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Using multidimensional particle-in-cell simulations, we show that an electron beam with a huge space charge can be accelerated to high energies by irradiating the edge of a solid density target with an intense femtosecond laser pulse at parallel incidence. The process of energy gain of each electron is divided into two parts: the transverse laser field and the longitudinal field of the excited surface plasma wave (SPW). It is shown that the longitudinal field of the SPW dominates the acceleration of the major part of electrons. This process leads to generation of a highly collimated electron beam with a huge space charge.

The HITRAN database is a compilation of molecular spectroscopic parameters. It was established in the early 1970s and is used by various computer codes to predict and simulate the transmission and emission of light in gaseous media (with an emphasis on terrestrial and planetary atmospheres). The HITRAN com- pilation is composed of five major components: the line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, experimental infrared absorption cross-sections (for molecules where it is not yet feasible for representation in a line-by-line form), collision-induced absorption data, aerosol indices of refraction, and general tables (including partition sums) that apply globally to the data. This paper describes the contents of the 2020 quadrennial edition of HITRAN. The HITRAN2020 edition takes advantage of recent experimental and theoretical data that were meticulously validated, in particu- lar, against laboratory and atmospheric spectra. The new edition replaces the previous HITRAN edition of 2016 (including its updates during the intervening years). All five components of HITRAN have undergone major updates. In particular, the extent of the updates in the HITRAN2020 edition range from updating a few lines of specific molecules to complete replace- ments of the lists, and also the introduction of additional isotopologues and new (to HITRAN) molecules: SO, CH 3 F, GeH 4 , CS 2 , CH 3 I and NF 3 . Many new vibrational bands were added, extending the spectral cov- erage and completeness of the line lists. Also, the accuracy of the parameters for major atmospheric absorbers has been increased substantially, often featuring sub-percent uncertainties. Broadening param- eters associated with the ambient pressure of water vapor were introduced to HITRAN for the first time and are now available for several molecules. The HITRAN2020 edition continues to take advantage of the relational structure and efficient interface available at www.hitran.org and the HITRAN Application Programming Interface (HAPI). The functionality of both tools has been extended for the new edition.

We present the results of the aberration correction of laser radiation wavefront using a dynamic method for determining the reference wavefront. The method, which is based on the processing of synchronously obtained data on the near- and far-field zones, significantly improves the focusing quality with active wavefront correction, especially under conditions of dynamic aberrations. An increase in the Strehl number S from 0.7 to 0.86 is demonstrated when a beam 18 cm in diameter is focused by an F/2.5 parabolic mirror.

A method for measuring the intensity of focused high-power laser pulses based on numerical simulation of high-harmonic generation in the laser peeler regime is proposed. The dependence of the efficiency of high-harmonic generation on the laser pulse intensity and the spatial parameters during interaction with solid targets is studied numerically. The simulation clearly shows that the amplitude of the generated harmonics depends on the laser pulse parameters. The proposed method is simpler than similar intensity measurement techniques and does not require complex preparation.

The luminescent and optical properties of materials based on zirconium(IV) oxide grown by crystallization of ZrO2 melts with 0, 2.0, 2.5, 2.8, and 3.7 mol % of Y2O3 are studied. Using Raman spectroscopy, it is found that this material with the Y2O3 concentration below 2 mol % is mainly a monoclinic ZrO2 phase. The photoluminescence spectra of these crystals contain a blue–green band peaking at an energy of 2.4 eV. This fact in combination with the specific features of the refractive index and absorption coefficient dispersions indicates the presence of high concentrations of oxygen vacancies and polyvacancies in the samples. At higher concentrations of Y2O3 in the mixture, the tetragonal ZrO2 modification becomes dominant in the materials under study and the blue–green luminescence intensity decreases. The experimental optical spectra are analyzed in comparison with the ab initio calculated spectra for ideal ZrO2 crystals in the cubic, tetragonal, and monoclinic phases.

The results of the operation of a wavefront correction system based on a deformable bimorph mirror of the PEARL subpetawatt laser facility are presented. An improvement in the quality of focusing of laser radiation, which led to an increase in the Strehl ratio from 0.3 to 0.6, is demonstrated. The features of the compensation for phase distortions of the wavefront in the case of a low pulse repetition rate, as well as the correct allowance for the noise of the CCD camera when calculating the Strehl ratio are investigated.

