is suggested that, in common with soluble proteins, integral proteins in membranes have a "fluid-like" outer region which provides an approximate fluid mechanical match with the liquid crystalline phospholipid membrane.
An exactly soluble three-body problem in one dimension
Authors: Jung C.
Published: April 2011

An exactly soluble one-dimensional three-body problem is presented, in which the interaction between the particles consists of local two-body potentials between each two particles. Infinitely high step functions are chosen for the form of the three potential functions. This interaction allows only three-body bound states and no continuum states. We have considered three different choices of the mass ratios of the three particles and we give formulas in closed form for the energies and for the wavefunctions of all states.
Cosmological solution with matter in a new theory of gravitation
Authors: Kunstatter G. , Moffat J. W. , Savaria P.
Published: April 2011

We present a plane-symmetric, homogeneous solution with matter in a theory of gravitation based on a non-symmetric Hermitian metric. The solution describes a universe which begins with finite 4-curvature, energy density, and temperature. The initial temperature [Formula: see text] depends on a new parameter κ in the theory. An analysis of primordial helium abundance gives rise to a lower bound [Formula: see text]. The resulting cosmology is consistent with all presently known observations.
Revised and extended analysis of Cd IV
Authors: Joshi Y. N. , Kleef Th. A. M. van , Mazzoni M.
Published: April 2011

The spectrum of cadmium was photographed in the region 500–2100 Å using a 10.7 m normal incidence spectrograph and a 6.65 m normal incidence spectrograph. The sources used were a triggered spark and a sliding spark. The earlier analysis has been revised and extended. All levels of the 4d85s and 4d85p configurations have been determined. Parametric level fitting calculations support the analysis. Three hundred and seventeen lines have been classified in this spectrum of which 209 are new lines.
Energy flow vector of the electromagnetic field
Authors: Wallace G. L. , O'Connell R. F.
Published: April 2011

Poynting's choice for the energy flow vector of the electromagnetic field has certain unattractive physical features. In order to eliminate such features Hines proposed an alternative choice. Here we show that Hines's choice does not lead to Larmor's result for the rate of radiation by an accelerated non-relativistic charge.
Influence de la lumière du jour et de l'épaisseur sur la conductivité de la phtalocyanine de fer
Authors: Crine Jean-Pierre , Bélanger Guy
Published: April 2011

We show that the electrical conductivity of annealed iron phtalocyanine is sensitive to prolonged exposure to daylight, and that this dependence is then a function of the thickness. A charge photogeneration model is proposed to explain the observed behaviour.[Journal translation]
An orthogonalized plane wave pseudopotential model calculation of the dilational strain dependence of the Fermi surface of white tin
Authors: Mak D. K. , Perz J. M.
Published: April 2011

The response of the Fermi surface of white tin to uniaxial dilational strain has been determined from an orthogonalized plane wave (OPW) pseudopotential model. The model parameters have been chosen to give a best fit to experimental data on the Fermi surface in the unstrained metal. The strain derivatives of a total of 17 extremal cross sections, normal to the symmetry directions [001], [100], and [110] in the tetragonal crystal, have been calculated. The results for large orbits are found to be generally in good agreement with experimental data; the agreement is only qualitative for orbits on small pieces of the Fermi surface. Properties of the minimal orbit around the re-entrant neck in zone four have been determined; these explain why de Haas – van Alphen oscillations from this orbit have until recently eluded observation.
Electron transfer measurements from rare gas targets to O12+ ions between 60 and 200 keV
Authors: Hird B. , Ali S. P.
Published: April 2011

Charge exchange measurements in thin targets of the rare gases by an O2+ beam have been made between 60 and 200 keV. Taking into account the relative weighting of the final states which are allowed assuming spin, symmetry, and Λ conservation it was found that a crossing theory of the Landau–Zener type is completely inadequate to account for the cross sections of the heavier targets, whereas a non-crossing theory in the Rapp–Francis formulation was found to give good fits, both in energy dependence and overall magnitude, to the cross sections except for the xenon target where it is too small by a factor of 2. The improvement in fit is due to the inclusion of a factor which was omitted in the original formulation of Rapp–Francis, and also the inclusion of many states of the product ions in the calculation.
Phonon resonances and infrared absorption due to interstitial F− ions and substitutional trivalent cations
Authors: Nerenberg M. A. H. , Govindarajan J. , Jacobs P. W. M. , Haridasan T. M.
Published: April 2011

