It has already been shown that the Fe II absolute oscillator strengths (f-values) measured by Warner
NASA Technical Reports Server (NTRS)
... ATOMIC SPECTROSCOPY, COPPER, INTENSITY, ABSORPTION SPECTRA, HARTREE FOCK APPROXIMATION, VISIBLE SPECTRA ...
DTIC Science & Technology
Using collinear fast beam cw dye laser modulation spectroscopy, accurate lifetimes in Th II have been measured. Together with known branching ratios, these lifetimes have allowed the determination of absolute oscillator strengths for Th II. This element is of astrophysical interest as a chronometer for stellar and galaxy evolution, ...
NASA Astrophysics Data System (ADS)
Reflection spectra of anthracene are analysed by Kramers-Kronig method in the wavelength region from 192 to 600 m?. The oscillator strength of the first electronic transition A1g?B2u is obtained with Lorentz field correction. The oscillator strength for individual vibronic band at room temperature is in excellent ...
Measurements of atomic lifetimes by the beam-foil technique and branching ratios by use of a gas-flow stabilized arc have led to an experimental determination of absolute and relative oscillator strengths of V I and V II. Some lifetimes of V III are also presented. (auth)
Energy Citations Database
Measurements of atomic lifetimes by the beam-foil technique and branching ratios by use of a gas-flow stabilized arc have led to an experimental determination of absolute oscillator strengths of Ti II. Some lifetimes of Ti I, Ti III, and Ti IV are also presented. (auth)
We report experimental measurements of electron scattering by xenon atoms for various values of impact energy (15 to 450 eV) and scattering angle (0degree to 90degree). The intensities of the peaks in the energy-loss spectra have been used to evaluate the relative values of the effective and generalized oscillator strengths of the strongest transitions ...
Absolute transition probabilities and oscillator strengths are estimated for the electronic bands of CS(+) systems. Franck-Condon factors, r-centroids, band origins, transition probabilities, band oscillator strengths, and positions of electronic bandheads observed in the laboratory and ...
The relative intensities of 27 optical transitions in the Eu II spectrum are measured, and the excited state lifetimes absolute oscillator strengths are computed. A grating monochromator is used to observe selectively the emitted lines in the wavelength region from 350-750 nm, and a tungsten ribbon lamp is used for the calibration of ...
Saturation technique has been employed to measure the oscillator strength distribution in spectra of helium lithium using an electrical discharge cell a thermionic diode ion detector respectively. The photoabsorption cross sections in the discrete or bound region (commonly known as f-values) have been determined form the Rydberg series accessed from a ...
Vertical excitation energies as well as related absolute photoabsorption oscillator strength data are very scarce in the literature for methane. In this study, we have characterized the three existing series of low-lying Rydberg states of CH4 by computing coupled cluster linear response (CCLR) vertical excitation energies together with ...
PubMed
An alternative method is described for the measurement of absolute optical oscillator strengths (cross sections) for electronic excitation of free atoms and molecules throughout the discrete region of the valence-shell spectrum at high energy resolution (full width at half maximum of 0.048 eV). The technique, utilizing the ...
Absolute atomic transition probabilities or oscillator strengths, for transitions between excited states have historically been difficult to determine. Oscillator strengths are needed for several important problems in physics including, determination of the constituent concentrations of stellar ...
... Title : SOME OSCILLATOR STRENGTH MEASUREMENTS FOR ATOMIC NITROGEN AND A STUDY OF NITROGEN AFTERGLOWS BY ...
A reliable estimate of the platinum abundance in HgMn stars has been obtained for the first time. It is as high as log A(Pt) = 6, on the scale log A(H) = 12; the Pt abundance often matches the remarkably high abundances of Hg already known in these stars. The results are based on calculations of theoretical oscillator strengths which were applied to high ...
Absolute x-ray absorption cross sections of a regular bacterial surface-layer protein deposited on a naturally oxidized silicon substrate were determined experimentally. Upon separation of the partial cross sections of the three relevant 1s absorption edges, the oscillator strengths of the 1s{yields}{pi}* excitations within the ...
The lifetimes of twelve levels of Ho I and two levels of Ho II have been measured by the multichannel delayed-coincidence method. Using the lifetime data for the Ho I levels, the absolute oscillator strengths of the Ho I lines were calculated. The relative f values of these lines had been measured previously by the hook method. f/sub ...
