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Showing papers on "Stark effect published in 1970"


Journal ArticleDOI
TL;DR: In this paper, the thermal average of the time development operator for upper and lower state interaction is presented, which contains the effect of finite interaction time between the radiator and perturbers to all orders, thus avoiding a Lewis type cutoff.
Abstract: The unified theory has been generalized for the case of upper and lower state interaction by introducing a more compact tetradic notation. The general result is then applied to the Stark broadening of hydrogen. The thermal average of the time development operator for upper and lower state interaction is presented. Except for the time ordering it contains the effect of finite interaction time between the radiator and perturbers to all orders, thus avoiding a Lewis type cutoff. A simple technique for evaluating the Fourier transform of the thermal average has been developed. The final calculations based on the unified theory and on the one-electron theory are compared with measurements in the high and low electron density regime. The unified theory calculations cover the entire line profile from the line center to the static wing and the simpler one-electron theory calculations provide the line intensities only in the line wings.

110 citations


Journal ArticleDOI
TL;DR: Magnetic and electric deflection analysis of the scattering of Cs + NO2 shows that the principal product is a paramagnetic, polar molecule as mentioned in this paper, which has a pseudo-first-order Stark effect.
Abstract: Magnetic and electric deflection analysis of the scattering of Cs + NO2 shows that the principal product is a paramagnetic, polar molecule. Magnetic analysis of the K + NO2 system indicates that the scattered signal is paramagnetic; a similar study of Na + NO2 shows a small yield of diamagnetic product. For the analogous reactions with CH3NO2, the product is diamagnetic and has a pseudo‐first‐order Stark effect. From these data and thermochemical arguments the principal alkali‐containing products are identified as: for Cs + NO2, a 2Σ electronic state of CsO; for Na + NO2, probably a 2Π state of NaO; for M + CH3NO2, almost certainly MNO2 in a singlet state. The NO2 results indicate that the ground state of the MO molecule changes from 2Π for LiO (the only species which had been previously observed) to 2Σ for CsO. The usual differential surface ionization detection fails for Cs + NO2 and consequently only a very rough estimate of the scattering is obtained; this indicates that the total reaction cross secti...

95 citations


Journal ArticleDOI
TL;DR: Very accurate Stark effect measurements were made on rotational transitions of nitrous oxide and propyne-d3 as mentioned in this paper, which gave an electric polarizability anisotropy of 3.78780,± 0.16 A3.
Abstract: Very accurate Stark effect measurements were made on rotational transitions of nitrous oxide and propyne‐d3. Measurements were made with a microwave spectrometer incorporating a special parallel‐plate absorption cell capable of sustaining large magnitude electric fields and of producing very homogeneous fields in the absorption region. Analysis of the data gives an electric polarizability anisotropy of 3.222 ± 0.046 A3 for nitrous oxide and of 2.7 ± 0.6 A3 for propyne‐d3. The dipole moment of nitrous oxide was determined to be 0.160830 ± 0.000016 D. For propyne‐d3, there is evidence for a K dependence of the dipole moment. The determined values for the J = 3 → 4 transition are 0.78780 ± 0.00013 D (K = 0), 0.78765 ± 0.00021 D (K = 2), and 0.78741 ± 0.00014 D (K = 3). Stark effect data reported previously for OCS were reanalyzed using a refined method of statistical analysis and the new molecular beam value for the OCS dipole moment to determine the revised OCS polarizability anisotropy of 4.67 ± 0.16 A3. In each case, the error limit represents the 95% confidence level calculated in the least‐squares analysis, but does not include the uncertainty in the dipole moment value for OCS which was used as a standard in the data reduction.

71 citations


Journal ArticleDOI
TL;DR: The microwave spectrum of pyridine has been observed between 8000 MHz and 18,000 MHz as mentioned in this paper, and the rotational constants are A = 6276.86 MHz, B = 6067.18 MHz, and C = 3084.49 MHz.