A Green's function formulation is developed to compute the phonon resonances of an F− interstitial perturbed by the presence of a trivalent cation which occupies one of the second neighbour sites of the interstitial in BaF2, the interstitial site symmetry being thereby reduced from Oh to C4v. Expressions for the absorption coefficient are obtained for the case of an isolated interstitial and for that of the interstitial with an adjacent trivalent cation. These expressions are evaluated for both the isolated interstitial and for Fi− associated with Y3+, Gd3+, or La3+. There is reasonable agreement between theory and the experimentally observed infrared absorption spectra measured by Morlot, Hadni, Villermain-Lecollier, and Strimer.
Static paramagnetic response of thin soft superconductors
Authors: Piyakis K. N. , Papini G. , Rystephanick R. G.
Published: April 2011

We calculate the static paramagnetic response of thin superconductors of the first kind to terms proportional to a static external magnetic field and a static scalar potential. The response is in the form of a current. The corresponding magnetic field is calculated for a thin cylindrical shell and is proportional to the electrochemical potential.
Calculation of second virial coefficients for nitrogen and carbon monoxide
Authors: Whitmore M. D. , Goodings D. A.
Published: April 2011

The classical second virial coefficients B(T) for nitrogen and carbon monoxide have been calculated exactly as a function of temperature for three different realistic models of the intermolecular potential. The potential models, due to Kohin, Raich and Mills, and Raich and Gillis, differ mainly, but not solely, in the way in which they represent the short-range Coulomb repulsion between molecules. As this interaction depends on the molecules' shapes, it is highly anisotropic. To ensure good accuracy in the results for B(T) the angular and radial integrals were performed by suitable Gaussian integration methods.The contributions to B(T) of various anisotropic terms are considered, and a power series expansion in terms of the anisotropic part of the potential discussed. The calculated results are compared with experiments, and some general conclusions drawn.
A study of planarity in inelastic hadron–hadron interactions at accelerator energy
Authors: Ghosh Dipak
Published: April 2011

This paper presents a first investigation of the planarity effect in inelastic hadronic reactions at 70 GeV/c with the help of 'principal axis' variables. It has been observed from the analysis of emulsion data of proton–nucleon interactions at 70 GeV/c that the planarity effect is prominent in the case of low multiplicity events and this effect decreases with the increase of multiplicity.
The collision-induced translational spectrum of CF4–He gas mixtures
Authors: Afanasev A. D. , Bulanin M. O. , Tonkov M. V.
Published: April 2011

The collision-induced far infrared spectrum of CF4–He gas mixtures was measured at 213 K. It is shown that the observed enhancement of the absorption represents the translational spectrum induced by isotropic overlap forces. The band shape calculations are consistent with the assumption that the collision-induced dipole moment varies exponentially with intermolecular separation, and the parameters of the dipole moment function have been determined.
Mode-locking observation of a CO2 laser by intracavity plasma injection
Authors: John P. K. , Dembinski M.
Published: April 2011

A TEA CO2 laser was simultaneously Q-switched and mode-locked when an underdense plasma was injected into the cavity. The plasma was produced in an electromagnetic shock tube. Plasma density and temperature were Ne ~ 1017 cm−3 and Te ~ 2 eV, respectively. Phase perturbation of the cavity due to the time dependent plasma refractive index could account for the observed mode-locking.
The physics of meron pairs. I. Introduction, motivation, and formalism
Authors: Laughton David G.
Published: April 2011