The optical properties and composition of thermal silicon oxide thin films processed in a hydrogen electron cyclotron resonance plasma have been studied by ellipsometry, quantum-chemical modeling, and photoluminescence spectroscopy. It has been found that the plasma processing of the films leads to their oxygen depletion and the formation of nonstoichiometric oxide SiOx

A bank of spectral line parameters of the principal isotopologue of the hydrogen sulfide molecule (H232S) is presented. The databank is based on the global simulation of line positions and intensities of this molecule within the method of effective operators. Parameters of the global effective Hamiltonian and effective dipole moment operator were derived from their fitting to the line positions and intensities observed, respectively, which were taken from the literature. The databank covers the 552.76–8424.32 cm−1 spectral range and includes the calculated values of the following spectral line parameters: line position and intensity, energies of lower and upper states, Einstein coefficient for the spontaneous emission, and the statistical weights of the lower and upper states. The intensity cutoff was chosen equal to 10−28 cm/molecule at T = 296 K. In total, the databank contains about 88 thousand lines. This databank is deployed on the website of V.E. Zuev Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences ( ftp://ftp.iao.ru/pub/H2S/ ).

Results of high-resolution molecular spectroscopy researches carried out at V.E. Zuev Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences (IAO SB RAS) during the last five years are briefly reviewed. We consider theoretical problems of vibrational-rotational spectra of basic molecules of atmospheric gases, spectral line profiles, problems of the atmospheric continuum absorption, and databases of molecular spectral characteristics in the gas phase. In the section of experimental researches, the main attention is paid to the Fourier spectroscopy results obtained with laser diodes as radiation sources, as well as with the Fourier spectrometer coupled to a multipass 30-meter cell with computer control of the optical path length under variations of gas temperature and pressure.

An alternative to the currently existing elemental basis for creating dynamic random-access memory and flash memory is memristor structures, i.e., two-electrode systems, whose operation is based on the resistance switching effect. In this paper, the results of studying the specific features of the production of memristor structures on the basis of copper sulfide as a promising material providing high-efficiency performance of the structures are reported. The process of copper sulfurization is considered. In this process, the surface region of the copper layer is transformed into sulfide, and the remaining part of the layer is used as the active electrode for the later formed memristor structure. It is shown that, as the concentrations of the initial chemical reagents is increased, the surface roughness of the sulfide layer significantly increases. The sulfide growth rate at optimal initial concentrations of the chemical reagents is ~30 nm/min. In studies of memristor structures, it is established that, as the copper sulfide thickness is increased, the ratio between the resistances in the low- and high-resistance states increases from 11.2 to 12.5. In the memristor structures formed in the study, the time of switching from the high- to low-resistance state is about 1.3 μs, whereas the time of switching from the low- to high-resistance state is 0.9 μs.

This paper describes the updates of the line positions and intensities for the carbon dioxide transitions in the 2020 edition of the HITRAN spectroscopic database. The new line list for all 12 naturally abundant isotopologues of carbon dioxide replaces the previous one from the HITRAN2016 edition. This update is primarily motivated by several issues related to deficient HITRAN2016 line positions and intensities that have been identified from laboratory and atmospheric spectra. Critical validation tests for the spectroscopic data were carried out to find problems caused by inaccuracies in CO2 line parameters. New sources of data were selected for the bands that were deemed problematic in the HITRAN2016 edition. Extra care was taken to retain the consistency in the data sources within the bands. The comparisons with the existing theoretical and semi-empirical databases (including ExoMol, NASA Ames, and CDSD-296) and with available experimental works were carried out. The HITRAN2020 database has been extended by including additional CO2 bands above 8000 cm−1, and magnetic dipole lines of CO2 were introduced in HITRAN for the first time by including the ν2+ν3 band in the 3.3-µm region. Although the main topic of this article is line positions and intensities, for consistency a recent algorithm for the line-shape parameters proposed in Hashemi et al. JQSRT (2020) was reapplied (after minor revisions) to the line list.

The use of the post-compression technique ensures gain in laser pulse peak power but at the same time degrades beam focusability due to the nonlinear wavefront distortions caused by a spatially nonuniform beam profile. In this paper a substantial focusability improvement of a post-compressed laser pulse by means of adaptive optics was demonstrated experimentally. The Strehl ratio increase from 0.16 to 0.43 was measured. Simulations showed that the peak intensity in this case reaches 0.52 of the theoretical limit.

