Intermolecular interactions in acetonitrile in a liquid and in a low-temperature argon matrix

IR spectra of acetonitrile embedded in an argon matrix and in a liquid are recorded. IR spectra of specimens obtained with different concentrations of acetonitrile in argon are analyzed. The spectral region of C≡N vibrations of 2200–2300 cm⁻¹ with bands of monomers and possible associates is investigated. Overlap with the band of a hot transition on the low-frequency side is responsible for the pronounced asymmetry of the band ν(C≡N). To whom correspondence should be addressed. St. Petersburg State Institute of Precision Mechanics and Optics (Technical University), 14, Sablinskaya Str., St. Petersburg, 197101, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 5, pp. 627–631, September–October, 1999.     

Electron-impact excitation cross-sections for the3 S 0−,3 P 0−, and3 D 0-States of a ruthenium atom

The excitation cross-sections of transitions of a ruthenium atom from the³ S ⁰−,³ P ⁰−, and³ D ⁰-levels are measured by the method of extended crossed beams. Based on the results of measurements, the excitation cross-sections of the states are calculated (ignoring cascade contribution). Moscow Power Engineering Institute, 14, Krasnokazarmennaya St., Moscow, E-250, 111250, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 1, pp. 9–13, January–February, 1998.     

Light-Induced shifts in the frequency of a multiphoton radiooptical SHF resonance in alkali atoms

A computation is carried out for light-induced shifts in the frequency of a multiphoton radiooptical SHF resonance in alkali atoms on the basis of the quantum formalism of spherical tensors. The components of a light-induced shift in frequency at magneto-independent 0–0– and 1,–1-transitions in⁸⁷Rb atoms under the conditions of isotopic filtration of the resonance light of pumping are calculated. The difference between the temperatures of a filter cell is discovered at which the point of zero shift in the frequency of radiooptical resonance is attained. The components of the light-induced shift of frequency in optically oriented⁸⁷Rb and¹³³Cs atoms are compared in the absence of collisional reorientation in excited state. The prevailing role of the tensor component of light-induced shift in pumping by the D₁-line of a head doublet and the effect of the orientational dependence of the frequency of a multiphoton resonance on change in the sign of the pumping source radiation polarization are noted. St. Petersburg State Polytechnical University, 29 Politekhnicheskaya Str., St. Petersburg, 195251, Russia. Translated from Zburnal Prikladnoi Spektroskopii, Vol. 65, No. 6, pp. 832–838, November–December, 1998.     

Excitation of3 G 0-states of titanium, zirconium, and hafnium atoms by electron impact

Detailed information about excitation cross-selections of spectral lines of titanium, zirconium, and hafnium atoms obtained using extended crossed beams are used for calculation of the excitation cross-sections of the³G⁰-levels of these atoms. Results are compared with cross-sections calculated in Born’s approximation. For titanium: it is found that theoretical predictions agree well with experimental data. Differences found for zirconium are explained by the single-configuration approximation used in the calculation. Moscow Power Institute, Russia, 14 Krasnokazarmennaya St., 111250, Moscow E-250, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 6, pp. 707–710, November–December, 1997.     

Dissociation-induced excitation of CsII in collisions of electrons with CsOH molecules

Dissociation-induced excitation of a singly charged cesium ion taking place as a result of collisions of electrons with CsOH molecules is investigated. Possible reaction channels in the low-energy region are discussed. It is established that sequential population plays an important role for 6p levels of Cs⁺. Moscow Power Engineering Institute, 14, Krasnokazarmennaya St., Moscow, 111250, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 2, pp. 159–165, March–April, 1998.     

Properties of zinc sulfide luminophores in thin-film structures

Ul'yanovsk State Technical University, 32, Severnyi Venets St., Ul'yanovsk, 432027, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 62, No. 3, pp. 182–185, May–June, 1995.     

Excitation cross-sections of the4Do-levels of a cobalt atom under electron collision conditions

Cross-sections of the⁴D^o-levels of a cobalt atom are determined based on the results of measurements of 880 excitation cross-sections of the CoI spectral lines. Detailed calculations of branching and cascade population are made for the levels of the terms z⁴D^o, y⁴D^o, and x⁴D^o. Results of the present work and the cross sections calculated by R. K. Peterkop in the Born approximation are shown to be in good agreement. Moscow Power Engineering Institute, 14, Krasnokazarmennaya St., Moscow, E-250, 111250, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 5, pp. 561–565, September–October, 1997.     

