bluuebunny/crossref_metadata_2025 huggingface dataset:
Sea level muon spectrum from pion and kaon spectra in the atmosphere
Authors: Bhattacharyya Deba Prasad
Published: April 2011

The pion and kaon spectra in the top of the atmosphere have been derived from the satellite data of cosmic ray nucleons by using the Bose-type distribution of secondary mesons produced in the inclusive reactions p + p → π− + X and p + p → K− + X. The derived pion and kaon spectra follow the relations of the form π(Eπ) dEπ = 0.184Eπ−2.6 dEπ and K(Ek) dEk = 0.036 Ek−2.6 dEk. With the help of the diffusion equation for pions and kaons in the atmosphere, the sea level muon spectrum has been derived and the results have been compared with the magnetic spectrograph data of Allkofer, Carstensen, and Dau in the muon momentum range 15–1000 GeV/c. The sea level muon intensity arising from kaon parentage increases with energy.
Quasistatic transient electromagnetic response of a permeable nonuniformly conducting cylinder
Authors: Verma S. K. , Joshi M. S.
Published: April 2011

The step-pulse response of a permeable and a radially nonuniformly conducting cylinder is obtained. Effects of the conductivity distribution pattern and the magnetic permeability on the transient response are examined in detail. It is found that: (i) the initial response (for t → 0) remains unaffected by both the inhomogeneity and the permeability of the cylinder; (ii) the large time response is governed only by the permeability; and (iii) the conductivity inhomogeneity is reflected only during intermediate times. Finally, the implications of the results for predicting the parameters of the cylinder are discussed.
MHD simulation of a beat frequency heated plasma
Authors: Milroy R. D. , Capjack C. E. , James C. R. , McMullin J. N.
Published: April 2011

The heating of a plasma in a solenoid, with a beat frequency harmonic which is excited at a frequency near to that of a Langmuir mode in a plasma, is examined. It is shown that at high temperatures the heating rate is very insensitive to changes in plasma density. The amount of energy that can be coupled to a plasma in a solenoid with this heating scheme is investigated by using a one-dimensional computer code which incorporates an exact solution of the relevant MHD equations. The absorption of energy from a high powered laser is shown to be significantly enhanced with this process.
A new determination of the parameters of the optimized Heine–Abarenkov potential for 27 elements
Authors: Cowley E. R.
Published: April 2011

We have calculated the energy levels of the truncated Coulomb potential using numerical integration of the radial Schrödinger equation, rather than interpolation in tables. The results are used to give the parameters of the optimized Heine–Abarenkov potential for 27 elements. Various methods of weighting other contributions to the potential in the solid are used, and the inhomogeneity correction introduced by Ballentine and Gupta is discussed.
Les états électroniques de la molécule LuF
Authors: Effantin C. , Wannous G. , d'Incan J.
Published: April 2011

About 150 bands belonging to the spectrum of the LuF molecule are classified into 8 electronic systems lying between 3000 and 6500 Å; the results are in good agreement with those deduced from a previous rotational analysis of 20 bands.
Electromigration in Al thin films
Authors: Pai S. T. , Marton J. P. , Beatty D. C.
Published: April 2011

Al films were subjected to DC and AC currents at various current densities in high and low ambient temperatures to cause migration in the films. The results were compared with the predictions of Pai and Marton regarding the direction of migration, its reversal near the melting point, the position and time dependence of migration, and other features. The agreement between theory and experiment was found reasonable, and the numerical values of migration and material constants obtained from the analysis were consistent. The work shows that a quantitative analysis of electromigration data is possible and the results are valuable.
Time resolved X-ray photography of a dense plasma focus
Authors: Burnett J. C. , Meyer J. , Rankin G.
Published: April 2011

The temporal development of the hot plasma in a dense plasma focus is studied by X-ray streak photography of ~2 ns resolution time. It is shown that initially a uniform X-ray emitting pinch plasma is formed which subsequently cools down until X-ray emission stops after ~50 ns. At a time of around 100 ns after initial X-ray emission coinciding with the break-up time of the pinch a second burst of X-rays is observed coming from small localized regions. The observations are compared with results obtained from time-resolved shadow and schlieren photography of a similar dense focus discharge (Peacock, Hobby, and Morgan).
Gamma decay of the T = 3/2 states in 25Al
Authors: Rogers D. W. O. , Anyas-Weiss N. , Dolan S. P. , Jelley N. A. , Alexander T. K.
Published: April 2011

The decay of the two lowest T = 3/2 levels at Ex = 7901 ± 2 and 7969 ± 2 keV in 25Al have been investigated using the 24Mg(p,γ)25Al reaction. Angular distribution and radiative yield measurements rigorously assign J = 5/2 to the lower level. J = 3/2 is consistent with the results for the upper level although J = 5/2 and 7/2 are also admissible. Any possibility of an inversion of these states as compared to the first two levels in 25Na is excluded by these results. The measured radiative yields are ωγ = 0.25 ± 0.06 and 0.40 ± 0.09 eV for the lower and upper resonances respectively. Two previously reported γ-decay branches from the upper resonance were found to be nonresonant. Comparisons to recent shell model calculations show poor agreement.
Positron annihilation in methane
Authors: Mao A. C. , Paul D. A. L.
Published: April 2011