This paper describes the 2020 release of the GEISA database (Gestion et Etude des Informations Spectroscopiques Atmosphériques: Management and Study of Atmospheric Spectroscopic Information), developed and maintained at LMD since 1974. GEISA is the reference database for several current or planned Thermal and Short-Wave InfraRed (TIR and SWIR) space missions IASI (Infrared Atmospheric Sounding Interferometer), IASI-NG (IASI New Generation), MicroCarb (Carbon Dioxide Monitoring Mission), Merlin (MEthane Remote sensing LIdar missioN). It is actually a compilation of three databases: the “line parameters database”, the “cross-section sub-database” and the “microphysical and optical properties of atmospheric aerosols sub-database”. The new edition concerns only the line parameters dataset, with significant updates and additions implemented using the best available spectroscopic data. The GEISA-2020 line parameters database involves 58 molecules (145 isotopic species) and contains 6,746,987 entries, in the spectral range from 10−6 to 35877 cm−1. In this version, 23 molecules have been updated (with 10 new isotopic species) and 6 new molecules have been added (HONO, COFCl, CH3F, CH3I, RuO4, H2C3H2 (isomer of C3H4)) corresponding to 15 isotopic species. The compilation can be accessed through the AERIS data and services center for the atmosphere website (https://geisa.aeris-data.fr/), with the development of a powerful graphical tool and convenient searching, filtering, and plotting of data using modern technologies (PostgreSQL database, REST API, VueJS, Plotly). Based on four examples (H2O, O3, O2 and SF6), this paper also shows how the LMD in house validation algorithm SPARTE (Spectroscopic Parameters And Radiative Transfer Evaluation) helps to evaluate, correct, reject or defer the input of new spectroscopic data into GEISA and this, thanks to iterations with researchers from different communities (spectroscopy, radiative transfer).

The optical properties of amorphous nonstoichiometric silicon oxide (SiOx) films of variable composition (x = 0.62–1.92) formed by plasma-enhanced chemical vapor deposition are studied in the spectral range of 1.12–4.96 eV. Spectral ellipsometry showed that the refractive index dispersion character allows one to assign the formed SiOx films to silicon-like films, dielectrics, or intermediate-conductivity-type films depending on the content of oxygen in the gas phase during synthesis. A model of the SiOx structure for ab initio calculations is proposed and describes well the experimental optical spectra. Ab initio calculations of the dependences of the SiOx refractive index and band gap on stoichiometry parameter x are performed.

This work describes the update of NO along with the incorporation of NO$_{2}$ and N$_{2}$O to the HITEMP database. Where appropriate, the HITRAN line lists for the same molecules have also been updated. This work brings the current number of molecules provided by HITEMP to seven. The initial line lists originating from \textit{ab initio} and semi-empirical methods for each molecule have been carefully validated against available observations and, where necessary, adjustments have been made to match observations. We anticipate this work will be applied to a variety of high-temperature environments including astronomical applications, combustion monitoring, and non-local thermodynamic equilibrium conditions.

The absorption spectrum of nitrous oxide around 1.56 µm has been recorded with Doppler limited resolution by a continuous-wave cavity ring-down spectrometer at room temperature using 15N-enriched samples. The typical sensitivity was at the level of 2 × 10−10 cm−1. In total, 3389 transitions were observed and ro-vibrationally assigned on the basis of the global effective Hamiltonian model for six nitrous oxide isotopologues (14N15N16O, 15N14N16O, 14N15N18O, 15N14N18O, 14N15N17O and 15N14N17O). The band-by-band analysis led to the determination of ro-vibrational parameters of 47 bands, 36 of them were newly observed, and the rotational analysis of 11 others were significantly extended and improved. New sets of the effective Hamiltonian parameters were determined for the 14N15N16O and 15N14N16O isotopic species.

In 2015 we published an atmospheric version, CDSD-296, of the carbon dioxide spectroscopic databank (CDSD) [Tashkun et al., JQSRT 152 (2015) 45–73]. Since that time many new experimental data have been published. Some CDSD data deficiencies have also been found. The purpose of the present work is to present a corrected and extended version of the databank. In particular, it includes more realistic uncertainties of the line positions and intensities. The databank contains the calculated line parameters (positions, intensities, air- and self-broadened half-widths and their coefficients of temperature dependence, as well as air- and self- pressure-induced shifts) of the twelve stable isotopic species of CO2. The reference temperature is 296 K, and the intensity cutoff is 10−30 cm−1/(molecule cm−2). More than 530,000 lines covering the 345–14,076 cm−1 spectral range are included in the databank. Comparisons of the new version of the CDSD with UCL, AMES and HITRAN2016 line lists are also given.

The absorption spectra of the mixture of SO2 and CO2 at different partial pressures of both gases have been recorded at room temperature in the 4 µm region using the Bruker IFS 125 HR FTIR spectrometer. The multispectrum fitting procedure has been applied to these spectra to recover the CO2-broadening and shift parameters of the sulfur dioxide spectral lines. The CO2 broadening and the pressure induced shift coefficients for 1422 and 116 lines of the ν1 + ν3 A-type band of 32S16O2 and 34S16O2, respectively, have been derived. Beside, these coefficients have been derived for 254 lines of the ν1 + ν2 + ν3 − ν2 hot band of 32S16O2. The rotational dependence of the values of these coefficients is discussed. The CO2 pressure induced shift coefficients for this molecule are published for the first time. The comparison of the obtained broadening coefficients to those published by other authors for one pure rotational line and for the lines of the ν1 B-type band is given.