Peculiarities of linear scaling of cylindrical glass active elements of solid-state lasers

Optimization of the glass cylindrical active element (AE) of a solid-state laser is carried out. Dependences of the optical quality of a laser medium on scale-geometry parameters of the AE with different-intensity optical pumping are obtained. The possibility of considerable increasing of the laser efficiency by using an aperture diaphragm is shown. Baltic State Technical University, 1, 1st. Krasnoarmeiskaya St., St.-Petersburg, 198005, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 6, pp. 734–737, November–December, 1997.     

RX J0720.4-3125 as a possible example of magnetic field decay in neutron stars

We consider the possible evolution of the rotation period and magnetic field of the X-ray source RX J0720.4-3125, assuming that this source is an isolated neutron star accreting from the interstellar medium. The magnetic field of the source is estimated to be 10⁶–10⁹ G (the most probable value is about 2·10⁸ G), and it is difficult to explain the observed rotational period 8.38 s without invoking the hypothesis of magnetic field decay. For calculations we used the model of ohmic dissipation of the field in the core of the neutron star. Estimates for the accretion rate (10⁻¹⁴–10⁻¹⁶ M_⊙/yr), velocity of the source through the interstellar medium (10–50 km/s), and neutron star age (2·10⁹–10¹⁰ yrs) are obtained. Lomonosov State University, Moscow, Russia; loffe Physical and Engineering Institute, St. Petersburg, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 41, No. 1, pp. 28–35, January, 1998.     

Energy yield of photoluminescence in a system of particles with three energy levels on periodic pulse excitation

Within the framework of the probability method, we obtained analytical expressions for the luminescence power, absorption power, and energy yield of photoluminescence in a system of particles with three energy levels on periodic pulse excitation. It is shown that at certain periods and durations of exciting pulses the energy yield can be higher than under stationary excitation conditions. Mordovia State University, 68, Bol'shevistskaya St., Saransk, 430000, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 2, pp. 269–272, March–April, 1997.     

Dissociative excitation of a cesium atom in collisions of slow electrons with CsF molecules

The method of extended intersecting beams is used for studying inelastic collisions of electrons with cesium fluoride molecules. Forty-six cross-sections for dissociative excitation of the spectral lines of a cesium atom located in the spectral region 387–825 nm were used. The behavior of the sections in the spectral series of a cesium atom is investigated, which is reflected by a power law. The values of constants that are parameters in the power-law formula are determined. Moscow Power Engineering Institute, 14, Krasnokazarmennaya St., E-250, Moscow, 105835, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 20–25, January–February, 1997.     

Energy transfer as a method for investigation of the structure of electrolytes

S. I. Vavilov State Optical Institute, Russia, 199034, St. Peterburg, Birzhevaya Liniya, 12. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 62, No. 3, pp. 38–42, May–June, 1995.     

Dependence of radio emission from mercury on the structure and morphology of its outer layers

We present the results of a theoretical study of the dependence of radio emission from Mercury at wavelengths 0.3–76.8 cm on the structure and composition of its outer layer. Employing different models for the structure of this layer, we show that the radiative component of the heat flux strongly influences the effective temperature and its spectral characteristics. Using the two-stratum model, we demonstrate that account of morphological inhomogeneity over the depth of the outer layer is crucial for interpreting the data on radio emission from Mercury measured with high resolution over the planet’s surface. The obtained results may be useful for comparing experimental data with theory to determine the physical characteristics of the upper cover of Mercury. The results of this paper were partially reported at the XXVII Radio Astronomical Conference (St. Petersburg, November 10–14, 1997) [1]. Radiophysical Research Institute, Nizhny Novgorod, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 42, No. 3, pp. 203–214, March 1999.     