Measurements of positron annihilation rates at room temperature under the influence of an applied electric field have been made in methane at different pressures. The experiments were all carried out in the linear region in which the annihilation rate is accurately proportional to gas density. We find Zeff = 142.7 ± 2.0 at 21 °C and zero electric field. At 1000 Torr Zeff decreases linearly with the electric field, the gradient being about 2.5 × 10−2 per (V cm−1 atm−1) at that temperature. The results repudiate the idea of a positive energy single level Breit–Wigner resonance as being responsible for the high value of Zeff, and in this sense are in agreement with the findings of McNutt, Summerour, Ray, and Huang.
Electronic spectra of metal ion – rare gas pairs: High resolution analysis of the A2Πr–X2Σ+ system of BeKr+
Authors: Coxon J. A. , Jones W. E. , Subbaram K. V.
Published: April 2011

The A2Πr–X2Σ+ system of Be84Kr+ has been studied at high resolution in the region 3950–4265 Å. Rotational analyses have been performed for the 0–1, 0–0, 1–0, and 2–0 bands, and molecular constants have been determined by least squares fits of the line frequencies to model Hamiltonians. The regular nature of the excited state has been confirmed, despite the opposite signs found for the Λ-doubling constants, p and q. Comparisons of the Λ-doubling constants for the A2Πr state and of the spin-splitting constant (γ) for the X2Σ+ state have been made with those for other nine valence-electron diatomics. Although a systematic study of isotope effects due to the several isotopes of naturally-occurring krypton has not been possible, at least one branch of the 1–0 band of Be86Kr+ has been identified unequivocally.
The atomic bound state of two pions and the π π scattering lengths
Authors: Maltman Kim , Vogt E. W.
Published: April 2011

An upper bound for the low energy production rate of π+ π− atomic bound states in NN collisions is obtained and used to investigate the feasibility of taking π π scattering lengths from the X rays of this system.
Cooperative Thomson scattering from plasma with pulsed CO2 laser radiation
Authors: Pasternak A. W. , Offenberger A. A.
Published: April 2011

An experiment is described in which a 10–20 MW pulsed CO2 laser is used to probe the thermal ion fluctuations in a magnetized argon arc plasma with [Formula: see text], [Formula: see text], and [Formula: see text]. Resolution of scattered ion spectra is achieved with a high finesse infrared Fabry–Perot interferometer. Scattered information is recovered through a multi-shot signal averaging technique which yields a S/N factor of ~ 10 for < μW scattered power levels. Results are compared with spectra calculated from a knowledge of plasma conditions and laser and instrumental linewidths. Demonstration of this diagnostic technique indicates that similar methods could be successfully applied to present magnetically confined fusion research plasmas.
The radial density function for the neutral atoms from helium to xenon
Authors: Boyd Russell J.
Published: April 2011

Analytical expansions for the radial density D(r), as calculated within the Hartree–Fock approximation, are reported for the neutral atoms from helium to xenon. As part of a brief discussion of one-electron properties which may be calculated from D(r) or the related density distribution ρ(r), expectation values for rn, n = −2, −1, 1, 2, 3, 4, and 5 are presented.
The nuclear magnetic field, Cabibbo angle, and CP violation in the nucleus
Authors: Lee H. C. , Khanna F. C.
Published: April 2011

The magnetic field in the nucleus is calculated microscopically. It is deduced that Salam and Strathdee's theory will unlikely provide an explanation for anomalies in the Fermi coupling constants in 35Arand 93Nb. CP violation in the β-decays of n and 19Neis not ruled out.
4d9 → 4d85p transitions in Cd IV, Sn VI, and Sb VII and the resonance lines of Sn V and Sb VI
Authors: Joshi Y. N. , Van Kleef Th. A. M.
Published: April 2011

The spectra of cadmium, tin, and antimony have been photographed in the region 600–200 Å on 10.7 and 6.6 m grazing incidence vacuum spectrographs using a triggered spark and a sliding spark as light sources. The analyses of the 4d85p configurations in Cd IV and Sn VI have been revised and extended. The parametric level fitting calculations and relative oscillator strengths calculations of the allowed transitions confirm the present analyses. The separation of the 4d92D multiplet in Sb VII has been determined; its value is 10 405 ± 2 cm−1. Accurate measurements of the resonance lines of Sn V and Sb VI have resulted in raising every level of Sn V by +415 cm−1 and of Sb VI by +5 cm−1.
fluorescence from Penning excitation of SO2
Authors: Wu Konrad T. , Yencha Andrew J.
Published: April 2011

[Formula: see text] fluorescence emission was observed and analyzed in the 300–550 nm spectral range from a flowing afterglow study of the reaction He(23S) + SO2. The band system, which has its origin at 333.9 nm, is characterized by a long progression of symmetrical stretching vibrations (ν1′, 0, 0) → (ν1″, 0, 0) for 0 ≤ ν1″ ≤ 2 with [Formula: see text] and a number of bending modes (0, 0, 0) → (ν1″, ν2″, 0) for [Formula: see text] with 0 ≤ ν1″ ≤ 9. The symmetrical stretching vibrational frequency of the [Formula: see text] state was determined to be 1264 ± 10 cm−1 which had not been observed previously. The ν2″ bending frequency of the [Formula: see text] state of SO2+ was found to be ~404 cm−1. SO(B3Σ− → X3Σ−) and SO2(Ã1B1 → [Formula: see text]) emission is also observed in the He(23S) + SO2 reaction system, but molecular ion fluorescence is the predominant emission system. From a comparison of the emission spectrum produced by helium metastables with that produced by argon (3P2, 0) metastables, it is concluded that neutral excitation and dissociative excitation occur at large interparticle distances while Penning ionization occurs at small interparticle distances in the case of the sulfur dioxide system.
The hyperfine field at Ti nuclei in Fe and Ni and the g factor of the 160-keV 7/2− level of 47Ti
Authors: Bullimore B. , Cameron J. A.
Published: April 2011