The physics of meron pairs is considered in this series of papers. The first paper presents the motivation for focussing on this particular type of field configuration as an important degree of freedom in the SU(N) Yang–Mills theory. It also outlines the formalism for doing a saddle point expansion of path integrals about configurations which are constrained minima of the action (such as meron pairs) as opposed to local minima (such as instantons). The formalism is illustrated by the treatment of an ordinary integral which is analogous to the meron pair region of the Yang–Mills path integral. It is found that the expansion about constrained minima depends to leading order on the constraints chosen to partition the integral. This means that some criteria must be found for the choice of constraints. This problem is discussed. The actual meron pair calculations are partially described here and done in the second and third papers. Applications are to be considered in any subsequent papers.
The physics of meron pairs. II. The bare activity
Authors: Laughton David G.
Published: April 2011

In this second paper of the series, the details are given of the calculation of the bare activity of the meron pairs described in the first paper. The instanton limit is computed and found to be consistent with the discussion presented in the first paper. The bulk of the calculation for the regime of physical interest is performed using one set of constraints. An outline is given of one possible treatment of an instability in the calculation in part of this regime. A detailed analysis of this instability, a more detailed consideration of other constraint systems, and some further numerical work are left for the third paper.
Spin-exchange scattering cross sections for hydrogen atoms at low temperatures
Authors: Berlinsky A. J. , Shizgal B.
Published: April 2011

Calculations are presented of the low energy (0 < E ≤ 10−2 eV) spin exchange and frequency shift cross sections for (H,H) scattering, and of their thermal averages for 0 < T < 10 K. In particular, the behaviour of the cross sections in this low energy limit and the role of resonances due to orbiting collisions is studied in detail. A comparison is made with recent nmr measurements on gaseous atomic hydrogen at liquid helium temperatures. The results of this work suggest further useful experiments at low temperatures.
Comment on "Macroscopic theory of dielectric solids. I. The model of molecular optics"
Authors: Unruh W. G.
Published: April 2011

A mean polarization distribution function is defined and used to simplify the derivation given by Sipe of the constitutive relation in solids.
On the derivation of the constitutive relation of an amorphous solid
Authors: Sipe J. E.
Published: April 2011

We present an improved derivation of the constitutive relation of an amorphous solid. By a slightly different treatment of the radiation reaction fields, we avoid the necessity of introducing "counting relations" of the sort that have been required in earlier derivations.
A nuclear magnetic resonance study of InBi single crystals
Authors: Kaplan N. , Sharma S. N. , Williams D. Ll.
Published: April 2011

A nuclear magnetic resonance study of 115In in a single crystal of InBi has enabled the direct determination of the isotropic and anisotropic Knight shifts as well as the quadrupole interaction over the temperature range between 1.2 K and room temperature. An essentially linear variation with temperature is obtained for all three parameters with both the quadrupole interaction and the isotropic Knight shifts undergoing sign reversals in this temperature range. Comparisons are made with earlier nmr and time differential perturbed angular correlation (TDPAC) studies as well as with band structure predictions.
Van der Waals and repulsive interactions in the crystal structure of heavy alkali metals
Authors: Upadhyaya J. C. , Wang S. , Moore R. A.
Published: April 2011

The present work deals with the calculation of a screened van der Waals contribution to the binding energy of heavy alkali metals, namely K, Rb, and Cs. Our calculations show that the van der Waals contribution is of the order of energy difference between different phases for a heavy alkali metal. Further we study the effect of the Born–Mayer type repulsive interactions on the crystal structure for heavy alkalis. It appears from this study that these repulsive interactions are important in the determination of the crystal structure, particularly for a heavy alkali metal under high pressures.
High resolution rotation–vibration Raman spectra of acetylene. II. The spectra of C2D2 and C2HD
Authors: Kostyk E. , Welsh H. L.
Published: April 2011

The Raman spectra of gaseous C2D2 and C2HD were excited in a multiple-reflection Raman cell by a single-moded Ar+ laser and recorded photographically; the gas pressures were in the range, 130–200 Torr, and the spectral slit width was ~ 0.1 cm−1. The ν1, ν2, and ν41 bands of C2D2 and the ν1 and ν2 bands of C2HD were recorded. These were analyzed to give the band origin, ν0, and the upper state constants, B1 and D1; accurate infrared values of the ground state constants, B0 and D0, were assumed in the analyses. Values of the rotation–vibration interaction constants, αi, assembled from Raman and infrared studies of C2H2, C2D2, and C2HD, were used to calculate the equilibrium internuclear distances for the acetylene molecule: re(C—H) = 1.06250 ± 0.00010 and re(C≡C) = 1.20241 ± 0.00009 Å.
Finite spatial volume approach to finite temperature field theory
Authors: Weiss Nathan
Published: April 2011

