Rotational temperature
View article
Time evolution of vibrational temperatures in a CO<sub>2</sub>glow discharge measured with infrared absorption spectroscopy Open
Vibrational temperatures of CO2 are studied in a pulsed glow discharge by means of time-resolved in situ Fourier transform infrared spectroscopy, with a 10 μs temporal resolution. A method to analyze the infrared transmittance through vibr…
View article
The importance of thermal dissociation in CO<sub>2</sub> microwave discharges investigated by power pulsing and rotational Raman scattering Open
\n Contains fulltext :\n 216008.pdf (Publisher’s version ) (Open Access)\n
View article
Spectroscopic study of CO2 and CO2–N2 mixture plasma using dielectric barrier discharge Open
Nowadays, increasing concentration of CO2 in the atmosphere is a major threat for the environment and is a main reason for global warming. Variation in gas temperature and dissociation of CO2 into its by-products (CO and O) in a home-made …
View article
The rotational excitation of the HCN and HNC molecules by H2 revisited Open
International audience
View article
Rotational relaxation of HCO+ and DCO+ by collision with H2 Open
The HCO+ and DCO+ molecules are commonly used as tracers in the interstellar medium. Therefore, accurate rotational rate coefficients of these systems with He and H2 are crucial in non-local thermal equilibrium models. We determine in this…
View article
Effect of plasma on gas flow and air concentration in the effluent of a pulsed cold atmospheric pressure helium plasma jet Open
In this work, we report on the flow effects induced by a nanosecond pulsed helium cold atmospheric pressure plasma jet impinging on a glass substrate. Gas temperature measurements have been performed using optical emission spectroscopy inc…
View article
Deuterated methanol on a solar system scale around the HH212 protostar Open
Context. Deuterium fractionation is a valuable tool for understanding the chemical evolution during the process that leads to the formation of a Sun-like planetary system. Aims. Methanol is thought to be mainly formed during the prestellar…
View article
A rotational Raman study under non-thermal conditions in a pulsed CO<sub>2</sub>glow discharge Open
The implementation of in situ rotational Raman spectroscopy is realized for a pulsed glow discharge in CO2 in the mbar range and is used to study the rotational temperature and molecular number densities of CO2, CO, and O2. The polarizabil…
View article
Burning velocity measurement of lean methane-air flames in a new nanosecond DBD microplasma burner platform Open
This paper presents the initial characterization of a new burner design to study the effect of non-thermal plasma discharge on combustion characteristics at atmospheric pressure. The burner allows stabilizing an inverted cone flame in a mi…
View article
Discovery of two new interstellar molecules with QUIJOTE: HCCCHCCC and HCCCCS Open
We report on the discovery of two new molecules, HCCCHCCC and HCCCCS, towards the starless core TMC-1 in the Taurus region from the QUIJOTE line survey in the 31.1–50.2 GHz frequency range. We identify a total of twenty-nine lines of HCCCH…
View article
Analysis of 24 years of mesopause region OH rotational temperature observations at Davis, Antarctica – Part 1: long-term trends Open
The long-term trend, solar cycle response, and residual variability in 24 years of hydroxyl nightglow rotational temperatures above Davis research station, Antarctica (68∘ S, 78∘ E) are reported. Hydroxyl rotational temperatures are a laye…
View article
Single-electrode He microplasma jets driven by nanosecond voltage pulses Open
Excited by 5 ns, 8 kV voltage pulses, a 260 μm-diameter, 8 mm long helium plasma jet was generated with a single-electrode configuration in ambient air. Application of fast high voltage pulses (≥1012 V s−1) resulted in rapid acceleration o…
View article
Rotational transitions of C3N− induced by collision with H2 Open
International audience
View article
Water and interstellar complex organics associated with the HH 212 protostellar disc Open
Context. The unprecedented combination of high-sensitivity and high angular resolution provided by the ALMA interferometer allows us to shed light on the processes leading to the formation of the jet-disc system associated with a Sun-like …
View article
Cooling of a Zero-Nuclear-Spin Molecular Ion to a Selected Rotational State Open
We demonstrate rotational cooling of the silicon monoxide cation via optical pumping by a spectrally filtered broadband laser. Compared with diatomic hydrides, SiO^{+} is more challenging to cool because of its smaller rotational interval.…
View article
Rotationally inelastic collisions of SiO with H2 Open
International audience
View article