Integral rotation of the 3/2+ 320-keV level of 45Ti and the 7/2− 160 keV level of 47Ti recoil implanted in iron and nickel were measured following (α,n) reactions in 42Ca and 44Ca on magnetized backings. The average hyperfine field at 45Ti nuclei is Hhf(TiFe) = −45 ± 10 kOe and Hhf(TiNi) = −15 ± 3kOe. The g factor of the 7/2− first excited state of 47Ti is −0.55 ± 0.17.
Apparatus for the study of the transmission of 24 GHz radiation through metal plates and for the study of FMR absorption lineshapes
Authors: Cochran J. F. , Heinrich B. , Dewar G.
Published: April 2011

A description is presented of a 24 GHz microwave transmission apparatus having a sensitivity of approximately 10−17W in a 10 Hz bandwidth, and of a novel bolometric method for the measurement of ferromagnetic resonance lineshapes in metals. The role played by the cavity modes in transmission and absorption measurements is discussed. In addition, we have discussed the measurement of the effective dc field in disc-shaped ferromagnetic samples and the measurement of the microwave frequency.
Earth albedo effects in satellite auroral photometry
Authors: Harrison A. W. , Anger C. D.
Published: April 2011

ISIS 2 satellite photometer scans have been analyzed to obtain the integrated photon flux (3914 Å) from a thin slice of the auroral oval viewed during one spin of the spacecraft. The results have been corrected for earth surface albedo contamination and shown to be consistent with model calculations. An empirical equation has been developed which permits estimation of the integrated photon fluxes directly from observed scan profiles provided that the spectral albedo is known. The technique should make it possible to estimate the instantaneous total global deposition of particle energy into the auroral zone ionosphere.
Extension of high resolution beam maser spectroscopy into the submillimetre wave region
Authors: Garvey R. Michael , Lucia Frank C. De
Published: April 2011

High resolution molecular beam maser spectroscopy has been extended into the submillimetre wave region of the spectrum. The maser spectrometer consists of a multiple beam source, stacked quadrupole state selector, and Fabry–Perot cavity. The submillimetre wave stimulating signal is produced by harmonic generation from a millimetre-wave klystron, directly referenced to WWVB. The maser signal is detected in a cryogenic photodetector. Linewidths 50–100 times narrower than the Doppler width and good signal-to-noise ratios were obtained. This system has been used to resolve the small deuterium hyperfine splittings of both the 110 → 101 transition of D2O at 317 GHz and the J = 1 → 0 transition of ND3 at 309 GHz. The relevance of the D2O quadrupole interaction data to the electric field gradient in water is discussed. The spectroscopic constants in kilohertz for D2O in the states 110 and 101 are, respectively, (eQqJ)D = 34.81 ± 0.32, CD = −2.661, and (eQqJ)D = −29.60 ± 0.55, CD = −2.532. The constants for ND3 are, in kilohertz: (eQqJ)N = 816.2 ± 1.1, CN = 2.0 ± 1.5, (eQqJ)D = 19.9 ± 0.8, and CD = −2.2 ± 0.8.
Microwave spectrum, dipole moment, and centrifugal distortion constants of 1,2,3,5-tetrafluorobenzene
Authors: Sharma S. D. , Doraiswamy S.
Published: April 2011

The microwave spectrum of 1,2,3,5-tetrafluorobenzene has been studied at dry ice temperature in the frequency region of 8 to 12.4 GHz. The molecule is highly asymmetric (κ = 0.001129) and exhibits an a-type spectrum. The analysis of the spectrum has been carried out to obtain the following Watson's eight determinable parameters: [Formula: see text], [Formula: see text], [Formula: see text], τ′aaaa = −1.30 ± 1.26 kHz, τ′bbbb = −4.05 ± 0.40 kHz, τ′cccc = −0.75 ± 0.40 kHz, τ1 = −15.21 ± 1.34 kHz and [Formula: see text]. The dipole moment of the molecule is found to be 1.46 ± 0.06 D. The calculated values obtained from INDO and CNDO approximations are 1.73 and 1.64 D, respectively. The benzene ring appears to have undergone a distortion if we assume that C(sp2)—F bond length is around 135 pm.
Many body theory of resonant dielectric susceptibility in a gas
Authors: Zaidi H.R.
Published: April 2011

A theory is developed for the resonant dielectric susceptibility of a high density gas which consists of two level atoms interacting through the dipole–dipole potential. A many body collision model, which includes the binary as well as the shielding effects, is investigated. The linear response of the dielectric is given by a generalized transport equation. Self-consistent coupled equations are derived for the various collision operators, using the propagator techniques. In the two limiting cases, the results of the binary collision model and those of the shielded interaction model, respectively, are recovered. The equations are simplified by neglecting the nonresonant contributions. Finally, a solution is obtained in the resonance broadening approximation. The resulting expression for the dielectric susceptibility includes the two body collision as well as the many body shielding effects. In particular, it includes the important collective excitation transfer effects. The proposed many body collision model should be appropriate for the resonant, linear response of high density gases.
New lines in the L-spectrum of neodymium-60
Authors: Shrivastava B. D. , Jain R. K. , Dubey V. S.
Published: April 2011