A relativistic quantum field theory at finite temperature T = β−1 is equivalent to the same field theory at zero temperature but with one spatial dimension of finite length β. This equivalence is discussed for scalars, for fermions, and for gauge theories. The relationship is checked for free field theory. The translation of correlation functions between the two formulations is described with special emphasis on the nonlocal order parameters of gauge theories. Possible applications are mentioned.
Vibrational analysis of the 3Π1–X1Σ+ band systems of SiCl+
Authors: Tsuji Masaharu , Mizuguchi Toshinori , Nishimura Yukio
Published: April 2011

The emission spectrum of the SiCl+ radical cation, excited by the thermal energy He+ + SiCl4 reaction, has been observed and vibrationally analyzed in the 310–350 nm region. The two new subband systems, [Formula: see text] and a3Π1–X1Σ+, have been identified. The vibrational assignments were confirmed by the observed isotope band heads of Si35Cl+ and Si37Cl+. The following molecular constants (in cm−1) have been obtained for the X1Σ+, [Formula: see text], and a3Π1, states.[Formula: see text]
Scattering of light due to the density fluctuations in the interface region of a liquid–vapor system
Authors: Peternelj J.
Published: April 2011

This paper is concerned with the scattering of light due to the density fluctuations in an inhomogeneous fluid. In particular, we calculate the angular and frequency distributions of the scattered radiation in the presence of density fluctuations confined to the interface region of the liquid–vapor system in thermal equilibrium. It is found, that even in the absence of fluctuations, the effect of the continuous interface is to produce a small ellipticity of the reflected light near the Brewster angle, assuming that the incident light is linearly polarized.
A campaign to study pulsating auroras
Authors: McEwen D. J. , Duncan C. N.
Published: April 2011

A campaign involving some 25 scientists from Canada and Japan was conducted in northern Saskatchewan in January–February 1980 to study pulsating auroras. Ground based optical and radio measurements were carried out during 34 nights in two successive dark moon periods; 8 of these nights provided good data on pulsating auroras. Two rockets were flown into pulsating auroral forms, one on February 15 and the other on February 23. The nature of the field operations and some results obtained are summarized.
Correlations between the very low frequency chorus and pulsating aurora observed by low-light-level television at
Authors: Tsuruda K. , Machida S. , Oguti T. , Kokubun S. , Hayashi K. , Kitamura T. , Saka O. , Watanabe T.
Published: April 2011

A good correlation was found between the very low frequency chorus and pulsating aurora observed at Park Site (L ~ 4.4), Saskatchewan, Canada, during the recovery phase of a substorm on January 28, 1980. The activity of the chorus was low during the periods when the pulsating aurora was active over the station. However, seven chorus events were identified during that period and six of them showed one-to-one correlation with the brightening of a pulsating patch. The brightening of the patch leads chorus events by ~0.1–0.2 s. The corresponding patch detected by a low-light-level TV camera has an oval shape 75 km in the north–south direction and 150 km in the east–west direction at the ionospheric altitudes. The energy of precipitated electrons was inferred to lie between 20 and 90 keV.
Ionosonde observations of pulsating auroras
Authors: MacDougall J. W. , Koehler J. A. , Hofstee J. , McEwen D. J.
Published: April 2011

An "Australian" type ionosonde with modifications to record virtual height versus time in addition to regular ionograms was used for 23 nights during the "pulsating aurora campaign". Height variations associated with pulsating auroras were noted on 14 nights. For the periods of two rocket firings during the campaign it was possible to reproduce the height variations using modeling techniques. From the ionosonde data, information about the auroral energies and fluxes, as well as total electron content and conductivity variation, was obtained.
An auroral torch structure as an activity center of pulsating auroras
Authors: Oguti T. , Kokubun S. , Hayashi K. , Tsuruda K. , Machida S. , Kitamura T. , Saka O. , Watanabe T.
Published: April 2011

