Transitions among the 3p<sup>2</sup>P states of sodium induced by collisions with helium

Reid, R. H. G.

doi:10.1088/0022-3700/6/10/018

Cited by 184 publications

(24 citation statements)

References 25 publications

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“…Then, the depolarization and polarization transfer rates of rovibartional molecular levels (vJ) have the same form as those developed for electronic atomic levels by Reid (1973) in the case of a structureless perturber ( j 2 = 0 like neutral Helium) and generalized by Kerkeni et al (2000) for j 2 0 cases (like neutral hydrogen). In fact, one should only carry out formal substitution between the electronic state of the perturbed atom and the rovibartional state of the molecule.…”

Section: Close Coupling Formulationmentioning

confidence: 87%

“…where the expression of the Grawert parameter B(JJ , g) is given in Reid (1973) for j 2 = 0 and Kerkeni et al (2000) when j 2 0, k B is the Boltzmann constant, µ the reduced mass of the system, E k J the collision energy, and k J the wave number. T and n H are the local temperature and the hydrogen perturber density respectively.…”

Section: Close Coupling Formulationmentioning

confidence: 99%

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Collisional depolarization of molecular lines. Application to the SiO+H isotropic collisions

Derouich¹

2006

A&A

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This paper reports the first theoretical study on the collisional depolarization and polarization transfer for rovibrational levels of diatomic molecules in the infinite-order-sudden approximation. As an application, we compute depolarization and polarization transfer rates for rotational levels J = 1,..., 99 within the vibrational quantum numbers v = 0, 1, 2, 3 of the SiO molecules in collisions with neutral hydrogen atoms for temperatures 400 ≤ T ≤ 1500 K. Analytical expressions of the collisional depolarizing rates of rovibrational levels as a function of local temperature and rotational number J are obtained. We note that the collisional depolarization rates decrease when J increases and that the fractional effect of the collisions on the J-levels can be characterized by a simple ratio. Especially for high J values, we find that alignment and population transfer rates between J to J + 1 inside the same vibrational number v are higher than the elastic depolarizing rates. This work might help to gain more understanding of the role of isotropic collisions in the formation of the very interesting polarized lines of C 2 and MgH observed in the solar photosphere.

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Section: Close Coupling Formulationmentioning

confidence: 87%

Section: Close Coupling Formulationmentioning

confidence: 99%

Collisional depolarization of molecular lines. Application to the SiO+H isotropic collisions

Derouich¹

2006

A&A

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“…The depolarisation cross section σ κ (J) is the sum of two terms: Λ κ (J) and the fine structure transfer cross sections J J σ(J → J ). Explicit expressions of the Λ κ (J) and σ κ (J → J) for J = 1/2 and 3/2 in terms of the Grawert parameters B (see Paper II for definition of B) were given by Reid (1973) and Kerkeni (2002) respectively. Expressions for J = 5/2 are given in Appendix A.…”

Section: Relaxation and Transfer Ratesmentioning

confidence: 99%

Depolarisation rates of Ca II s, p and d levels by isotropic collisions with hydrogen atoms

Kerkeni

Spielfiedel

Feautrier

2003

A&A

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Abstract.Multipole relaxation and transfer rates of the 4s 2 S, 3d 2 D and 4p 2 P states of Ca  due to isotropic collisions with neutral hydrogen atoms are calculated. Evaluation of these rates have been carried out using accurate ab initio potential energy curves. The collisional T-matrix elements required for these calculations have been evaluated in a quantum mechanical description including fine structure splitting. Analytical expressions of all the rates valid for 200 K ≤ T ≤ 10 000 K are given.

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“…is the Maxwellian distribution of relative velocities v at temperature T and coefficients B are a generalization of the Grawert factors introduced by Reid (1973). Here, µ is the reduced mass and k J is the wavenumber defined by k…”

Section: General Expression Of the Relaxation Constants And Of The Trmentioning

confidence: 99%

Depolarization rates of resonance lines of Mg, Ca, Sr and Na atoms by collisions with neutral hydrogen

Kerkeni

2002

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Abstract.Multipole relaxation and transfer rates due to isotropic collisions with neutral hydrogen atoms are calculated and a general expression for the hyperfine-structured levels are obtained. Evaluation of these rates has been carried out using accurate potential energy curves. The formulae given here for the depolarizing collisional rates should be useful for accurately modelling the complex linear polarization pattern of the Na  doublet in a complement to the ground state's depolarizing collisional rates which were presented in a previous paper (Kerkeni et al. 2000) hereafter referred to as Paper I. Similarly the depolarizing collisional rates of the Mg , Ca , Sr  resonance lines should be useful for polarization studies.

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Transitions among the 3p²P states of sodium induced by collisions with helium

Cited by 184 publications

References 25 publications

Collisional depolarization of molecular lines. Application to the SiO+H isotropic collisions

Collisional depolarization of molecular lines. Application to the SiO+H isotropic collisions

Depolarisation rates of Ca II s, p and d levels by isotropic collisions with hydrogen atoms

Depolarization rates of resonance lines of Mg, Ca, Sr and Na atoms by collisions with neutral hydrogen

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Transitions among the 3p2P states of sodium induced by collisions with helium

Cited by 184 publications

References 25 publications

Collisional depolarization of molecular lines. Application to the SiO+H isotropic collisions

Collisional depolarization of molecular lines. Application to the SiO+H isotropic collisions

Depolarisation rates of Ca II s, p and d levels by isotropic collisions with hydrogen atoms

Depolarization rates of resonance lines of Mg, Ca, Sr and Na atoms by collisions with neutral hydrogen

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Transitions among the 3p²P states of sodium induced by collisions with helium