Using a focusing X-ray spectrograph of Cauchois type, three new lines at 1737.2, 2280.9, and 2354.9 X unit (Xu) have been observed in the L-emission spectrum of neodymium-60. The first two lines have been ascribed to the forbidden transition LI,NVI, VII and quadrupole transition LIIMIII (β17), respectively. The third one has been identified as the high frequency satellite Lαx. The existence of three quadrupole lines LINIV, V (γII), LIINVI, VII (γ8′), and LIIINVI, VII (β7′), only reported by Gokhale and Shukla, has been confirmed. The measurements of previously known diagram lines have been compared with those of earlier workers.
Infrared saturable absorbers. Part II: Intensity dependent transmission of SF6 at 936.8 wave numbers
Authors: Caudle George F. , Izatt Jerald R. , Lim Tuan-Kay
Published: April 2011

Due to rotational hole burning Q-switched laser pulses sometimes saturate a molecular absorber more effectively than CW laser radiation. The absorption by SF6 of frequencies near the P(28) line in the 10.6 μm CO2 laser band provides an interesting example. In this case it has been reported elsewhere that for peak intensities [Formula: see text] an increase in pulse intensity produces a monotonic increase in transmission whereas the CW transmission decreases monotonically with intensity. We report new measurements made over a wider range of laser power levels and at several SF6 pressures, which show that the global behavior of the transmission as a function of average beam power is quite similar for both CW and pulsed radiation. The pulse transmission is somewhat greater at all power levels, but when the average power is sufficiently high the growth of hot-band absorption and possibly other intensity dependent changes in the ground and excited-state absorption cross sections cause the transmission to fall well below its low-intensity value for CW radiation and pulses alike. The experimental transmission curves for both cases display as many as three extrema and cannot be explained, even qualitatively, by the five-level model used in the earlier work. The extended results are consistent with the modified five-level model presented in Part I of this pair of papers.
Extracting radiative decay widths from the reaction π−p → ηγn
Authors: Kung Chi-kwong , Isgur Nathan
Published: April 2011

We give d2σ/dt dm2 for the reaction π−p → ηγn in a form suitable for the extraction of the interesting radiative widths ρ → ηγ and ω → ηγ and the relative phase of the ρ and ω decay amplitudes.
The influence of cylindrical absorbing channels on a tilted neutron flux distribution
Authors: Love M. D. , Kushneriuk S. A.
Published: April 2011

Formulae are presented for determining the response coefficient (the 'dipole' coefficient) of the asymptotic neutron flux distribution in the medium surrounding a neutron absorbing rod when, in the absence of the rod, the flux in the medium is of linear form. The formulae are based on a variational approximation for the coefficient. The medium surrounding the rod is assumed to be isotropically neutron scattering and non-absorbing. The rod may be composite in form; a homogeneous, purely neutron-absorbing inner region surrounded by a uniform, weakly neutron-absorbing sheath or an air-gap or both. The one-velocity approximation is made. The rod is of infinite height and the neutron sources are at infinity.
The transmitted field of a Gaussian laser beam at total internal reflection
Authors: Antar Yahia M. M.
Published: April 2011

The transmitted field in the rarer medium, due to a Gaussian beam that is incident, at a planar interface separating two lossless dielectric media, at or beyond the critical angle, is considered. The beam is analysed in terms of an integral representation of continuous plane wave spectra, and the analytic solution that completely describes the transmitted field is obtained. The field features in the rarer medium, with its different wave species, are thoroughly and carefully examined. Particular emphasis is given to the field properties in the near range, diffraction effects or lateral wave field, and the field penetration in the rarer media. While the obtained results are in agreement with previous predictions, they are, as expected, in contradiction with geometrical optics predictions.
Mechanical forces in a dielectric due to electromagnetic fields
Authors: Walker G. B. , Walker G.
Published: April 2011

Experimental evidence is obtained indicating a mechanical force in a dielectric subjected to crossed electric and magnetic fields consistent with the predictions of the Abraham energy momentum tensor. In the course of the experiment a most unusual force was observed, which appeared as a surface drag on a thin metal coating applied to the dielectric. It is suggested that the force was due to the action of a tangential electric field component acting on the induced surface charge of the metal coating.
The 13C(d,γ0)15N reaction around Eexc = 17.7 MeV
Authors: Bianco W. Del , Marquardt N. , Farzine K. , Buttlar H. V.
Published: April 2011

The 95° differential cross section of the 13C(d,γ0)15N reaction has been measured at deuteron energies from 1.1 to 4.2 MeV. The γ rays have been detected by a 25.4 cm long by 25.4 cm diameter NaI(Tl) crystal spectrometer. The yield curve reveals a single resonance structure at Ed = 1.74 ± 0.04 MeV (Eexc = 17.7 MeV).
CO laser gain measurements in acetylene oxygen detonation products
Authors: Armstrong Bruce A. , Ahlborn Boye , Mikoshiba Shigeo , Tulip John
Published: April 2011

We have observed gain for CO laser transitions in the reaction products of an acetylene oxygen detonation after expanding the hot gas by means of a supersonic nozzle.
Grüneisen parameters of noble metals
Authors: Prasad B. , Srivastava R. S.
Published: April 2011

The Grüneisen parameter has been calculated for different values of the phonon wave vector in the three principal symmetry directions [100], [110], and [111] for noble metals Cu, Ag, and Au using an approach put forward by Toya. The average value of the Grüneisen parameter γM has also been calculated for different temperatures and the results are compared with the experimentally measured values.
On the electronic specific heat in dilute alloys
Authors: Larose L. , Kus F. W. , Carbotte J. P.
Published: April 2011