Structures of pulsating auroras were examined on three examples that occurred during a period with Kp = 6- over Park Site, and during periods with Kp = 3- and Kp = 20, over La Ronge. It was found that the fundamental structure of the pulsating aurora remains unaltered in spite of the deformation of the whole system from zonal structures during less active periods into torch structures during the magnetically active period; for example, the existence of pulsating–nonpulsating boundary and the specific distribution of pulsation modes with respect to geomagnetic latitude. It was also shown that the central regions of auroral torch structures are so called activity centers of pulsating auroras during magnetically active periods.
Latitudinal and temporal characteristics of pulsating auroras
Authors: Duncan C. N. , Creutzberg F. , Gattinger R. L. , Harris F. R. , Jones A. Vallance
Published: April 2011

Photometric observations of pulsating aurora were made from four locations on a magnetic meridian. These observations are used to develop a set of physical characteristics with which to test theoretical mechanisms for the production of pulsations. The period, absolute intensity, and amplitude of auroral pulsations are described for seven nights of observation and illustrate the development of pulsating aurora displays in invariant latitude and magnetic time.
Energies of precipitating electrons during pulsating aurora events derived from ionosonde observations
Authors: MacDougall J. W. , Hofstee J. , Koehler J. A.
Published: April 2011

The time-history of particle energies and fluxes associated with pulsating auroras in the morning sector is derived from ionosonde measurements. All the pulsating auroras studied showed a similar history with the pulsations occurring during a time interval of the order of an hour during which the average auroral Maxwellian characteristic energy stays relatively constant but the energy flux decreases progressively during the event. A possible explanation for this behaviour in terms of an injection of particles into a magnetospheric "bottle" near the midnight meridian and the progressive precipitation out of the bottle during the pulsating event is suggested.
TV morphology of some episodes of pulsating auroras
Authors: Jones A. Vallance , Gattinger R. L.
Published: April 2011

Sets of all-sky TV images of pulsating auroras obtained during the displays through which the sounding rockets of the Pulsating Aurora Campaign were fired are presented and discussed. It is emphasized that these displays are considerably more complex and variable than might seem to be the case on the basis of zenith photometer records. The pulsation modulation pattern was observed to be travelling westward during the first flight; later in the same display this apparent motion ceased. For the second flight the pulsation modulation pattern was almost stationary.
Plasma measurements in pulsating auroras
Authors: McNamara A. G.
Published: April 2011

Plasma probe experiments consisting of a Langmuir probe and a hemispherical gridded analyzer were flown on each of two Black Brant rockets during the pulsating aurora campaign in Canada in February, 1980. Electron temperature, suprathermal electron flux, and electron density profiles were obtained up to altitudes of approximately 150 km. The peak electron densities at 120 km of about 2 × 105 cm−3 are consistent with primary particle fluxes having Maxwellian distributions with a characteristic energy of about 2 keV. The integral flux of secondary electrons, with energies greater than 4 eV, increased with altitude and reached fluxes of 3.0 × 107 and 1.7 × 109 cm−2 s−1 sr−1 on the two flights. A close correlation was found between the optical pulsations and pulsations in the suprathermal flux which were 3 times the background flux. Pulsations in the electron density were barely detectable (< 20%) on only one flight. The observations support a magnetospheric flux limiting mechanism for these pulsating auroras rather than an ionospheric feedback model.
The influence of aurora on ionospheric electron content
Authors: Forsyth P. A. , Fulford J. A. , Hofstee J. , Lyon G. F.
Published: April 2011