71 citations


Journal ArticleDOI
TL;DR: In this paper, the energy levels of a rigid rotator in an electrical field are calculated by diagonalization for the intermediate region and its deviation from the two limiting cases is briefly discussed.
Abstract: The motion of a rigid rotator in an electrical field is well known for small fieldstrengths where it is identical with the second-order perturbation of the Stark effect. At large fieldstrengths, the rotator becomes almost fixed about the field direction and its levels coincide with those of an harmonic oscillator. In this paper the energy levels are calculated by diagonalization for the intermediate region and its deviation from the two limiting cases is briefly discussed.

60 citations


Journal ArticleDOI
TL;DR: In this paper, the Stark effect on the rotational lines of the 1+0 band of the 3A2-1A1 transition of formaldehyde has been studied using field strengths up to 25 ǫkV/cm.
Abstract: The Stark effect on the rotational lines of the 1+–0 band of the 3A2–1A1 (π* ← n) transition of formaldehyde has been studied using field strengths up to 25 kV/cm. Measurements of the Stark splitti...

58 citations


Journal ArticleDOI
TL;DR: In this paper, the nuclear quadrupole hyperfine structure, which originates from the 33S and 73Ge nuclei, has been measured for nearly all of the molecules containing these nuclei.
Abstract: Stark effect measurements on the pure rotational transitions of the Group IV/VI compounds are reported. The electric dipole moments of the molecules with the highest natural abundance were determined for the ground vibrational state. For SnS the variation of the dipole moment with vibrational state was also measured. The nuclear quadrupole hyperfine structure, which originates from the 33S and 73Ge nuclei, has been measured for nearly all of the molecules containing these nuclei. A systematic trend in the dipole moments of the Group IV/VI compounds is reported and compared with the alkali halides.

52 citations


Journal ArticleDOI
TL;DR: Using a mode-locked ruby laser, stimulated rotational and vibrational Raman scattering was observed in a variety of high-pressure gases, where previously no stimulated scattering has been reported as discussed by the authors.
Abstract: Using a mode‐locked ruby laser, stimulated rotational and vibrational Raman scattering has been observed in a variety of high‐pressure gases, where previously no stimulated scattering has been reported. Pulse energy conversion efficiencies as high as 70% have been obtained. Evidence for a strong optical Stark effect is seen in the gases producing rotational scattering. Self‐focusing in a collimated beam is observed in N2O and CO2.

48 citations


Journal ArticleDOI
TL;DR: In this paper, an exhaustive reanalysis of a 3Π optical data is presented, in which the spinorbit, rotational, spin spin dipole-dipole, and potential energy parameters have been accurately determined.
Abstract: The radio‐frequency spectrum of the first four (υ = 0–3) vibrational states of the a 3Π metastable state of 12C16O has been measured in molecular beam electric resonance from 0 to 500 MHz. Lambda doubling transitions have been observed in J = 2–7 of Ω = 2, and in J = 1 and 2 of Ω = 1 at zero electric and magnetic field and as a function of electric field. An exhaustive reanalysis of a 3Π optical data is presented, in which the spin–orbit, rotational, spin–spin dipole–dipole, and potential‐energy parameters have been accurately determined. Together with parameters determined from the rf spectrum, the resulting set of fine structure parameters predicts the complete lambda doubling spectrum to better than 1 in 104 for J = 0–50, υ = 0–3. The predicted frequencies below 5 GHz are tabulated for possible radio‐astronomical measurement of a 3Π CO. The Stark effect allows the a 3Π dipole moment to be determined to an absolute accuracy of 2 in 104, and the small dependence upon spin–orbit, vibrational, and rotation...

46 citations


Journal ArticleDOI
TL;DR: In this article, the authors investigated the properties of intrinsic and bound excitons in CdS with Cl donor concentrations over a wide range by measuring emission and reflection spectra at liquid helium temperature.
Abstract: Properties of intrinsic and bound excitons in CdS with Cl donor concentrations over a wide range are investigated by measuring emission and reflection spectra at liquid helium temperature. As a result two characteristic properties of excitons are observed. 1) The binding energy of excitons decreases with increasing donor concentration, but the dependence on the concentration is different between intrinsic and bound excitons. 2) The emission line due to bound exciton shows asymmetric broadening with a tail extending to lower energies at high donor concentrations. According to Hanamura's theoretical work in the succeeding paper, the first behavior of the decrease of binding energy is ascribed to the screening effect of donor electrons on excitons. The second feature of anomalous line shape is concluded to be a consequence of the Stark effect due to charged impurities on bound exciton. On the basis of these interpretations very good agreement has been obtained between experiment and theory.