The coefficient γ of the electronic specific heat is calculated accounting, on the same footing, for the change in the band density of states and the change in the electron–phonon mass renormalization that occurs when small amounts of impurities are added to a pure metal. For alkali alloys it is found that the changes in the mass renormalization are more important than density of state changes.
Neutron scattering from nonsuperfluid 4He
Authors: Woods A. D. B. , Svensson E. C. , Martel P.
Published: April 2011

Tables of values of the resolution-broadened dynamic structure factor, SR(Q,v), for liquid 4He at 4.2 K and saturated vapor pressure are presented. The results are discussed in terms of several models. No existing model is able to give an adequate description over the entire range covered by the measurements, 1.0 ≤ Q ≤ 100 nm−1.
The configuration of a polymer chain interacting with a plane interface
Authors: Lépine Yves , Caillé Alain
Published: April 2011

The interaction between a linear polymer and an interface is studied for three types of surfaces: reflective, attractive, and repulsive. The freely jointed chain model is assumed in the equation of diffusion approach, with volume exclusion effects neglected. In this case, the distribution function of the polymer is derived with the assumption that one or both ends of the polymer are bound to the interface. We evaluate the mean thickness of the polymer layer, the average number of adsorbed monomers, and the mean distance of the monomers from the surface. When one end of the polymer is bound to the interface, the results are qualitatively compatible with those of the previous lattice models. When both ends are bound, the polymer stays nearer to the interface but the macroscopic mean values stay qualitatively the same.
Magnon drag and the low temperature thermopower of GeMnTe
Authors: Cafaro A. , Hedgcock F. T. , Muir W. B.
Published: April 2011

The thermoelectric power of pure GeTe and GeMnTe containing 1 and 5at.% Mn has been measured between 25 and 2.5 K. The manganese doped Ge–Te alloys ferromagnetically order at low temperatures and theoretical estimates of the magnon drag contribution to the thermopower in these degenerate semiconductors is 60 μV/K. When appropriate allowance is made for the effects of impurity scattering on the phonon drag thermopower there appears to be no experimental evidence for a magnon drag contribution to the thermopower of this magnitude. An upper limit for the magnon drag contribution to the thermopower estimated from the experimental results for these materials is 0.5 μV/K.
Non-adiabaticity in palladium hydride and deuteride
Authors: Brown J. S.
Published: April 2011

We report the results of estimates of the breakdown of the Born–Oppenheimer approximation for the optical mode vibrations in PdHx and PdDx, using a recent formulation of the threshold for breakdown. Estimates are given of the degree of adiabaticity in these alloys as a function of the H(D) concentration x. We point out the result that for concentrations x for which the d-band has filled, the Born–Oppenheimer approximation may break down slightly, and there may be smaller corrections to static screening for lower concentrations. The estimate suggests that frequency-dependent electronic screening effects may not be totally negligible in a detailed treatment of the phonon dispersion of optical modes in these alloys, and other properties which may be affected by the electron–phonon coupling.
Raman scattering from impurities in semiconductors. II. Special cases
Authors: Barrie Robert , Chow H. -C.
Published: April 2011

Special cases of the general result for Raman scattering from an impurity in a semiconductor are discussed. For weak electron–phonon coupling the zero-phonon and one-phonon scattering intensities are derived. For strong electron–phonon coupling a comparison is made between two different approximations that have been previously used.
The decay of a four-quasiparticle isomer in 176Ta
Authors: Buja-Bijunas L. , Waddington J. C.
Published: April 2011

A four-quasiparticle isomer in 176Ta has been found which decays with T1/2 = 3.8 ± 0.4 μs. The decay proceeds to a compressed rotational band which has been tentatively assigned a Kπ = 8−, 9/2−[514)p + 7/2+[633]n configuration with a large admixture of the Kπ = 9−, 9/2−[514]p + 9/2+[624]n configuration. This band decays, in turn, to the Kπ = 7+, 9/2−[514]p + 5/2−[512]n bandhead. The isomer probably has Iπ = 13− and two possible configurations for its structure have been suggested.
Sensitized fluorescence in thallium induced in collisions with Hg(63P1) atoms
Authors: Wade M. K. , Czajkowski M. , Krause L.
Published: April 2011

The transfer of excitation from excited mercury atoms to ground-state thallium atoms was investigated using techniques of sensitized fluorescence. A Hg–Tl vapor mixture contained in a quartz cell was irradiated with Hg 2537 Å resonance radiation which caused the mercury atoms to become excited to the 63P1, state. Subsequent collisions between the Hg(63P1) and Tl(62P1/2) atoms resulted in the population of the 82S1/2, 62D, and 72S1/2 thallium states, whose decay gave rise to sensitized fluorescence of wavelengths 3231, 3520, 3776, and 5352 Å. Intensity measurements on the sensitized fluorescence and on the Hg 2537 Å resonance fluorescence, observed at right angles to the direction of excitation, yielded cross sections of 3.0, 0.3, and 0.05 Å2 for collisional excitation transfer from Hg(63P1) to the 82S1/2, 62D, and 72S1/2 states in thallium, respectively. The results are fully consistent with previously determined cross sections for excitation transfer in other binary metallic vapor systems.
Etude de quelques états excités de 28Si
Authors: Dalmas J. , Petit G. Y.
Published: April 2011