A modified version of the method of oscillator-strength determination is presented which can be useful for various elements from the iron group and which was tested with V III as an example. An attempt is made to describe experiments in which spectra of V II and V III were produced simultaneously in a wall-stabilized cascade arc containing a mixture of VOCl3 and helium. ...
The spectrophotometric technique is currently the only technique used to characterize the gas complexation reactions between lanthanide and actinide halides and group III halides. In several cases a temperature-dependent molar absorptivity has been observed. To explain this observation, a temperature-dependent line width and ground state population distribution as well as the existence of several ...
... Title : EFFECT OF THE FORM OF GRINDING AND THE ABSOLUTE DIMENSIONS OF PARTS ON THE CORROSION-FATIGUE STRENGTH OF ...
The absolute double differential cross section (DDCS), the generalized oscillator strength distribution (GOSD), and the ionization efficiency of ammonia (NH3) were investigated from the threshold to 40 eV under the condition of 200 and 400 eV incident electron energies and 6 and 8 degree scattering angles using electron energy-loss ...
A knowledge of the abundances of lanthanide ions in stellar photospheres is valuable in astrophysics, especially for chemically peculiar stars. However, the determination of elemental abundances is often limited by inadequate knowledge of oscillator strengths. Combining independently measured values of radiative lifetimes and branching fractions is an ...
... Absolute negative conductance, unstable plasma oscillations and parametric amplificatoin of intense field harmonics destroy these states. ...
... Title : THE OSCILLATOR STRENGTH OF LEAD (II) ION IN POTASSIUM CHLORIDE SINGLE CRYSTALS. Descriptive Note : Technical rept.,. ...
... Title : Experimental Measurement of Oscillator Strengths in Neutral Xenon using the Roschdestvenskii Hook Method. Descriptive Note : Interim rept. ...
... OSCILLATOR STRENGTHS FOR THE 2A,)- K2.B TRANSITION OF NH2 ...
New independent variables are suggested that can be used to fit optical oscillator strength distributions in an efficient manner. (GHT)
DOE Information Bridge
... have been calculated with the Coulomb approximation for the ... OSCILLATION, RESONANCE ABSORPTION, ATOMIC ENERGY LEVELS, TABLES ...
Astrophysical implications of a new scale of accurate oscillator strengths obtained for Eu II are discussed. A new value of the solar photospheric abundance of Europium is derived: A(Eu) equals 0.51 plus or minus 0.08, in the usual logarithmic scale. Some stellar implications of the new gf-values are also presented.
The authors have measured branching ratios for all classified transitions from seven levels in neutral chromium whose lifetimes had previously been measured using the beam-foil technique, and have deduced corresponding gf-values for 44 lines in CrI. Sever...
National Technical Information Service (NTIS)
Context: The solar photospheric element abundances are generally in good agreement with the meteoritic CI chondrite abundances, with the exception of a small number of elements including manganese. The solar photospheric abundances, determined using model atmospheres, include laboratory oscillator strengths where available. However, the current laboratory ...
Absorption spectra of thin films of glycine (Gly), alanine (Ala), valine (Val), serine (Ser), leucine (Leu), phenylalanine (Phe) and methinine (Met) were measured in absolute values of absorption cross section ?(E) for the photon energy E from 3 to 250 eV. We translated ?(E) into the optical oscillator strength distribution df/dE and ...
The authors report absolute differential and integral cross section measurements for electron-impact excitation of the A (1)B(1) electronic state of water. This is an important channel for the production of the OH (X (2)Pi) radical, as well as for understanding the origin of the atmospheric Meinel [Astrophys. J. 111, 555 (1950)] bands. The incident energy range of our ...
In this work we propose a novel circuit design: a double-resonance oscillator. Its oscillation shows two oscillation modes: frequency locking to the quartz crystal resonance and LC resonance oscillation. Transition of the oscillation mode and the strength of ...