42 citations


Journal ArticleDOI
TL;DR: In this paper, the Stark effect in the F-center absorption has been observed in KCl, KBr, KI, RbCl, and NaCl and the energy difference between the 2S and 2P levels, and the dipole matrix element 〈2S|z|2P〉, have been evaluated.
Abstract: The Stark effect in the F-center absorption has been observed in KCl, KBr, KI, RbCl, and NaCl. Changes of the absorption coefficient due to the electric field have been measured as a function of photon energy. From these data the energy difference between the 2S and 2P levels, and the dipole matrix element 〈2S|z|2P〉, have been evaluated

Journal ArticleDOI
TL;DR: Measured and theoretical stark-broadened line profiles and asymptotic wing approximation of hydrogen Balmer lines at specific electron density and temperature were derived in this paper for specific electron densities and temperatures.
Abstract: Measured and theoretical stark-broadened line profiles and asymptotic wing approximation of hydrogen Balmer lines at specific electron density and temperature

Journal ArticleDOI
TL;DR: Stark effect in the hyperfine structure of rotational transitions of HI and HBr in the submillimeter wavelength region was investigated in this paper, with the value of the electric dipole moment of OCS as calibrant.


Journal ArticleDOI
TL;DR: Stark-broadened neutral atomic line widths and shifts, determining electron densities from H beta profiles and pressure-temperature data were used in this article to determine electron density.
Abstract: Stark-broadened neutral atomic line widths and shifts, determining electron densities from H beta profiles and pressure-temperature data

Journal ArticleDOI
TL;DR: In this paper, the microwave spectrum of fluoroacetone has been studied in the region 18-35 GHz, and transitions arising from one rotamer have been assigned, and splittings of the rotational lines into A and E components have been analyzed using as a model a rigid methyl group attached to a rigid framework.
Abstract: The microwave spectrum of fluoroacetone has been studied in the region 18–35 GHz, and transitions arising from one rotamer have been assigned. This rotamer has all the heavy atoms in a plane with the fluorine and oxygen atoms trans to one another. The rotational constants are A = 8658.06, B = 4021.64, and C = 2845.12 MHz, which give Ia + Ib − Ic = 6.406 amu·A2. Stark effect measurements give the dipole‐moment components: μa = 0.907 ± 0.020 D, μb = 0.76 ± 0.05 D, μ = 1.18 ± 0.05 D. Satellite lines arising from excited states of both the methyl and CH2F torsions have been identified. The splittings of the rotational lines into A and E components have been analyzed using as a model a rigid methyl group attached to a rigid framework. This treatment gives a barrier to internal rotation of the methyl group of 1488 ± 30 cal/mole for the ground state and 1467 ± 30 cal/mole for the first excited methyl state. A model which takes into account coupling of the −CH3 and −CH2F torsional vibrations is also considered.

Journal ArticleDOI
TL;DR: In this article, the halfwidths of fifteen Stark broadened argon II lines have been measured in argon plasma behind the reflected shock wave produced in an electromagnetically driven “T” tube.
Abstract: Half-widths of fifteen Stark broadened argon II lines have been measured in argon plasma behind the reflected shock wave produced in an electromagnetically driven “T” tube. The plasma electron density was determined by the laser interferometry at three different wavelengths, while the plasma temperature was measured from relative intensities of A II lines. Temperatures were in the range 8,500–16,500 °K; electron densities varied from 1.82 to 3.94 · 1017 cm−3. The measured A II linewidths are compared with theoretical and other experimental results. It is shown that a) the broadening of A II lines is in good agreement with the theory, b) line broadening increases linearly with electron density, and c) the Stark broadened lines follow the dispersion profile to the distance of at least three halfwidths from the line center.