The decay of 28Si energy levels at 4.98, 6.28, 6.69, 7.42, 7.80, and 7.93 MeV excited in the 27Al(p,γ)28Si reaction has been investigated. Lifetime and branching ratio studies on 0+ and 2+ levels leads to the conclusion that the existence of an excited prolate rotational band cannot be definitely ruled out, so that both prolate and oblate intrinsic states may be present as predicted by Hartree–Fock calculations. From these calculations, two low-lying (Jπ, K) = (3+, 3) levels due to particle–hole type excitations of the oblate and prolate intrinsic states should be present: emphasis was given to measurements on levels at 6.28 and 7.80 MeV as possible candidates. The mixing ratio for the 3+ → 3+ gamma ray transition has been studied from angular distribution measurements. An E2 strength of 17 ± 6 Wu (Wu = Weiskopf unit) is proposed, which is in agreement with a strong deformation of both states, but in disagreement with an important shape difference like prolate versus oblate.
Absorption spectrum and absorption coefficients of NO2 in the vacuum ultraviolet region
Authors: Morioka Yumio , Masuko Harunobu , Nakamura Masatoshi , Sasanuma Michio , Ishiguro Eiji
Published: April 2011

The absorption coefficients of NO2 in the region from 500 to 1100 Å are measured by a photographic method using the radiation from electron synchrotron as a background source. For the Rydberg series due to the transition from 4a1 to npπ, parameters q and Γ in Mies equation are obtained and the parameter q is determined to be −0.4 for every member and Γ 4.808/n*3 eV where n* is the effective quantum number.The absorption spectrum of NO2 in the region from 600 to 1600 Å are also analyzed. New vibrational progressions that are observed around 950 Å, are assigned to the excitations from 4b2 to ns Rydberg states (n = 3, 4, and 5) converging to the 1B2 ionic state. Assignments and discussions of many other Rydberg series that appear in the absorption spectrum between 600 and 1600 Å are also presented.
Antiferromagnetism in amorphous alloys containing rare-earth atoms. I. The molecular field approximation
Authors: Ferrer R. , Zuckermann M. J.
Published: April 2011

The model of Harris, Plischke, and Zuckermann for random magnetic anisotropy in amorphous alloys is examined in the molecular field approximation for the case of antiferromagnetic exchange coupling. The existence of spin-flop transitions and a spin-glass-like magnetic susceptibility is established by numerical calculation. The results are discussed in connection with current theoretical and experimental work.
Pressure shifts in the vibrational Raman spectra of hydrogen and deuterium, 315–85 K
Authors: Looi E. C. , Stryland J. C. , Welsh H. L.
Published: April 2011

The Raman frequencies of the Q(J) lines of the fundamental Raman bands of compressed H2 and D, were measured with a standard deviation of ±0.02 cm−1 at gas densities from 10 to 100 amagat at several temperatures in the range 315 to 85 K. The frequency shifts are negative and linear in the gas density; they range up to −1.2 cm−1 for H2 and −0.7 cm−1 for D2. The linear coefficient for the Q(J) line has the form, ai + ac(nJ/n), where nJ/n is the fractional population of the rotational level, J, and ai and ac are constants independent of J. The constant ai is strongly temperature-dependent and is interpreted as the vibrational shift due to isotropic dispersion and overlap forces. On the other hand, ac is practically temperature-independent and is believed to arise from vibrational coupling through dispersion forces.
Magnetic field necessary to destroy superconductivity in Al-type Se and Te
Authors: Reale Carlo
Published: April 2011

This paper reports the results of a study of the critical magnetic field required to restore electrical resistance in superconducting metastable Al-type Se and Te overlays vapor-quenched, respectively, on MgO, FeO, CoO, or NiO and CaO or MnO base films quench-condensed on glass substrates. The critical field was measured at various temperatures, from the superconducting transition temperature in zero field down to 0.1 K, for overlay thicknesses ranging from 100 Å up to values at which size effects disappear. The measurements were repeated after cyclic annealing at increasing temperatures up to a limiting temperature at which the overlay breaks owing to the transformation of the A1-type modification to the less dense ordinary A8-type structure.The critical field decreases steeply, with increasing thickness, down to a constant bulk-material value, increases nearly parabolically, with decreasing temperature, up to an extrapolable absolute-zero value, and decreases irreversibly with increasing annealing temperature. The superconducting-to-normal phase transition occurs through an intermediate state, which indicates that quench-deposited A1-type Se and Te are soft superconductors.
Absorption spectrum of bismuth in the region 2300–1250 Å, using the flash pyrolysis technique
Authors: Joshi Y. N. , Srivastava R. P.
Published: April 2011

The absorption spectrum of bismuth was photographed in the region 2300–1250 Å on a 3-m normal incidence spectrograph. The absorption cell consisted of a flash pyrolysis system and the background continuum source was a Garton flash lamp. The spectrum has been revised and extended. The series based on 6p2(3P)ns and 6p2(3P)nd were extended to n = 20 in many cases. All the ionization limits have been reduced by 25 cm−1. Seventeen wide autoionized lines are reported. Eight Bi II lines were also observed in the absorption.
Self-coupled vector fields
Authors: McKeon Gerry
Published: April 2011

By use of Dirac's quantization procedure for constrained systems, it is possible to derive the Schwinger treatment of magnetic monopoles from a Lagrangian. A generalization of this Lagrangian leads to a self-coupled vector field. The techniques used are also applied to an extended Yang–Mills Lagrangian based on Zwanziger's local Lagrangian theory of magnetic monopoles. These systems exhibit CP violation.
A study of the electric quadrupole fundamental band of D2 using an infrared difference frequency laser system
Authors: McKellar A. R. W. , Oka T.
Published: April 2011