The threshold for an absolute parametric instability of the decay type along with the growth rates for two types of interacting oscillations are obtained theoretically for an inhomogeneous plasma layer. (AIP)
Absolute photoionization cross sections for Kr{sup 5+} were measured in the photon energy range 74-175 eV using synchrotron radiation. For comparison, a detailed energy scan of the electron-impact ionization cross section was made in the same energy range and normalized to previously published absolute measurements. The Flexible Atomic Code and Cowan ...
The recently built electron-energy-loss spectrometer (EELS) (typical FWHM 60 meV) was employed to measure the EELS spectra of argon in the discrete and autoionization resonance regions at a 2.5-keV impact energy and a mean scattering angle of 0{degree}. Relative differential optical oscillator strength spectra were established by multiplying the EELS ...
... Title : A CHEMICAL DETERMINATION OF THE OSCILLATOR STRENGTH OF F-CENTERS. Descriptive Note : Technical rept. no. 8,. ...
Lifetimes have been measured using time-resolved laser-induced fluorescence for 16 odd levels in the doublet, quartet and sextet systems of Mo II, with energies in the range 48 000-61 000 cm?1. Absolute transition probabilities and oscillator strengths are determined for 110 UV and visible transitions (208 < ? < 485 nm) from a ...
The quantitative relation between fast electron impact and photoabsorption is discussed with reference to simulation of the technique of photoelectron spectroscopy. An apparatus is described that employs coincidence detection of scattered and ejected electrons resulting from ionization over a range of energy losses up to 70 eV. Absolute ...
Absolute extinction coefficient and oscillator strength values of nine gaseous benzenes (toluene, o-, m-, p-xylene, 1,2,4-, 1,3,5-trimethylbenzene, 2,3,5,6-tetramethylbenzene, pentamethylbenzene, and hexamethylbenzene) were recorded with moderate resolution in the region of the lower valence-shell electronic transitions (4 to 7 eV). ...
The electron--proton coincidence method was used to determine the absolute differential cross sections for electron--atom scattering in helium. These studies were made for excitation of the 4/sup 1/S, 4/sup 1/D, 5/sup 1/S and 5/sup 1/D states which are not resolved by an electron spectrometer; the experiments were performed for incident energies from 50 to 200 eV and ...
The role played by the coupling forms and coupling strengths in determining the induced loss factor of a master oscillator due to its coupling to a set of satellite oscillators is assessed and evaluated.
Calculations for the oscillator strengths of Werner bands of H2, using all three operators, length, velocity and acceleration is reported. (Author)
... Compilation Part Notice ADP013301 TITLE: Excitons and Exciton Oscillator Strengths in Two-Dimensional Superlattices ...
... Accession Number : ADP013301. Title : Excitons and Exciton Oscillator Strengths in Two-Dimensional Superlattices. Descriptive ...
An account is given of progress in work on (1) the determination of band oscillator strengths of the
Absorption-oscillator-strength measurements for the principal series in cesium were measured using a
The oscillator strengths of dipole transitions were computed for some rather highly ionized ions using the Coulomb approximation method of Bates and Damgaard. (Author)
... Accession Number : ADA213837. Title : Calculation of Einstein A Coefficients and Oscillator Strengths for the A 2A(1) - X 2B(1) Transition of NH(2). ...
Absolute optical oscillator strength densities for the excitations of the electrons 4p, 4s, and 3d have been measured. Their absolute optical oscillator strengths have also been obtained. An enhancement above the 4p ionization threshold in the photoabsorption spectrum was ...
We report an optoelectronic feedback loop suitable for generating noise-free interference patterns oscillating at arbitrary waveforms. The technique allows controlling the frequency detuning between the interfering beams through a phase modulator in a closed-loop interferometer. We use the dither signal method and propose a quasisynchronous demodulation scheme to create a ...
Electrons moving in graphene behave as massless Dirac fermions, and they exhibit fascinating low-frequency electrical transport phenomena. Their dynamic response, however, is little known at frequencies above one terahertz (THz). Such knowledge is important not only for a deeper understanding of the Dirac electron quantum transport, but also for graphene applications in ultrahigh-speed THz ...
A chain of three-oscillator system was constructed with living biological oscillators of phasmodial slime mold, Physarum polycehalum and the oscillation patterns were analyzed by the symmetric Hopf bifurcation theory using group theory. Multi-stability of oscillation patterns was observed, even when the coupling ...