Magnetic dipole and electric quadrupole absorption in carbon dioxide are addressed in details. The selection rules for both processes are presented. The equations for the line intensities are given. In the case of the quadrupole absorption the Herman-Wallis functions are derived. The results of the present paper were used in the analysis of the carbon dioxide absorption band at 3.3 µm in the atmosphere of Mars (Trokhimovskiy A, Perevalov V, Korablev O, Fedorova A, Olsen KS, Bertaux JL, Patrakeev A, Shakun A, Montmessin F, Lefevre F, Lukashevskaya A. First observation of the magnetic dipole CO2 absorption band at 3.3 µm in the atmosphere of Mars by ExoMars Trace Gas Orbiter ACS instrument. A&A 639, A142 (2020)). The retrieved from the Martian atmosphere spectra vibrational transition magnetic dipole moment for the 01111–00001 (ν2+ν3) band of 12C16O2 M 01111 ← 000001 | Δ l 2 | = 1 = 0.96 μ N (where μN is nuclear magneton) is one order of magnitude larger than the gyromagnetic ratio in the case of the rotation-induced magnetic dipole moment.

This paper presents an overview of the current status of the Virtual Atomic and Molecular Data Centre (VAMDC) e-infrastructure, including the current status of the VAMDC-connected (or to be connected) databases, updates on the latest technological development within the infrastructure and a presentation of some application tools that make use of the VAMDC e-infrastructure. We analyse the past 10 years of VAMDC development and operation, and assess their impact both on the field of atomic and molecular (A&amp, M) physics itself and on heterogeneous data management in international cooperation. The highly sophisticated VAMDC infrastructure and the related databases developed over this long term make them a perfect resource of sustainable data for future applications in many fields of research. However, we also discuss the current limitations that prevent VAMDC from becoming the main publishing platform and the main source of A&amp, M data for user communities, and present possible solutions under investigation by the consortium. Several user application examples are presented, illustrating the benefits of VAMDC in current research applications, which often need the A&amp, M data from more than one database. Finally, we present our vision for the future of VAMDC.

Optical properties of amorphous nonstoichiometric tantalum-oxide films of variable composition (TaOx, x = 1.94–2.51) in the spectral range of 1.12–4.96 eV, obtained by ion-beam sputtering-deposition of metallic tantalum at different partial oxygen pressures (0.53–9.09 × 10–3 Pa), have been investigated. It is shown by spectral ellipsometry that the character of dispersion of the absorption coefficient and refractive index in TaOx of variable composition suggests that light-absorbing films with dispersion similar to that in metals are formed at oxygen pressures in the growth chamber below 2.21 × 10–3 Pa, whereas transparent films with dielectric dispersion are formed at pressures above 2.81 × 10–3 Pa. According to the data of quantumchemical simulation, the absorption peak at a photon energy of 4.6 eV in TaOx observed in the absorptioncoefficient dispersion spectrum is due to oxygen vacancy. The peak in the Raman-scattering spectra of TaOx films with metallic dispersion at frequencies of 200–230 cm–1 is presumably related to tantalum nanoclusters.

The very weak absorption spectrum of natural CO2 near 1.74 µm (5702–5879 cm−1) is studied at high sensitivity. The investigated region corresponds to a transparency window of very weak opacity which is of particular interest for Venus. Very weak lines with intensity value as low as 10−30 cm/molecule at 296 K are detected by Cavity Ring Down Spectroscopy. On the basis of the predictions of effective Hamiltonian models, 1135 lines of six carbon dioxide isotopologues - 12C16O2, 13C16O2, 16O12C18O, 16O12C17O, 16O13C18O and 16O13C17O - were rovibrationnally assigned to 26 bands. The accurate spectroscopic parameters of 16 bands are determined from standard band-by-band analysis (typical rms deviations of the line positions are 8 × 10−4 cm−1). These newly observed bands include perturbed bands, weak hot bands and bands of minor isotopologues (in particular 16O12C18O in natural abundance) and provide critical validation tests for the most recent spectroscopic databases. The comparison to the Carbon Dioxide Spectroscopic Databank (CDSD), HITRAN2016 database and recent ab initio line lists is presented. Deficiencies are evidenced for some weak perpendicular bands of the HITRAN2016 list and identified as due to inaccurate CDSD intensities which were preferred to ab initio intensities. While Ames and UCL ab initio intensities are believed to be accurate within a few % for the strong unperturbed bands, the reported measurements allow testing important (>50%) differences between ab initio values of some weak perturbed bands.