Journal ArticleDOI
TL;DR: In this paper, transversale electroreflectance measurements have been performed on CuCl single crystals in the region of the exciton bands, and the observed changes of reflectivity can be separated into two components corresponding to a linear and a quadratic Stark effect.
Abstract: Transverse electroreflectance measurements have been performed on CuCl single crystals in the region of the exciton bands. The observed changes of reflectivity can be separated into two components corresponding to a linear and a quadratic Stark effect of the excitons. The linear Stark effect is due to a splitting of the valence bands of CuCl, whereas in the case of the quadratic Stark effect the relative motion of the electron–hole pair is influenced by the electric field. Es wurden transversale Elektroreflexionsmessungen an CuCl-Einkristallen im Gebiet der Exzitonenbanden durchgefuhrt. Die beobachteten Reflexionsanderungen konnen in zwei Komponenten zerlegt werden, die mit einem linearen und quadratischen Starkeffekt der Exzitonen zusammenhangen. Der lineare Starkeffekt wird durch die Aufspaltung der Valenzbander von CuCl verursacht, wahrend beim quadratischen Starkeffekt die Relativbewegung des Elektron–Lochpaares durch das elektrische Feld beeinflust wird.

Journal ArticleDOI
TL;DR: In this paper, the rotational fine structure of the 0-0 band of the lowest lying singlet π*← π state of fluorobenzene was investigated.
Abstract: A Stark effect is observed in the rotational fine structure of the 0–0 band of the lowest‐lying singlet π* ← π state of fluorobenzene. Splittings are found in both P and R branches. This enables us to determine the excited‐state dipole moment to be μ′ = 1.96 ± 0.07 D. This result is discussed in relation to previous measurements on substituted benzenes, and it is shown that the previously observed correlation between structure and dipole moment for excited states also extends to fluorobenzene.

Journal ArticleDOI
TL;DR: In this article, a 10 kJoule thetapinch experiment was conducted and the line profiles recorded were given in the usual S(α)-representation and their halfwidth-density dependence was tabulated.
Abstract: Helium plasmas having temperatures of 15–23 eV and electron densities of 0.8–1.6×1017 cm−3 were reproducibly established in a 10 kJoule thetapinch experiment. Radial and axial homogeneity of the plasma parameters in the discharge column could be achieved very satisfactorily by superimposing an axial magnetic bias field antiparallel in direction to the main thetapinch field. This plasma was well suited for Stark profile measurements on the He II-lines (4,686, 3,203, 2,733, 2,511 A) in the visible and near ultraviolet and on the He II-lines (1,215, 1,085, 1,025, 992 A) in the vacuum-UV-region. The line profiles recorded are given in the usualS(α)-representation and their halfwidth-density dependence is tabulated. Comparison is made with line shapes from other authors where available.

Journal ArticleDOI
TL;DR: In this paper, the microwave spectrum of acetonitrile N-oxide has been analyzed and it has been shown that the molecule is a symmetric top and that the dipole moment is 1.50 × 10−29 C m (4.49 D).

Journal ArticleDOI
TL;DR: In this paper, the effect of the electric field on the spectral line shape of a two-temperature electron gas has been discussed and the relationship to quasilinear theory is given.
Abstract: When an atom is immersed in a plasma the energy levels are broadened and shifted by the interaction with the fluctuating electric field of the plasma. We discuss the effect of this field on the spectral line shape by the use of results from plasma kinetic theory. In particular we show that in the equilibrium plasma the dominant effect is from single-particle collisions although correlation effects lead to a different result from the usual impact theory. In nonequilibrium plasmas the collective modes can become important and lead to appreciable satellites on the forbidden lines. In the case of a two-temperature electron gas the plasma wave effect is considerably enhanced. The possibility of observing the satellites in unstable plasmas is discussed and the relationship to quasilinear theory is given. In particular, we show that in isotropic systems the line shape can be used to directly observe the turbulent spectrum.