An absolute calibration technique for a spontaneously fissioning nuclide (which involves no arbitrary parameters) allows unique determination of the detector efficiency for that nuclide, hence of the fission source strength.
... measurements are carried out for the ... temperature vacuum furnace which was ... ABSORPTION, EXCITATION, FURNACES, HIGH TEMPERATURE ...
... PROBABILITIES AND ABSORPTION OSCILLATOR STRENGTHS FOR THE ALKALI-LIKE IONS OF THE ALKALINE EARTHS AND FOR CALCIUM I. ...
Oscillator strengths and predissociation linewidths deduced in recent studies predict a dissociation
... Descriptors : *SOLID LUBRICANTS, CALCIUM ... EQUATIONS, RANGE( EXTREMES), OSCILLATION ... STRENGTH, PARTIAL PRESSURE, REACTIVE ...
We report new measurements of the absorption oscillator strength for several CH3 transitions in the vacuum ultraviolet (VUV). The methyl radical (CH3) is important in a variety of systems including flames and diamond deposition reactors. The oscillator st...
Aims: The aim of our new laboratory measurements is to measure accurate absolute oscillator strengths for neutral manganese transitions in the infrared needed for the study of late-type stars and ultracool dwarfs. Methods: Branching fractions have been measured by high resolution Fourier transform spectroscopy and combined with ...
The electronic excitation of the silicon tetrafluoride (SiF4) molecule has been studied using the angle-resolved electron energy-loss technique, at 1.0 keV incident electron energy, in the 0-50 eV energy range with an angular range of 1.5�-20.0�. The absolute generalized oscillator strength (GOS) for the 5t2?6a1 electronic ...
An account is given of progress in work on (1) the determination of band oscillator strengths of the Schumann-Runge absorption bands of (16)O2 and (18)O2 from cross section measurements conducted at 79 K; (2) the determination of the absolute absorption cross section of the Schumann-Runge bands of (16)O(18)O from optical depth ...
The absolute generalized oscillator strengths (GOSs) for 5s, 5s{sup '}, 5p [5/2]{sub 3,2}, 5p [3/2]{sub 1,2}, and 5p [1/2]{sub 0} transitions of krypton have been determined in a large K{sup 2} region at a high electron-impact energy of 2500 eV. The positions of the minima and maxima of these GOSs have been determined. The ...
Rydberg states in highly stripped fast oxygen and neon ions are formed in the interaction with thin carbon foil and gas targets. They are ionized in the field of an electrostatic parallel-plate spectrometer and produce pronounced structures in the electron energy spectra at apparent energies higher than the cusp peak. The measured electron yield shows marked oscillatory structures in the ...
The generalized oscillator strengths (GOSs) for discrete and continuum S 2{ital p} excitations of SF{sub 6} have been derived in the momentum transfer range ({ital K}{sup 2}) of 1--20 a.u.{sup {minus}2} from the angular variation of the relative differential cross section for inelastic electron scattering. The experimental techniques and data processing ...
InSe thin films are obtained by evaporating InSe crystal onto ultrasonically cleaned glass substrates under pressure of �10-5 Torr. The structural and compositional analysis revealed that these films are of amorphous nature and are atomically composed of �51% In and �49% Se. The reflectance and transmittance of the films are measured at various temperatures (300 450 K) in the incident photon ...
for substantial damages to occur, it is assumed that the absolute strength measured on the Richter scale must such earthquakes of the given type with the following absolute strength measured on the Richter scale: 4.8, 3.5, 3
E-print Network
... of absolute echo levels from marine acoustic targets (schools of pelagic ... Sonar, Target strength, Very low frequency, Fishes, Underwater sound. ...
Using synchrotron radiation, absolute single photoionization cross sections were measured in the photon energy ranges 39.05--143.2 eV for Kr 3+ , 59.1-- 155.9 eV for Kr 4+ and 74--175 eV for Kr 5+ . Absolute double photoionization cross sections for Kr 3+ were also measured in the energy range 120.6--137. 7 eV. For comparison, detailed energy scans of the ...
... than the absolute acoustic backscattering levels ... sonars in fisheries acoustics, the estimation of ... on target strength measurements and abundance ...
