Vibrational energy storage in high pressure mixtures of diatomic molecules

Coherent anti-Stokes Raman scattering and spontaneous Raman scattering diagnostics of nonequilibrium plasmas and flows

“…These results exhibited markedly non-Boltzmann distribution of vibrational level populations, with first level vibrational temperature of T vib = 2500 K. More recently, spatially resolved measurements of nitrogen vibrational populations, N 2 (v = 0-8), have been performed in a short-lived afterglow of a microwave discharge in nitrogen [86], exhibiting a slowly evolving V-V pumped plateau in N 2 vibrational distribution. Spontaneous Raman measurements of vibrational level populations of three diatomic species, N 2 , O 2 , and CO, have been made in high-pressure (up to 1 bar) mixtures of these gases where CO in relatively low vibrational levels, v < 10, was vibrationally excited by resonance absorption of the CO laser radiation (10-20 W c.w [87][88][89]. ),…”

“…At these conditions, first level vibrational temperatures were T vib (CO) = 3500 K and T vib (N 2 ) = 2200, with CO exhibiting strikingly non-Boltzmann V-V pumped vibrational distribution (see figure 29). In these experiments, rotational/translational temperature was estimated from the rotational structure of N 2 S-branch Raman spectrum T rot = 420-640 K [88], and from the ratio of Q branch vibrational bands intensities in N 2 Raman spectra taken with CO pump laser turned on and off, T trans ≈ 500 K [87]. In optically pumped, steady-state CO/N 2 /O 2 mixtures, N 2 (v = 0-5), CO(v = 0-8), and O 2 (v = 0-12) have been detected (see figure 30).…”

Effect of electron density on shock wave propagation in optically pumped plasmas

“…The observed temperature increase is mainly due to the faster CO vibrational relaxation rate by vibrationvibration and vibration-translation energy transfer in collisions with O 2 molecules. 36 Although the actual radial temperature distribution in these experiments is not measured, it is also very unlikely to be affected by the O 2 additive since the transport coefficients of the gas mixture are insensitive to such small changes in chemical composition.…”

Pulsed CO laser and laser amplifier operating on oxygen containing gas mixtures

“…The rate of reaction (1) increases as vibrational quantum number V goes up, because the energy of ro-vibrational transitions of CO molecule at V~20 becomes equal to excitation energy of O 2 molecule within rotational-vibrational band of its vibrational transition 0→1 (∆E VJ ≈ 0). The influence of process (1) on stationary VDF of optically pumped CO molecules was discussed earlier, for example, in paper [18]. There is a transfer of vibrational energy to oxygen from the CO molecules during intermolecular exchange (1) at ∆E VJ ~ kT.…”

“…Our interest in studying EBSD CO laser AM with oxygen rich mixtures is connected with both research of singlet delta oxygen production in EBSD stabilized by adding of small amount of CO molecules [17] and with research of intermolecular VV exchange between CO and O 2 molecules [18,19]. It was shown in [19] that the SSG value on low vibrational transitions (V<15) in gas mixture CO:О 2 =1:20 was two times higher than in mixture CO:N 2 =1:20.…”