Frequency tunable infrared radiation from a difference frequency laser system has been used with a long path cell to study the electric quadrupole vibration–rotation spectrum of the deuterium molecule in the 2.8–3.9 μm region. A ratio method as well as frequency modulation were used to detect the weak absorption. Sub-Doppler linewidths due to collisional narrowing were observed with a D2 pressure of 1 atm. The wavelengths of 11 transitions were measured relative to infrared reference lines, and improved molecular constants for the ν = 0 and 1 states of D2 were determined.
Cumulative yields of stable and long-lived isotopes of ruthenium and palladium in neutron-induced fission
Authors: Shima Masako , Thode H. G. , Tomlinson R. H.
Published: April 2011

The relative cumulative yields of nine stable and long-lived isotopes of ruthenium and palladium (masses 101 to 110) produced in the thermal neutron fission of 233U and in the thermal and epicadmium neutron fission of 235U and 239Pu have been measured using a solid source mass spectrometer and isotope dilution techniques. Absolute yields of these isotopes for the thermal neutron fission of 233U, 235U, and 239Pu are obtained using normalization procedures. These yields provide the first experimentally determined yields of the palladium masses 105, 106, 107, 108, and 110.In the thermal fission of 233U and 235U the ruthenium isotope yields obtained are in general agreement with previously determined values, although discrepancies exist of the order of 10% at masses 103, 104, and 106 for thermal fission of 235U.A plot of the ruthenium and palladium isotope mass yields together with the previously determined yields for the cadmium and tin isotopes indicate a significant depression in the mass yield curve at masses 111 and 114 for 233U and 235U thermal fission, respectively. In the 235U epicadmium fission, yields at even mass numbers are relatively higher than those at odd numbers, resulting in a zigzag yield curve in the 101 to 110 mass region.
Specific heat of ordered and isotopically disordered lattices
Authors: Srivastava K. P.
Published: April 2011

An extensive numerical study on specific heat at constant volume (Cv) for ordered and isotopically disordered lattices has been made. Cv at various temperatures for ordered and disordered linear and two-dimensional lattices have been compared and no appreciable difference in Cv between these two structures has been observed. Effect of concentration of light atoms on Cv for three-dimensional isotopically disordered lattices has also been shown.In spite of taking next-nearest-neighbour interaction into account, no substantial change in Cv between the ordered and isotopically disordered linear lattices has been found. It is shown that the low lying modes contribute substantially at low temperatures.
8He nuclei amongst 'hammer tracks' in 1.8 GeV/c K−-meson interactions in nuclear emulsion
Authors: Mandal P. , Bhattacharya D. K. , Saha M. , Sen P. K.
Published: April 2011

Charges of 'hammer tracks' produced in the interaction of 1.8 GeV/c K−-meson in nuclear emulsion have been determined using the method of track width measurement. Approximately 14.0% of the hammer tracks are found to be due to 8He fragments.
Theory of spin waves in triangular antiferromagnets
Authors: Oyedele J. A. , Collins M. F.
Published: April 2011

A simple hexagonal array of classical spins coupled by nearest-neighbour antiferromagnetic Heisenberg interactions has a ground state with a triangular antiferromagnetic configuration of spins. We have developed spin wave theory for triangular antiferromagnets with both Heisenberg and dipole–dipole interactions. The dipole–dipole interactions confine the spins to the hexagonal basal plane and they do not distort the equiangular triangular structure. Spin wave dispersion relations are plotted for some trial values of the exchange constants. The theory is applied to the triangular antiferromagnet CsMnBr3. This is a quasi-one-dimensional material with strong exchange interactions along the hexagonal axes and with weak exchange interactions within the basal plane that are of the same order as dipolar interactions.
Elastic constants of parahydrogen determined by Brillouin scattering
Authors: Thomas P. J. , Rand S. C. , Stoicheff B. P.
Published: April 2011

Five single crystals of parahydrogen were grown near the triple point, and their Brillouin spectra examined in known crystal directions. An analysis of the measured frequency shifts of longitudinal and transverse components led to the direct determination of the adiabatic elastic constants at 13.2 K: C11 = 3.34 ± 0.05, C13 = 0.56 ± 0.03, C33 = 4.08 ± 0.06, C44 = 1.04 ± 0.03 kbar. The fifth elastic constant C12 = 1.30 ± 0.05 kbar was evaluated from the relation C11 + C12 = C13 + C33. Values of the following constants were calculated: elastic anisotropy, A = 1.02 ± 0.06, adiabatic bulk modulus, Bs = 1.73 ± 0.04 kbar, and Debye temperature, θD = 111.2 K. All of these values were compared with earlier experimental measurements. The elastic constants were found to be in good agreement with a recent self-consistent phonon calculation by Goldman.
Positron annihilation in 60Co irradiated alkali halides
Authors: Dannefaer S. , Kerr D. P. , Dean G. W. , Hogg B. G.
Published: April 2011

A systematic investigation of 17 gamma-irradiated alkali halides using positron lifetime and Doppler broadening techniques has been performed. For eight of the alkali halides (NaCl, NaBr, KCl, KBr, KI, RbCl, RbBr, and RbI), a new lifetime with values between 1.0 and 1.3 ns is attributed to positrons trapped in F centres. Despite large F centre concentrations in LiF, LiCl, LiBr, and NaF, no such lifetime component is observed in these samples. Doppler broadening measurements show that in nearly all cases the momentum distribution becomes narrower upon irradiation. The experimental data are discussed in view of a recent theoretical treatment of the positron – F centre problem.
The hydrodynamical approximations in the cold nuclear matter
Authors: Padjen R.
Published: April 2011