We report the observation of anisotropy ratio ? and interlayer coupling strength oscillations with variation of metal layer thickness on Mo/Si multilayer series with constant Si layer thickness. These oscillations correlate with previously found oscillations of TC, R300/Rn and dHc?/dT. The giant amplitude of ? ...
This paper introduces dual-quaternion product how the representation of curve solution to oscillating systems, under dissipation and external periodic action, as well as strength of coupling.
The absolute quantum efficiency for the destruction of U centers and the formation of anion vacancies in KBr at 78�K has been found to be 0.61+/-0.07 when the U optical absorption band is bleached by 225-m? radiation absorbed at the maximum of the U band. The quantum efficiency decreases significantly as the energy of the absorbed photons increases. It is suggested that the ...
A detailed comparison of experimental and theoretical SNR in an IR laser heterodyne system has been made with three different signal analyzers. Good agreement, considerably better than a factor of 1.5, is reported. Accurate allowance was made for transmission in the receiver optics, the effective quantum efficiency of the detector due to shot noise domination by the local ...
We present a simple and efficient method for measuring the atomic lifetimes in order of tens of microseconds and demonstrate it in the lifetime determination of barium Rydberg states. This method extracts the lifetime information from the time-of-flight spectrum directly, which is much more efficient than other methods such as the time-delayed field ionization and the traditional laser induced ...
Electron-impact excitation of the 6p7s {sup 3}P{sub 1} state of Pb atom has been investigated both experimentally and theoretically. Differential cross sections (DCSs) were measured at incident electron energies of E{sub 0}=10, 20, 40, 60, 80, and 100 eV and small scattering angles up to 10 degree sign using a crossed electron-atom beam technique. The forward scattering function method has been ...
We report an experimental absolute oscillator strengths for 18 UV lines of Ru II, obtained by combining laser-induced flourescence measurements of radiative lifetimes and branching fractions from line intensities in a calibrated Fourier-transform spectrum Hubble Space Telescope/Goddard High Resolution Spectrograph (HST/GHRS) ...
The critical current, oscillation frequency, and characteristic wave number for the excitation of absolute instability in gyropeniotron amplifiers are calculated from the linear dispersion relation by following the Briggs--Bers criterion. Numerical results are presented for some cases of interest.
The Karman vortex street in the wake of a circular cylinder is shown to be due to an absolute instability of the flow in the near wake. A new means of instability analysis is used, involving mappings from the complex k plane to the complex ..omega.. plane.
A living coupled oscillator system was constructed by a cell patterning method with a plasmodial slime mold, in which parameters such as coupling strength and distance between the oscillators can be systematically controlled. Rich oscillation phenomena between the two-coupled oscillators, ...
An integral equation is derived to describe the absolute instability in an inhomogeneous plasma.(AIP)
... are synchronized to the 60 Hz line frequency and contain some type of back up oscillator to insure continued operation during AC power outages. ...
By using external-gain, hydrogen-maser oscillations were obtained at cavity Q values and beam intensities far below those required for a conventional hydrogen maser. Frequency-pulling measurements and absolute frequency determinations of the hydrogen mase...
Viscometers specially designed for molten salts were made. One is a oscillating cup type and the other is a capillary type. In the case of the oscillating cup viscometer, the viscosity is determined absolutely through the period and the logarithmic decrem...
The operation of the gyrotron travelling wave amplifier is based on the convection cyclotron maser instability. It is found that this convective instability may become absolute (nonconvective) at a sufficiently high current level, resulting in oscillation...
The paper describes a new, high-precision, oscillating-disk viscometer in which it is possible to make absolute determinations of the viscosity of gases at atmospheric pressure in a temperature range 20-950 C, approximately. The effect of differential the...
Absolute photoionization measurements were performed for a mixture of 2P3/2o ground-state and 2P1/2o metastable-state Ca3+ ions over the photon energy range 65.7-104.6 eV by merging an ion beam with a beam of monochromatized synchrotron radiation. The ionization threshold energy of the 2P3/2o ground state was measured to be 67.063 � 0.015 eV, which is 0.207 eV lower than the ...
... of dislocations from the points of their ... ensures high strength properties in these materials. ... 2d), studied during bending oscillations, the following ...