The ionospheric electron content was measured at La Ronge, Sask. for a variety of auroral conditions during the Pulsating Aurora Campaign in February of 1980. The two-frequency differential phase technique was used with the NNSS satellite beacons. Comparisons of optical data and the radio results indicate that for quite strong pulsations the electron content is modulated by less than 2%. Even this small change is somewhat larger than the purely temporal variations to be expected on the basis of currently accepted relaxation times in the ionosphere. If the observed fluctuations are interpreted as representing both temporal and spatial variations, good agreement is obtained with model calculations. For irregularity sizes and strengths to which the experiment is sensitive, structure was present in diffuse or patchy aurora but absent from at least some well defined forms. This suggests that the technique can be used to explore the mechanism of formation of the irregularities.
Auroral electron energies: comparisons of in situ measurements with spectroscopically inferred energies
Authors: McEwen D. J. , Duncan C. N. , Montalbetti R.
Published: April 2011

Auroral electron characteristic energies determined from ground-based photometer measurements of the ratio of 5577 Å OI and 4278 Å N2+ emissions are compared with electron energies measured during two rocket flights into pulsating aurora. Electron spectra with Maxwellian energy distributions were observed in both flights with an increase in characteristic energy during each pulsation. During the first flight on February 15, 1980 values of E0 ranging from 1.4 keV at pulsation minima to 1.8 keV at pulsation maxima were inferred from the 5577/4278 ratios, in good agreement with rocket measurements. During the second flight on February 23, 1980 direct electron energy measurements yielded E0 values of 1.8 keV rising to 2.1 keV at pulsation maxima. The photometeric ratio measurements in this case gave inferred E0 values about 0.5 keV lower. This apparent discrepancy is considered due to cloud cover which impaired the absolute emission intensity measurements. It is concluded that the 5577/4278 ratio does yield a meaningful measure of the characteristic energy of incoming electrons. This ratio technique when added to the more sensitive 6300/4278 ratio technique usable in stable auroras can now provide more complete monitoring of electron influx characteristics.
Latitudinally propagating on–off switching aurorae and associated geomagnetic pulsations: A case study of an event of February 20, 1980
Authors: Oguti T. , Kokubun S. , Hayashi K. , Tsuruda K. , Machida S. , Kitamura T. , Saka O. , Watanabe T.
Published: April 2011

Poleward propagating on–off switching aurorae and equatorward propagating aurorae, otherwise similar, were observed simultaneously at Rabbit Lake and La Ronge, respectively, for about 40 min before dawn of Feb. 20, 1980. Rabbit Lake is a high auroral latitude site, at the northern end of the Saskatchewan chain of stations for the Pulsating Aurora Campaign, whereas La Ronge, due south of Rabbit, is almost at the southern edge of the auroral zone. The repetition periods of the on–off switching aurorae are about 6 to 13 s. The poleward propagating aurorae had well defined fronts of light which extended a few hundred kilometres or more in the east–west direction. The light fronts of the equatorward propagating aurorae, though comparable in extent, were less well defined: they were thicker and fuzzier. The poleward propagating aurorae moved with a speed ~10 km/s whereas the equatorward ones did so with a slightly greater velocity. Geomagnetic field fluctuations were concurrent with the aurorae at both sites. At Rabbit Lake, northward (southward) field changes were associated with upward (downward) changes whereas the trend is reversed at La Ronge, viz., northward (southward) changes with downward (upward) changes. These trends are consistent with a model of a periodic occurrence of two line currents, westward and eastward, the former moving poleward north of Rabbit Lake and the latter approaching La Ronge from the north.
Satellite observations of spatial and temporal fluctuations in post-midnight auroras
Authors: Anger C. D. , Murphree J. S. , Cogger L. L.
Published: April 2011

ISIS 2 satellite observations of the equatorward boundary of the diffuse aurora in the early morning magnetic local time (MLT) sector reveal irregularities in that boundary which are identified as a pulsating aurora. In the case of "cartwheel" data, repeated scans made through the same meridian reveal clear temporal variations in regions having scale sizes on the order of 300–400 km in north–south extent and intensities up to 60% of the diffuse auroral intensity poleward of the pulsations. When the pulsations are observed there are no corresponding fluctuations in intensity at the poleward boundary.When two-dimensional scans of the morning section are carried out, similar irregularities can be seen which range from quasi-periodic (in MLT) patch-like regions at the equatorward boundary, to north–south elongated irregularities in the diffuse aurora as a whole. Abrupt longitudinal boundaries in the irregularity regions can be seen particularly toward later MLT, suggesting that purely statistical analyses of latitude and local time distributions may not do justice to the phenomena involved.It seems quite likely that these irregularities indicate regions of pulsating auroras, in which case the pulsation regions are associated with remarkably orderly large scale fluctuations in the plasma sheet and thus may need to be viewed as something more than an irregular phenomenon governed entirely by local instabilities.
Rotational temperature variations in pulsating auroras
Authors: Koehler R. A. , Shepherd M. M. , Shepherd G. G. , Paulson K. V.
Published: April 2011