Influence of the Elemental Composition and Concentration of Surfactants on the Atomic Absorption of Chromium

Systematic investigations of the influence of the elemental composition and concentration of surfactants on the atomic absorption of chromium have been carried out. It is shown that sodium dodecyl sulfate maximally increases the analytical signal and selectivity in chromium determination. The atomic-absorption technique of determining the quantitative content of chromium in sewage of industrial enterprises with application of sodium dodecyl sulfate as a chemical modifier has been developed. The detection limit for chromium is 1.2 μg/dm³. Reported at the 5th All-Russia Conference on Analysis of Environmental Objects “Ekoanalitika-2003” with participation of foreign scientists, October 6–10, 2003, St. Petersburg, Russia. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 4, pp. 546–550, July–August, 2005.     

Depolarization loss of interference-pattern contrast when probing radially loaded cylindrical glass laser matrices

Results of an investigation of the depolarization loss of interference-field contrast are presented. The loss of contrast was found experimentally and simulated numerically for different interferometric schemes: with lateral and radial shifts and with a reference beam. It is found that the original polarization of the probing radiation affects substantially the integral contrast of the interference field. Baltic State Technical University, 1, 1st Krasnoarmeiskaya St., St.-Petersburg, 198005, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 1, pp. 62–66, January–February, 1998.     

A study of the optical absorption induced in vacuum thermolysis of aluminum trihydroxide

The diffuse reflection spectroscopy technique was used to investigate the color centers (CC) in the products of thermolysis and photolysis of disperse Al(OH)₃ in a vacuum. The spectra were recorded in situ in the region of 2.5–6.0 eV and 4000–12,000 cm⁻¹. It was found that in thermolysis of Al(OH₃) production of Al is accompanied, by transformation of the IR spectra of the compound and overtone vibrations of OH groups and by the appearance of an absorption band (AB) at 4.0 eV with a shoulder at 4.4 eV. A similar AB is induced by UV irradiation of Al(OH)₃ in a vacuum. In the position of the maximum and shape, the AB at 4.0 eV in aluminum oxide produced by thermolysis of Al(OH)₃ coincides with the AB of CC responsible for light- and temperature-stimulated degradation of white anode oxide coatings on Al(Al-AOC). This suggests that in Al-AOC, CC are formed in decay of structural O_mH_n groups. In Al oxide and in Al-AOC, their nature is discussed with the use of data on optical absorption of radiation-induced defects in Al₂O₃. Research Institute of Physics at St. Petersburg State University, St. Petersburg 1, Ul’yanovskaya St., Petrodvorets St. Petersburg, 198904, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 3, pp. 400–404, May–June, 1998.     

Complexes of anion radicals of porphyrins with pyridine anions and reversibility of the intracomplex phototransfer of an electron

“S. I. Vavilov State Optical Institute”, All-Russia State Scientific Center, 12, Birzhevaya Liniya, St. Petersburg, 199034, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 62, No. 2, pp. 52–56, March–April, 1995     

Measurement of surface absorption in optical materials by the method of laser photothermal radiometry

The present work is devoted to the development of the method of laser photothermal radiometry with a view to increasing its spatial resolution over the depth of the specimen when surface layers of the substance of thickness about 1 μm or less are to be investigated. As an example, results of an investigation of radiation absorption in the surface layer of a lithium niobate crystal are presented. The absorption index measured at a wavelength of 1.08 μm was ∼0.6 cm⁻¹. “Polyus” Research Institute, 3, Vernadskii Ave., Moscow, 117342, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 82–84, January–February, 1997.     

Spectroscopic parameters of CHFCl2, CHClF2, C2F6, and C3F8 molecules

We investigate the IR spectra of solutions of R-21,-22,-116, and R-218 in liquid argon at 90K. The frequencies, half-widths, and absolute integral intensities of all of the absorption bands recorded are obtained and interpreted. Scientific-Research Institute of Physics, 1, Ul'yanovskaya Str., Petrodvorets, St. Petersburg, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 3, pp. 297–301, May–June, 1997.     

Compensating for birefringence in cylindrical active elements of solid-body lasers

We discuss a new method of compensation of thermally induced birefringence in cylindrical active elements of solid-body lasers; the method is based on the simultaneous use of two active elements with sign-opposite temperature gradients in the transverse direction. Basic features of the method are shown and schemes of its practical implementation are considered. To whom correspondence should be addressed. D. F. Ustinov Baltika State Technical University “VOENMEKH”, 1, 1st Krasnoarmeiskaya Str., St. Petersburg, 198005, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 4, pp. 573–577, July–August, 1999.