Precision measurements of atomic lifetimes are important to the analysis of data from many areas of physics and provide fundamental atomic structure information. Scientists in the fields of astrophysics, geophysics, and plasma fusion all depend on oscillator strengths to determine the relative abundances of elements. Assessing the operation of discharge ...
The mean excitation energy for the stopping power of matter, usually expressed by symbol I, is the only nontrivial material property in Bethe's [Ann. Phys. 5, 325 (1930)] asymptotic stopping-power formula. It is therefore a crucial input for the evaluation of stopping power for swift charged particles. To calculate the I value of a material from its definition, it is necessary to know the ...
We have used two methods to measure the oscillator strength of the transition between the ground and 17992 cm/sup /minus/1/ level in /sup 174/Yb. In the first technique we observe the population oscillations of a two-level system due to resonant laser excitation. The measurement of the oscillation frequency vs ...
Calculations based on the Hartree-- Slater model of the atom were performed and indicate an often erratic dependence of the x-ray oscillator strength on atomic number, particularly for transitions involving an outer and an inner subshell where a dor f-subshell is filling. (auth)
The dipole oscillator-strength distribution df/depsilon for a single continuum excitation of an atom or molecule is a function of the kinetic energy epsilon of an outgoing electron. The distribution describes many optical phenomena such as absorption, ref...
Three experimental curves of growth have been constructed for Fe II lines of the solar spectrum with different sets of oscillator strengths. The excitation temperatures derived from these curves are 6050K, 6100K and 5150K, respectively.
The dependence of atomic oscillator strengths (f values) on nuclear charge, which leads to systematic trends along isoelectronic sequences, is discussed with particular reference to beam foil spectroscopy. The theoretical background for the nuclear charge...
Radiant emission from shock-heated gases about hypersonic projectiles yields oscillator strengths in
Results of semiempirical open-shell model potential calculations for oscillator strengths in N{sup +} are presented. The authors consider states with principal quantum numbers for the valence electron up to 12 and orbital angular momentum quantum numbers up to 4.
Open-shell semiempirical model potential methods are used to calculate oscillator strengths for neutral atomic carbon. Results are presented for principal quantum numbers up to 12 and orbital angular momentum quantum numbers up to 4.
Oscillator strengths for Y III and Zr III in the region 1190-3100 A have been calculated for transitions from all levels below 13 eV. The presence of these spectra in IUE observations of chemically peculiar stars is discussed.
Semiempirical model-potential methods are used to calculate energy levels, wavelengths, and oscillator strengths for the copper and zinc isoelectronic sequences out to Mo XIV and Mo XIII, respectively.
Using the Multiconfiguration Optimized Potential Model, calculations of oscillator strengths in the length, and velocity formulation for a large number of transitions in the Aluminium isoelectronic sequence from Si II through K VII, have been performed. T...
Vibronic bands of polycyclic aromatic hydrocarbons (PAHs) in the UV/visible range are often used to estimate the abundances of PAHs in the interstellar medium by comparing laboratory-measured spectra with astronomical observations. We investigate the errors introduced by associating theoretical electronic oscillator strengths with individual vibronic bands ...
The concept of mean excitation energy, I, and its relation to stopping-power measurements are briefly discussed. The recent theoretical and experimental advances in obtaining I directly from oscillator-strength distributions for atoms, molecules, solids, ...
Quantum-mechanical expressions for nonresonance-dipole light-scattering cross sections are related to corresponding expressions for oscillator strengths and refractive indices. In particular, Rayleigh and Raman cross sections for atoms are expressed in te...
Band oscillator strengths (f-values) for four bands of the Fourth Positive system (A (1)Pi - Chi(sup
In order to calculate the dichroism of oriented polymer molecules containing polyene units, it is necessary to know the oscillator strength of a polyene unit as a function of its degree of conjugation. Free electron and molecular orbital calculations of s...
The oscillation modes present in the 'TOPSY' thermally generated cesium plasma device were investigated experimentally; oscillation frequency spectra and three-axis maps of relative phase were studied as functions of axial magnetic field strength, electro...
The quasi-biennial oscillation modulates the strength of both the Arctic and Antarctic stratospheric
... radicals are expected to be of importance in the combustion chemistry of double ... depend heavily on the values chosen for the heats of formation of ...