Variability of the Brunt–Väisälä frequency at the OH <sup>∗</sup> -airglow layer height at low and midlatitudes Open
Airglow spectrometers, as they are operated within the Network for the Detection of Mesospheric Change (NDMC; https://ndmc.dlr.de, last access: 1 November 2020), for example, allow the derivation of rotational temperatures which are equiva…
View article
Collisional Quenching of Highly Excited H<sub>2</sub> due to H<sub>2</sub> Collisions Open
Rate coefficients for pure rotational quenching in H 2 ( ν 1 = 0, j 1 ) + H 2 ( ν 2 = 0, j 2 ) collisions from initial levels of j 1 = 2–31 ( j 2 = 0 or 1) to all lower rotational levels are presented. We carried out extensive quantum mech…
View article
Time-Resolved Kinetic Chirped-Pulse Rotational Spectroscopy in a Room-Temperature Flow Reactor Open
Chirped-pulse Fourier transform millimeter-wave spectroscopy is a potentially powerful tool for studying chemical reaction dynamics and kinetics. Branching ratios of multiple reaction products and intermediates can be measured with unprece…
View article
High-temperature hypersonic Laval nozzle for non-LTE cavity ringdown spectroscopy Open
A small dimension Laval nozzle connected to a compact high enthalpy source equipped with cavity ringdown spectroscopy (CRDS) is used to produce vibrationally hot and rotationally cold high-resolution infrared spectra of polyatomic molecule…
View article
Molecular gas thermometry on acetylene using dual-comb spectroscopy: analysis of rotational energy distribution Open
We propose and demonstrate a novel method for temperature determination using dual-comb spectroscopy and a novel analysis technique, “Rotational-state Distribution Thermometry: RDT.” We obtained the spectral profile of a vibration–rotation…
View article
Measuring the rotational temperature and pump intensity in molecular alignment experiments via high harmonic generation Open
We demonstrate a method to simultaneously measure the rotational temperature and pump intensity in laser-induced molecular alignment by the time-resolved high harmonic spectroscopy (HHS). It relies on the sensitive dependence of the arisin…
View article
GATOS: missing molecular gas in the outflow of NGC 5728 revealed by JWST Open
The ionisation cones of NGC 5728 have a deficit of molecular gas based on millimetre observations of CO (2-1) emission. Although photoionisation from the active nucleus may lead to suppression of this transition, warm molecular gas can sti…
View article
Discovery of two metallic cyanoacetylides in IRC +10216: HMgCCCN and NaCCCN Open
We report on the detection of a series of six lines in the ultra-deep Q -band integration towards IRC +10216 carried out with the Yebes 40 m telescope, which are in harmonic relation with integer quantum numbers J u from 12 to 18. After a …
View article
Time-dependent molecular emission in IRC + 10216 Open
Context . The variability in IRC+10216, the envelope of the asymptotic giant branch (AGB) star CW Leo, has attracted increasing attention in recent years. Studying the details of this variability in the molecular emission required a system…
View article
Microwave-enhanced laser-induced air plasma at atmospheric pressure Open
This paper investigated how microwaves affect the temperature of laser-generated air plasma. The air breakdown threshold was experimentally characterized by focusing the 1064 nm YAG laser on varied condensing lens focal lengths. Increase i…
View article
Bright, continuous beams of cold free radicals Open
We demonstrate a cryogenic buffer gas-cooled molecular beam source capable of\nproducing bright, continuous beams of cold and slow free radicals via laser\nablation over durations of up to 60~seconds. The source design uses a closed\nliqui…
View article
Rotational energy transfer in collisions between CO and Ar at temperatures from 293 to 30 K Open
Experimental measurements and theoretical calculations are reported for rotational energy transfer in the Ar-CO system. Experiments were performed in cold uniform supersonic flows of Ar, using an infrared – vacuum ultraviolet double resona…
View article
Pure-rotational H2 thermometry by ultrabroadband coherent anti-Stokes Raman spectroscopy Open
Coherent anti-Stokes Raman spectroscopy (CARS) is a sensitive technique for probing highly luminous flames in combustion applications to determine temperatures and species concentrations. CARS thermometry has been demonstrated for the vibr…
View article
Broad-band high-resolution rotational spectroscopy for laboratory astrophysics Open
We present a new experimental set-up devoted to the study of gas phase molecules and processes using broad-band high spectral resolution rotational spectroscopy. A reactor chamber is equipped with radio receivers similar to those used by r…