The absorption spectra of the mixture of C2H2 and CO2 at different partial pressures of both gases have been recorded at room temperature in the 3 µm region using the Bruker IFS 125 HR FTIR spectrometer. The multispectrum fitting procedure has been applied to these spectra to recover the broadening and shift parameters of the acetylene spectral lines. The CO2 broadening and pressure induced shift coefficients for 119 lines of the ν3 and ν 2 + ( ν 4 + ν 5 ) + 0 bands of acetylene have been derived. The rotational dependence of the values of these coefficients is discussed. The comparison of the obtained coefficients to those published by other authors for the ν1 + ν3 and ( ν 4 + ν 5 ) + 0 bands is performed.

The absorption spectra of carbon dioxide have been recorded in the near infrared region from 10,000 to 10,300 cm -1 , using the Bruker IFS 125 HR Fourier transform spectrometer and a 30 m multipass cell with the White type optical system. The spectra were recorded at a spectral resolution of 0.03 cm − 1 , room temperature, a path length of 953.6 m and at two pressures of 294 and 523 mbar. The achieved sensitivity (noise equivalent absorption) at the level of k ν =1.38×10 − 10 cm −1 allowed detection of a number of new transitions with the intensity values down to 10 –29 cm/molecule at 296 K. Two bands 60014-00001 and 60015-00001 of 12 C 16 O 2 were detected for the first time. The line positions and intensities of these bands were determined using the Voigt profile as a line shape. The uncertainty of the line position determination was estimated to be about 0.003 cm -1 for the unblended lines with a high value of the signal-to-noise ratio. The uncertainty of the line intensity determination varies from 4% to 40% depending on the strength of the line and the extent of the line overlapping. The measured line intensities of the 60014-00001 and 60015-00001 bands together with those published earlier for the Δ P =15 series of transitions were used to fit the effective dipole moment parameters of this series. Here P =2 V 1 + V 2 +3 V 3 is the polyad number ( V i ( i =1,2,3) are the harmonic oscillators quantum numbers). The fitted parameters reproduce the measured line intensities within their experimental uncertainties. Using the effective Hamiltonian parameters published earlier and the fitted effective dipole moment parameters the line positions and intensities of the 6001 i -00001 ( i =1,2,3,4,5,6,7) bands have been calculated. A comparison of the measured line positions and intensities to those contained in the new version ( huang.seti.org ) AMES line list as well as in the High-T line list are given.

Total internal partition sums (TIPS) are reported for 166 isotopologues of 51 molecules important in planetary atmospheres. Molecules 1 to 50 are taken from the HITRAN2016 list, and, in some cases, additional isotopologues are considered for some of the molecules. Molecules 51–53 are C3H4, CH3, and CS2, respectively. TIPS are not reported for the O atom and CF4; thus, while there are 53 species in the list, data are reported for 51 molecules. The TIPS are determined by various methods from 1 K to a Tmax that ensures the TIPS reported have converged. These data are provided with HITRAN2016 and a new version of the TIPS code is available in both FORTRAN and python languages.

International audience

We present a high-resolution, high-temperature version of the Acetylene Spectroscopic Databank called ASD-1000. The databank contains the line parameters (position, intensity, Einstein coefficient for spontaneous emission, term value of the lower states, self- and air-broadening coefficients, temperature dependence exponents of the self- and air-broadening coefficients) of the principal isotopologue of C 2 H 2 . The reference temperature for line intensity is 296 K and the intensity cutoff is 10 −27 cm −1 /(molecule cm −2 ) at 1000 K. The databank has 33,890,981 entries and covers the 3–10,000 cm −1 spectral range. The databank is based on the global modeling of the line positions and intensities performed within the framework of the method of effective operators. The parameters of the effective Hamiltonian and the effective dipole moment operator have been fitted to the observed values of the line positions and intensities collected from the literature. The broadening coefficients as well as their temperature dependence exponents were calculated using the empirical equations. The databank is useful for studying high-temperature radiative properties of C 2 H 2 . ASD-1000 is freely accessible via the Internet site of V.E. Zuev Institute of Atmospheric Optics SB RAS ftp://ftp.iao.ru/pub/ASD1000/ .

