Investigation of the state-to-state rotational relaxation rate constants for carbon monoxide (CO) using infrared double resonance

Abstract

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Probing rotational relaxation in HBr (v=1) using double resonance spectroscopy

“…We note that atom-molecule R-T transfer models have been used successfully to treat diatom-diatom collisions in previous studies. 11,12,22 Of the many different parametric RET rate constant expressions that have been proposed, 13,14 we chose to examine the energy gap ͑EG͒, modified energy gap ͑MEG͒, statistical power exponential gap ͑SPEG͒, energy corrected sudden ͑ECS and ECS-EP͒, and the angular momentum and energy corrected sudden ͑AECS͒ models. [23][24][25] The EG model is simple and widely used.…”

Direct determination of state-to-state rotational energy transfer rate constants via a Raman-Raman double resonance technique: ortho-acetylene in v2=1 at 155 K

“…7 In these techniques, the pump process prepares the sample in a well de-fined initial rotational state, while the probe stage monitors the evolution of the population to other rotational states as a function of the delay ͑i.e., the number of collisions͒ between the pump and the probe. Several techniques have been used to prepare the state-selected sample, the most relevant being direct absorption of laser radiation, [8][9][10][11][12][13] the stimulated Raman effect [14][15][16][17] and stimulated emission pumping. 18 The literature shows many combinations of these pump methods with a variety of probe techniques: transient IR absorption, 8,9,13 laser-induced UV 14,19 or IR 8,9 fluorescence ͑LIF͒, resonant enhanced multiphoton ionization ͑REMPI͒, 17,15 coherent anti-Stokes Raman scattering ͑CARS͒, 20 etc.…”

Impulsive Collision Dynamics of CO Super Rotors from an Optical Centrifuge

“…[31] Recent molecular dynamics simulations by Steinitz et al provide an estimate for what the initial distribution might look like for N 2 and CO 2 in an opticalc entrifuge and how that distri-bution evolves. For CO initially prepared in J % 50, this rate indicates that rotational relaxation occurs on every collision.…”

“…This result is also consistent with previous double resonances tudies on Jspecific rotational relaxation in CO-COc ollisions that find thermalization is complete for CO J = 14 in seven hard-sphere collisions. [31] Recent molecular dynamics simulations by Steinitz et al provide an estimate for what the initial distribution might look like for N 2 and CO 2 in an opticalc entrifuge and how that distri-bution evolves. [9] Initially, ar elatively narrow asymmetricd istributiono fs uper rotor states is prepared with the opticalf ield on.…”