Journal ArticleDOI
TL;DR: Stark broadening of singly ionized nitrogen lines measured in dense high temperature plasma behind reflected shock wave in T tube was reported in this paper, showing that the line broadening was caused by a single ionized line.
Abstract: Stark broadening of singly ionized nitrogen lines measured in dense high temperature plasma behind reflected shock wave in T tube

Journal ArticleDOI
TL;DR: In this paper, the Stark effect in the J'='2'→'3 transition was analyzed to obtain the values 1.04'±'0.02' and 0.46'± '0' for the dipole moments of CHCl3 and CFCl3 respectively.
Abstract: The Stark effect in the J = 2 → 3 transition was analyzed to obtain the values 1.04 ± 0.02 and 0.46 ± 0.02 D for the dipole moments of CHCl3 and CFCl3 respectively. Taking into account Stark and quadrupole interactions and using an approximation to the Van Vleck and Weisskopf pressure‐broadening equation, pressure‐broadened spectra for the J = 2 → 3 transition were computed for both molecules and compared with measured spectra. The results show the great effect pressure broadening can have on the general appearance of a spectrum.

Journal ArticleDOI
TL;DR: Stark broadening of neutral helium line in plasmas for electron densities measurements accuracy, comparing to H beta determined densities as mentioned in this paper, has been shown to improve the accuracy of electron density measurements.
Abstract: Stark broadening of neutral helium line in plasmas for electron densities measurements accuracy, comparing to H beta determined densities

Journal ArticleDOI
S. Bashkin1
TL;DR: In this paper, the developments in beam-foil spectroscopy since 1967 are reviewed, with particular attention given to new techniques and problems, such as excitation of neutral atoms, the identification of strange lines, charge identification, foil characteristics, the astrophysical application of mean-life data, and the Stark effect.

Journal ArticleDOI
TL;DR: In this article, the Stark effect of ammonia was used to switch three lines of N2O and CO2 10μ lasers with a 1.5-approximation of the Stark-effect.
Abstract: Q‐switching of three lines of N2O and CO2 10μ lasers has been achieved by the Stark effect of ammonia.

01 Jan 1970
TL;DR: In this article, the authors present tables of the continuum radiation from argon, nitrogen, oxygen, and air in the spectral range from 950A to 6.0 micrometers, for temperatures from 9000 to 30,000 degrees K and pressures from 1 to 30 atm.
Abstract: : The report presents tables of the continuum radiation from argon, nitrogen, oxygen, and air in the spectral range from 950A to 6.0 micrometers, for temperatures from 9000 to 30,000 degrees K and pressures from 1 to 30 atm. For the neutral atoms and singly charged ions, these tables are based on the authors previously reported experimental data, while for doubly charged ions, they are based on new quantum defect calculations of the radiation. Also included in the report are tables of the Stark widths and shifts for singly ionized argon lines at temperatures from 15,000 to 25,000 degrees K, as calculated from Griem's semi-empirical treatment. These results are compared with experimental data on the Stark shifts of several AII lines at 20,000 degrees K, which were measured in the pulsed argon arc.

Journal ArticleDOI
TL;DR: The levelcrossing method has been used for an investigation of the hyperfine structure and lifetimes in the excited 5d6s6p y 2D3/2, 5/2 states of Lanthanum I as mentioned in this paper.
Abstract: The levelcrossing method has been used for an investigation of the hyperfine structure and lifetimes in the excited 5d6s6p y 2D3/2, 5/2-states of Lanthanum I. From a detailed analysis of the measured change in intensity of the resonance light the following hyperfine interaction constants and lifetimes were deduced: Applying an additional homogeneous electric field parallel to the usual magnetic field the constants β of the quadratic Stark effect in the y 2D-states were derived from the observed shifts of the levelcrossing signals: The experimental results are interpreted theoretically by the concept of intermediate coupling using appropriate eigenvectors. The observed lifetimes and the β-values are compared with the Bates and Damgaard approximation.

Journal ArticleDOI
TL;DR: In this paper, the effect of external electric field on zero-phonon lines belonging to various types of luminescence centers in LiF and NaF activated by hexavalent uranium was investigated.