We investigate oxygen-deficient crystalline zirconia using quantum-chemical simulation within the hybrid density functional theory. It was shown that the oxygen vacancy in ZrO 2 is the amphoteric defects and it can act as the electron and hole trap. The most energetically favorable spatial configuration of oxygen polyvacancies in ZrO 2 were calculated. It was found that each subsequent vacancy forms near the already existing one, and no more than 2 removed O atoms, related to Zr atom. The ability of oxygen polyvacancy to act as a conductive filament and to participate in the resistive switching is discussed.

Remote sensing experiments require high-accuracy, preferably sub-percent, line intensities and in response to this need we present computed room temperature line lists for six symmetric isotopologues of carbon dioxide: $^{13}$C$^{16}$O$_2$, $^{14}$C$^{16}$O$_2$, $^{12}$C$^{17}$O$_2$, $^{12}$C$^{18}$O$_2$, $^{13}$C$^{17}$O$_2$ and $^{13}$C$^{18}$O$_2$, covering the range 0-8000 \cm. Our calculation scheme is based on variational nuclear motion calculations and on a reliability analysis of the generated line intensities. Rotation-vibration wavefunctions and energy levels are computed using the DVR3D software suite and a high quality semi-empirical potential energy surface (PES), followed by computation of intensities using an \abinitio\ dipole moment surface (DMS). Four line lists are computed for each isotopologue to quantify sensitivity to minor distortions of the PES/DMS. Reliable lines are benchmarked against recent state-of-the-art measurements and against the HITRAN2012 database, supporting the claim that the majority of line intensities for strong bands are predicted with sub-percent accuracy. Accurate line positions are generated using an effective Hamiltonian. We recommend the use of these line lists for future remote sensing studies and their inclusion in databases.

In spite of being a greenhouse gas with a large global warming potential, the absorption spectrum of nitrous oxide in the near infrared is insufficiently characterized. In the present work, the spectral region near 1.74 µm (5696–5910 cm−1) is investigated by high sensitivity cavity ring down spectroscopy (CRDS). The noise level of the CRDS spectra corresponds to a typical minimum detectable absorption, αmin, below 10-10 cm−1. 3326 transitions are measured and rovibrationally assigned to 50 bands of five nitrous oxide isotopologues (14N216O, 14N15N16O, 15N14N16O, 14N218O and 14N217O) in natural isotopic abundance. The assigned weakest lines have an intensity below 10−28 cm/molecule. For comparison, only three 14N216O bands are included in the HITRAN database in the region, with a 2 × 10−25 cm/molecule intensity cut off. The rovibrational assignments were performed by comparison with predictions performed for each isotopologue in the frame of the effective operator approach. The overall quality of the predictions is satisfactory for line positions. Deviations larger than 0.1 cm−1 are nevertheless noted for 14N216O and 14N218O. The spectroscopic parameters of the upper level of the observed bands were derived from the standard band-by-band fit of the measured line positions. A significant number of bands were found to be perturbed by local rovibrational perturbations and in some cases, extra lines due to an intensity transfer could be assigned. The interaction mechanisms and the perturbers were univocally identified on the basis of the effective Hamiltonian model. In particular, interpolyad couplings were evidenced indicating that the polyad version of the effective Hamiltonian has to be extended to include Coriolis and interpolyad anharmonic interactions. No satisfactory modeling of the N2O line intensities is yet available in the region. The CRDS intensity values derived in this work provide a solid set of measurements for future semi-empirical intensity modeling in the region.

The design of ellipsoidal plasma mirrors (EPMs) for the PEARL laser facility is presented. The EPMs achieve a magnification of 0.32 in focal spot size, and the corresponding increase in focused intensity is expected to be about 8. Designing and implementing such focusing optics for short-pulse (

The room temperature absorption spectrum of 17O enriched carbon dioxide is investigated by high sensitivity cavity ring down spectroscopy (CRDS) between 5695 and 5850 cm−1. About 1100 lines are measured and assigned to 26 bands of the six 17O containing carbon dioxide isotopologues: 16O12C17O, 16O13C17O, 17O12C18O, 17O13C18O, 12C17O2 and 13C17O2. The set of observed lines are rovibrationnally assigned on the basis of the predictions of the effective Hamiltonian (EH) model. The observed bands belong to the ΔP = 8 and 9 series of transitions where P = 2 V1 + V2 + 3 V3 is the polyad number (Vi being the vibrational quantum numbers). They consist in 12 previously unobserved bands and 14 already-known bands, for which additional high J lines are assigned. Bands of the 12C17O2 and 13C17O2 isotopologues (two for each) are observed for the first time in this spectral interval. The spectroscopic parameters of the upper vibrational levels are determined from a band-by-band fit of the line positions (typical rms deviations are less than 0.001 cm−1). The comparison to the most recent carbon dioxide spectroscopic databases is presented. The reported data will be used to improve the modeling of the line positions of 17O containing carbon dioxide isotopologues.

