Term Values and Molecular Parameters for CH and CH<sup>+</sup>

Botterud, I; Lofthus, Alf; Veseth, L.

doi:10.1088/0031-8949/8/5/007

Cited by 56 publications

(13 citation statements)

References 14 publications

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“…The main reason for the discrepancy between the data for the other systems probably lies with systematic uncertainties in determining the absorption baselines at low optical densities. Combining the results for all three transitions gives a SO coupling constant of A Π ) 21 ( 1 cm -1 (reduced by ∼11 cm -1 from the gasphase value 17 ) and an orbital reduction factor of κ ) 0.26 ( 0.03.…”

Section: Discussionmentioning

confidence: 91%

“…)] (40) determining M 1 at low temperatures in the presence of a very much larger M 0 , but the data in Figure 1 give A ∆ ) 6 ( 2 cm -1 . In contrast, A ∆ ) -1.1 ( 0.2 cm -1 for CH in the gas phase, 17 which indicates that the matrix imposes a substantial external-atom SO effect on the A 2 ∆ states. M 0 and M 1 yield no information about V ∆ , the CF splitting of the A 2 ∆ term.…”

Section: Discussionmentioning

confidence: 99%

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Magnetic Circular Dichroism of the CH Radical in an Argon Matrix

Langford

Williamson

1998

J. Phys. Chem. A

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Magnetic circular dichroism (MCD) and absorption spectra are reported for the CH (methylidyne or methyne) free radical isolated in an Ar matrix (CH/Ar) over the temperature range 1.4-15.9 K and the magnetic-field range 0-4 T. Data for the A 2 ∆ r X 2 Π, B 2 Σr X 2 Π, and C 2 Σ + r X 2 Π band systems indicate a substantial quenching of the orbital angular momentum of the CH ground-state term. This is interpreted as being a consequence of crystal-field interactions involving atoms of the host lattice. Analysis of the zeroth moments of the spectra yields an empirical spin-orbit coupling constant A Π ) 21 ( 1 cm -1 and orbital reduction factor κ ) 0.26 ( 0.03, corresponding to a crystal-field splitting of V Π ) 78 ( 14 cm -1 for the X 2 Π term. For the A 2 ∆ excited-state term, the first MCD moments give A ∆ ) 5 ( 1 cm -1 , and an upper limit of V ∆ j 15 cm -1 is estimated from the dispersion of the MCD.

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Section: Discussionmentioning

confidence: 91%

Section: Discussionmentioning

confidence: 99%

Magnetic Circular Dichroism of the CH Radical in an Argon Matrix

Langford

Williamson

1998

J. Phys. Chem. A

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“…Extensive spectroscopic studies have been made of the ground state 78 and the lowest three excited states [79][80][81][82][83][84][85][86][87] partly because of its importance in astrophysics and chemistry. [88][89][90][91][92][93][94] Two excited state potential curves look promising for cooling CH: C 2 S + and 2 D as both have strongly fluorescing transitions to the ground state.…”

Section: Laser Cooling Of Chmentioning

confidence: 99%

Prospects for ultracold carbon via charge exchange reactions and laser cooled carbides

Wells

Lane

2011

Phys. Chem. Chem. Phys.

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Strategies to produce an ultracold sample of carbon atoms are explored and assessed with the help of quantum chemistry. After a brief discussion of the experimental difficulties using conventional methods, two strategies are investigated. The first attempts to exploit charge exchange reactions between ultracold metal atoms and sympathetically cooled C(+) ions. Ab initio calculations including electron correlation have been conducted on the molecular ions [LiC](+) and [BeC](+) to determine whether alkali or alkaline earth metals are a suitable buffer gas for the formation of C atoms but strong spontaneous radiative charge exchange ensure they are not ideal. The second technique involves the stimulated production of ultracold C atoms from a gas of laser cooled carbides. Calculations on LiC suggest that the alkali carbides are not suitable but the CH radical is a possible laser cooling candidate thanks to very favourable Frank-Condon factors. A scheme based on a four pulse STIRAP excitation pathway to a Feshbach resonance is outlined for the production of atomic fragments with near zero centre of mass velocity.

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“…If a plasma is optically thin, then the photon flux I(p, q) of a transition from state p to state q is given by the expression (12) where I(p, q) is in units of photon flux per unit area per unit solid angle, n(p) is the density of the emitting species p, A(p, q) is the transition probability, and integration is over the observed depth of the plasma, c~9~…”

Section: Excited Argon Neutral Densities Estimated From Relative Linementioning

confidence: 99%

Particle densities and non-equilibrium in a low-pressure argon plasma jet

Fusselman

Yasuda

1994

Plasma Chem Plasma Process

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Plasma diagnostic techniques have been employed to determine particle densities and temperatures in a low-pressure argon plasma jet generated by a cascade arc. These measurements allow characterization of the extent to which the plasma jet deviates from thermodynamic equilibrium and provide a basis for predicting how reactive gases will interact with the excited and ionized species in the plasma jet. It was found that the distribution of atomic states in the plasma jet is not adequately described by either local thermodynamic equilibrium ( L TE) or partial local thermodynamic equilibrium (pLTE), and the jet was optically thick for 3p~4s transitions across the jet radius. Excited argon neutrals outnumber ions by a large ratio,and dominate subsequent dissociation/excitation phenomena. The rate of methane destruction in the plasma jet shows that estimates for particle densities, temperature, and jet velocity are self-consistent.

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Term Values and Molecular Parameters for CH and CH⁺

Abstract: Term values and molecular parameters for C H and CH+. I. Botterud, A.

Cited by 56 publications

References 14 publications

Magnetic Circular Dichroism of the CH Radical in an Argon Matrix

Magnetic Circular Dichroism of the CH Radical in an Argon Matrix

Prospects for ultracold carbon via charge exchange reactions and laser cooled carbides

Particle densities and non-equilibrium in a low-pressure argon plasma jet

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Term Values and Molecular Parameters for CH and CH+

Abstract: Term values and molecular parameters for C H and CH+. I. Botterud, A.

Cited by 56 publications

References 14 publications

Magnetic Circular Dichroism of the CH Radical in an Argon Matrix

Magnetic Circular Dichroism of the CH Radical in an Argon Matrix

Prospects for ultracold carbon via charge exchange reactions and laser cooled carbides

Particle densities and non-equilibrium in a low-pressure argon plasma jet

Contact Info

Product

Resources

About

Term Values and Molecular Parameters for CH and CH⁺