In this work the hydrodynamic approximations in the cold nuclear matter are analyzed and compared to the zero sound solution in the long wavelength limit. It is shown that the hydrodynamical hierarchy can reasonably approximate the zero sound solution only in the case of strongly repulsive interaction parameters. When the zero sound mode is damped, the hydrodynamical approximations beyond the first sound are shown to have no physical meaning.
The vibrational frequencies of HPO
Authors: Larzilliere M. , Damany N. , My Lam Thanh
Published: April 2011

Preliminary rotational analyses of the 000–010, 000–001, 000–011, 000–020, 010–000, 001–000 bands of the [Formula: see text] transition give the P—O stretching (ν2) and the bending (ν3) frequencies of [Formula: see text] and [Formula: see text] states.
Analyse comparative à densité variable du profil de la bande ν3 de CH4 dans SF6, Ar et CCL4
Authors: Vincent-Geisse J. , Soussen-Jacob J. , Tan T. Nguyen , McClung R. E. D.
Published: April 2011

The ν3 infrared band of CH4 has been measured in liquid solutions in SF6 and CCl4 at several temperatures, and in high pressure gas mixtures with Ar at several pressures. The band profiles were compared with those computed using the semi-classical extended rotational diffusion models for molecular rotation in fluids, and values of the angular momentum correlation time, τ, determined. The density and temperature dependence of τ was in accord with the interpretation of τ−1 as a collision frequency. The mean square torques were obtained from the fourth moments of spectral contours.
Spontaneous symmetry breakdown induced by quantum effects
Authors: McKeon Gerry
Published: April 2011

The stability of the symmetric vacuum of a simple model involving two scalar fields is examined. If quantum corrections to the effective potential are included up to first order in [Formula: see text], it is found that under certain conditions the quantum corrections induce an instability in the symmetric vacuum. Possible implications of this result for other models, such as massless electrodynamics, are discussed.
Categorization of high-β equilibria in Tokamaks of arbitrary cross section
Authors: Jones R.
Published: April 2011

The problem of high-β Tokamak equilibria is studied numerically for plasmas of arbitrary cross section. The third moment of the plasma current profile is shown to be an effective and general parameter for optimizing such equilibria. Operating parameters for various equilibrium configurations are given in terms of machine requirements.
Simplified derivation of the crossing relations using the substitution rule as a guide
Authors: Morrow Richard A.
Published: April 2011

A simple derivation of the Trueman–Wick crossing relations for center of mass helicity amplitudes is presented. The method uses only Wigner rotation matrices and does not deal specifically with more general Lorentz transformations. Each particle is treated individually in turn in its own rest frame in order to discover how its helicity transforms under crossing and the substitution rule is used as a guide in determining the outcome of the analytic continuation. Crossing relations for different paths of analytic continuation in the s–t plane are discussed and it is shown that care must be exercised when dealing with weak interaction amplitudes. The method presented may be extended straightforwardly to multiparticle amplitudes.
g9/2 isobaric analogue resonances in 64,66Zn(p,γ) reactions
Authors: Rangacharyulu C. , Szöghy I. M. , St-Pierre C. , Ramavataram K.
Published: April 2011

Gamma decay schemes and angular distributions have been measured for g9/2 isobaric analogue resonances (IAR) in the 64,66Zn(p,γ) reactions. In 65Ga, the IAR is seen to be fragmented into four components at resonance energies ER = 6.810, 6.819, 6.830, and 6.835 MeV, and two fragments are observed in 67Ga at ER = 8.554 and 8.569 MeV. The total analogue–antianalogue M1 strengths are, respectively, 7 and 4% of the single particle estimates in 65Ga and 67Ga. These results are examined in the light of a model proposed by Aleshin. In 65Ga, the level at 1.286 MeV is determined to have a spin of 9/2 from angular distributions. This level is most likely a member of [Formula: see text] multiplet.
Parametric study of dissipative drift modes and their dynamic stabilization in a weakly ionized plasma
Authors: Boucher C. , Mah S. Q. , Andel H. W. H. Van , Teichmann J.
Published: April 2011

A detailed experimental study is made of dissipative drift modes in a weakly ionized plasma. The appearance of various modes as the plasma parameters are changed is compared with theory. A detailed study of the m = 3 mode in cylindrical geometry shows good agreement between experiment and a locally applied theoretical model. A method of dynamic stabilization using oscillating azimuthal magnetic field is studied and theory and experiment are compared for the m = 3 mode.
Characteristics of the midlatitude maximum in the O I 5577 Å airglow emission rate
Authors: Cogger L. L. , Khaneja R.
Published: April 2011

An analysis of O I 5577 Å airglow limbs observed on the night side of the earth by a scanning photometer on board the ISIS 2 satellite has provided sufficient data to establish the existence of a prominent midlatitude maximum in the airglow emission rate. The maximum occurs near 40° latitude in the winter and near 30° in the summer, with the winter hemisphere maximum a factor of 1.6 larger than the summer hemisphere maximum. The emission rate varies by a factor of about 4 during the year with the maximum occurring several weeks after the autumn equinox. It is suggested that these spatial and temporal variations are due to the distribution of atomic oxygen which, in turn, is influenced by large scale dynamical processes in the lower thermosphere.