The isotopic substitution relations for the effective dipole moment parameters of a heterogenic diatomic molecule have been derived. These equations are applied to the calculations of the line intensities of the minor carbon monoxide isotopologues, including the radioactive ones. The comparisons of the calculated line intensities of the minor isotopologues to those observed and to those earlier calculated are given. These comparisons show that the used method has potential of predicting intensities of the minor isotopologues of carbon monoxide within 2-10%. The comparison of our calculated line intensities for the radioactive isotopologues of the carbon monoxide molecule to those from (G. Li, I.E. Gordon, L.S. Rothman, Y. Tan, S.-M. Hu, S. Kassi, A. Campargue, E.S. Medvedev, Astrophys. J. Suppl. Ser. 216 (2015) 16) is also given.

The 1.74 µm spectral region corresponds to a very weak absorption interval of carbon dioxide (or “transparency window”) of particular importance to sound the deep atmosphere and the surface of Venus. In the present work, we extend the characterization of this spectral interval by the study of the 13CO2 isotopologues by high sensitivity cavity ring down spectroscopy (CRDS) with a highly enriched 13C sample. Indeed, in spite of their low natural abundances, the 13C minor isotopologues (in particular 16O13C18O with natural abundance less than 4.5 × 10−5) contribute importantly to the small residual opacity. In the studied 5694–5851 cm−1 spectral interval about 980 lines with intensity values as low as a few 10−30 cm/molecule at 296 K were detected. On the basis of the predictions of effective Hamiltonian models, the measured CO2 transitions were assigned to six isotopologues: 12C16O2, 13C16O2, 16O12C18O, 16O13C18O, 16O13C17O and 13C18O2. A total of 20 bands were assigned to the 13C isotopologues. Six of them are newly reported while the set of observed rotational transitions is enlarged for the others. The spectroscopic parameters of nineteen 13CO2 bands are determined from standard band-by-band analysis (typical rms deviations of the line positions are 8 × 10−4 cm−1). The new data show an overall good agreement with the Carbon Dioxide Spectroscopic Databank (CDSD-296), HITRAN2016 database and ab initio CO2 line lists. The previously identified issue related to the mixing of line intensities with CDSD or ab initio origins in the HITRAN database is illustrated by the 41104-00001 band of 13C16O2. A general discussion of the bands affected by this issue in the HITRAN2016 list is included.

The spectra of carbon dioxide in the 3.3 µm region were recorded at three pressures using Bruker IFS 125 HR Fourier transform spectrometer and a 30 m base multipass gas cell of V.E. Zuev Institute of Atmospheric Optics SB RAS. Several lines of the 01111–00001 (ν2 + ν3) magnetic dipole band of 12C16O2 were detected and their line intensities were measured. The vibrational transition magnetic dipole moment was fitted to the observed line intensities. The fitted value of the vibrational transition magnetic dipole moment of 0.71(1)µN is substantially smaller than the value of 0.96µN obtained in the result of the analysis of the Martian atmosphere spectra (here µN is the nuclear magneton). Using the known set of the effective Hamiltonian parameters and fitted value of the vibrational transition magnetic dipole moment the list of the line parameters of this band was generated for the HITRAN database. In addition the line intensities of the R-branch of the electric dipole 01111–00001 band of the 16O12C18O isotopologue were measured for the first time.

We present a high-resolution, high-temperature version of the Nitrogen Dioxide Spectroscopic Databank called NDSD-1000. The databank contains the line parameters (positions, intensities, self- and air-broadening coefficients, exponents of the temperature dependence of self- and air-broadening coefficients) of the principal isotopologue of NO2. The reference temperature for line intensity is 296 K and the intensity cutoff is 10−25 cm−1/molecule cm−2 at 1000 K. The broadening parameters are presented for two reference temperatures 296 K and 1000 K. The databank has 1,046,808 entries, covers five spectral regions in the 466–4776 cm−1 spectral range and is designed for temperatures up to 1000 K. The databank is based on the global modeling of the line positions and intensities performed within the framework of the method of effective operators. The parameters of the effective Hamiltonian and the effective dipole moment operator have been fitted to the observed values of the line positions and intensities collected from the literature. The broadening coefficients as well as the temperature exponents are calculated using the semi-empirical approach. The databank is useful for studying high-temperature radiative properties of NO2. NDSD-1000 is freely accessible via the internet site of V.E. Zuev Institute of Atmospheric Optics SB RAS ftp://ftp.iao.ru/pub/NDSD/ .