A ground-based, two channel photometer was used to derive rotational temperatures for the 4278 Å band of N2+ during the 1980 Canadian pulsating aurora campaign. Characteristic electron energies of a Maxwellian energy distribution were inferred from the rotational temperatures using computer modelling techniques. Height and electron energy fluctuations, calculated for a pulsating auroral event on February 15, 1980, are compared with ground-based ionosonde and in situ rocket measurements. The results indicate the potential of conducting electron energy morphological studies from the ground. Systematic rotational temperature variations were found to accompany each of the well-defined pulsations studied.
Photolytic effects of solar radiation at stratospheric levels during sunrise and sunset
Authors: Zucconi J.-M. , Moreels G. , Parisot J.-P.
Published: April 2011

The different terms of the photochemical mechanisms involved in the ozone steady state at upper stratospheric levels have been computed and followed as a function of time during twilight. The photodissociation coefficients have been calculated as functions of [Formula: see text] and [Formula: see text] which represent the column densities of oxygen and ozone above a given level. Chlorine chemistry has not been considered. It is shown that, at 45 km, the ozone behavior during twilight is governed mainly by photochemical processes. Under "usual conditions" defined by a night-time NO2 density of 6 × 108 cm−3, the ozone decreases by approximately 1%. Under "high NO2 conditions" defined by a night-time NO2 density of 3 × 1010 cm−3, the ozone decreases by several percent. Due to its action upon the kinetic rate constants, an increase of the atmospheric temperature emphasizes this decrease.The calculated ozone variations are compared with measurements by different experimenters using various methods. The increase during morning twilight measured by one of them cannot be reproduced with the model developed hereafter. The decrease measured by the others shortly before sunrise is more important than is calculated in the present work.
Ionospheric electron content measurements during "Waterhole"
Authors: MacDougall J. W. , Fulford J. A. , Forsyth P. A.
Published: April 2011

The "Waterhole" experiment is described elsewhere by Whalen et al. This paper describes the somewhat surprising results obtained from the differential phase measurements made during the experiment. While there is evidence that the electron concentration in the immediate neighborhood of the explosion dropped as expected, the more dramatic outcome was the sudden cessation of particle precipitation. The radio measurements show that the electron concentration in the E-region below the "hole" began to decay at the time of the explosion with a rate which is consistent with recombination. It continued to decay over the time that it could be observed, about 2.5 min. It must be concluded that the particle precipitation along magnetic field lines through the hole was cut off for at least that length of time.
Preliminary results from Project Waterhole — an auroral modification experiment
Authors: Whalen B. A. , Yau A. W. , Creutzberg F. , Gattinger R. L. , Harris F. R. , Jones A. Vallance , McNamara A. G. , Pongratz M. B. , Smith G. M. , Forsyth P. A. , Koehler J. A.
Published: April 2011