We present a high-temperature version, NOSD-1000, of the nitrous oxide spectroscopic databank. The databank contains the line parameters (positions, intensities, air- and self-broadened half-widths and coefficients of temperature dependence of air- and self-broadened half-widths) of the most abundant isotopologue 14N216O of the nitrous oxide molecule. The reference temperature is Tref=1000 K and the intensity cutoff is Icut=10−25 cm−1/(molecule cm−2). More than 1.4 million lines covering the 260–8310 cm−1 spectral range are included in NOSD-1000. The databank has been generated within the framework of the method of effective operators and based on the global fittings of spectroscopic parameters (parameters of the effective Hamiltonian and effective dipole moment operators) to observed data collected from the literature. Line-by-line simulation of a medium-resolution high-temperature (T=873 K) spectrum has been performed in order to validate the databank. NOSD-1000 is freely accessible via the Internet.

The global modeling of both line positions and intensities of the acetylene molecule in the 50–9900 cm−1 region has been performed using the effective operators approach. The parameters of the polyad model of effective Hamiltonian have been fitted to the line positions collected from the literature. The used polyad model of effective Hamiltonian takes into account the centrifugal distortion, rotational and vibrational l -doubling terms and both anharmonic and Coriolis resonance interaction operators arising due to the approximate relations between the harmonic frequencies: ω1≈ω3≈5ω4≈5ω5 and ω2≈3ω4≈3ω5. The dimensionless weighted standard deviation of the fit is 2.8. The fitted set of 237 effective Hamiltonian parameters allowed reproducing 24,991 measured line positions of 494 bands with a root mean squares deviation 0.0037 cm−1. The eigenfunctions of the effective Hamiltonian corresponding to the fitted set of parameters were used to fit the observed line intensities collected from the literature for 15 series of transitions: ΔP = 0-13,15, where P=5V1+5V3 +3V2+V4+V5 is the polyad number (Vi are the principal vibrational quantum numbers). The fitted sets of the effective dipole moment parameters reproduce the observed line intensities within their experimental uncertainties 2–20%.

The global modeling of 15N216O line positions in the 4–12,516 cm−1 region has been performed using the polyad model of effective Hamiltonian. The effective Hamiltonian parameters were fitted to the line positions collected from an exhaustive review of the literature. The dimensionless weighted standard deviation of the fit is 1.31. The fitted set of 109 parameters allowed reproducing more than 18,000 measured line positions with an RMS value of 0.001 cm−1. A line list was calculated for a reference temperature 296 K, natural abundance (1.32×10−5), and an intensity cutoff 10−30 cm/molecule. The line list is based on the fitted set of the effective Hamiltonian parameters for 15N216O obtained in this work and the effective dipole moment parameters of the 15N216O and 14N216O isotopologues. Accurate values of the 15N216O total partition function are also given.

The absorption spectrum of nitrous oxide (N 2 O) in natural isotopic abundance has been recorded near 1.22 µm by Cavity Ring Down Spectroscopy using an External Cavity Diode Laser (ECDL) as light source. The room temperature recordings were performed at a pressure of 10.0 Torr in the 7915–8334 cm −1 spectral range (1.26–1.19 μm). The typical noise equivalent absorption of the spectra, on the order of α min ~ 2×10 −11 cm −1 , allowed for the detection of lines with intensities on the order of 5×10 −29 cm/molecule. More than 3300 transitions belonging to 64 bands of five nitrous oxide isotopologues ( 14 N 2 16 O, 14 N 15 N 16 O, 15 N 14 N 16 O, 14 N 2 18 O and 14 N 2 17 O) have been rovibrationally assigned on the basis of the predictions of the effective Hamiltonian models developed for each isotopologue. For comparison, only 13 bands were previously measured by Fourier Transform spectroscopy in the studied region. All identified bands belong to the Δ P =13 and 14 series of transitions, where P= 2 V 1 + V 2 +4 V 3 is the polyad number ( V i are vibrational quantum numbers). The line positions and intensities are provided for all assigned lines. The maximum deviations between the measured position values and those predicted by the effective Hamiltonian models are about 0.2 cm −1 for the main isotopologue but reach values larger than 1 cm −1 for the less abundant minor isotopologues. The band-by-band analysis led to the determination of the rovibrational parameters of a total of 62 bands. The typical rms value of the ( ν obs − ν fit ) differences is 0.7×10 −3 cm −1 . Among the 62 bands, 49 are newly measured, for 13 others the rotational analysis is significantly improved and extended. A few resonance perturbations due to intra- and inter-polyad couplings are identified and discussed.