A sounding rocket carrying 100 kg of high explosives and plasma diagnostic instrumentation was launched from Churchill Research Range on 6 April 1980 over a premidnight auroral arc. The object of the experiment was to produce an ionospheric hole or plasma density depletion near 300 km altitude on field lines connected to an auroral arc. The plasma depletion is produced when the explosive by-products (mostly water) charge-exchange with the ambient O+ ions and then rapidly recombine. It was speculated that the presence of the "hole" would interfere with the field aligned current systems associated with the arc and would in turn perturb the auroral source mechanism. The release occurred about 10 km poleward of the auroral arc fieldlines. As expected, a large ionospheric hole was detected by the rocket-borne plasma sensors. Within a few seconds following the release (a) the energetic electron precipitation observed in the hole dropped to background levels, (b) the luminosity of the auroral arc observed by a ground-based auroral scanning photometer decreased by a factor of two, and (c) the ionospheric E region density below the hole decayed at a rate consistent with a sudden reduction in particle precipitation. The simultaneous onset of these gross changes in electron precipitation coincident with the release strongly suggests a cause and effect relationship and demonstrates the intimate relationship that exists between the state of the ionospheric plasma and the auroral acceleration mechanism.
Lower bound approximation to the free energy of an Ising model on a simple cubic lattice
Authors: Hu Chin-Kun , Chen Wen-Den , Shih Yu-Ming , Jou Dong-Chung , Pan C. K. , Huang H. M. , Chen Kuo-Gen , Lee W. S. , Wan D. S. , Tseng Hsien-Che
Published: April 2011

We apply a modified Kadanoff's variational method to calculate the lower bound zero-field free energies and their derivatives for an Ising model on the simple cubic lattice. We find a critical point at Kc = 0.2393769 with precision ±10−7.
Temporal and latitudinal 5577 Å airglow variations
Authors: Cogger L. L. , Elphinstone R. D. , Murphree J. S.
Published: April 2011

From 32 000 [O1] 5577 Å airglow limb observations made between April 1971 and December 1972 from the ISIS-2 satellite, the major temporal and spatial night airglow features have been identified. Two methods of analysis were employed: harmonic fitting and global correlation. Airglow emission rate maxima occurred in mid-October and mid-April at all latitudes. The intensities peaked near 35° in the winter and near 25° in the summer and showed a symmetry with latitude centred about 5° in the winter hemisphere. The mean intensity at mid-latitudes was 175 R and near the equator was 120 R. From the global correlation analysis it was shown that there are two distinct contributions to the temporal and spatial airglow variations: one is from local production which dominates during the post-solstice period, and the other is from large scale meridional transport which dominates during the post-equinox period.
Determination of dipole and quadrupole hyperfine structure in the excited B2Σ state of Ca79Br and Ca81Br
Authors: Childs W. J. , Cok David R. , Goodman L. S.
Published: April 2011

Recent molecular-beam, laser-rf, double-resonance measurements of the hfs intervals in the X2Σ ground state of CaBr have been supplemented with laser scans of the hfs of sub-Doppler B ↔ X optical lines in a molecular beam to provide greatly improved values for the hfs constants of the excited B2Σ state. The values b = 11.8 ± 0.4 MHz and eqQ = 30.4 ± 1.0 MHz are reported for the hyperfine constants of Ca79Br in its B2Σ2, ν′ = 0 state; c is found to have a magnitude not more than about 10 MHz, and may be negative.
Infrared spectrum of the fundamental ν1 of deutero-isocyanic acid
Authors: Steiner D. A. , Polo S. R. , McCubbin Jr. T. K. , Wishah K. A.
Published: April 2011

The ν1 fundamental band of DNCO has been observed for the first time under high resolution. The band origin for this deuterium–nitrogen stretching vibration is found to be at 2637.198 cm−1, rather distant from the previously reported value of 2634.9 cm−1. Eighteen subbands have been analyzed and term values for both ground and ν1 states with K up to 6 have been obtained. Effective rotational constants Bν and centrifugal distortion constants Dν and Hν have also been determined. Interaction is observed with the 2ν3 vibration which has a band origin around 2640 cm−1. Interesting perturbations are observed for the K = 0 and K = 4 levels of ν1.
Comments on tensor analysis in generalized spacetimes
Authors: Mann R. B.
Published: April 2011

The unique relationship between covariant and contravariant tensors that exists in general relativity no longer exists in generalized spacetimes with nonsymmetric metrics. The nature of covariant and contravariant tensors and their relationships in such spacetimes is clarified. An example is given to show that sensible field equations may be derived from a Lagrangian for such spacetimes, and that these equations differ nontrivially from general relativity. The physical applications of such a formalism are discussed.