The alignment of atomic states as the result of collisions with a beam of slow charged particles is investigated. The problem of the collisional reorientation of atomic moments is solved by numerical integration of the equations of the impact parameter method taking into account charge--quadrupole interaction. Calculations are made of the alignment of the /sup 2/P/sub 3//sub ///sub 2/ levels of alkali atoms populated by collisions with selective excitation of the /sup 2/P/sub 1//sub ///sub 2/ level. The linear polarization of light emitted by the /sup 2/P/sub 3//sub ///sub 2/ level attains some tens of percents and corresponds to the predominance of polarization in directions perpendicular to the beam. The efficiency of the resulting alignment depends on the volume density but not on the velocity of the beam of charged particles. Thus the slow drift of ions (and electrons) in a gas-discharge plasma can compete with alignment as the result of fluxes of charged particles. We shall formulate the sum rules for anisotropic collisional relaxation of atomic polarization moments. It follows from these that for the appearance of alignment in intramultiplet mixing under the action of anisotropic collisions we require a nonuniform population of multiplet levels that differs from the more » ratio of their statistical weights. « lessThe alignment of atomic states as the result of collisions with a beam of slow charged particles is investigated. The problem of the collisional reorientation of atomic moments is solved by numerical integration of the equations of the impact parameter method taking into account charge--quadrupole interaction. Calculations are made of the alignment of the /sup 2/P/sub 3//sub ///sub 2/ levels of alkali atoms populated by collisions with selective excitation of the /sup 2/P/sub 1//sub ///sub 2/ level. The linear polarization of light emitted by the /sup 2/P/sub 3//sub ///sub 2/ level attains some tens of percents and corresponds to the predominance of polarization in directions perpendicular to the beam. The efficiency of the resulting alignment depends on the volume density but not on the velocity of the beam of charged particles. Thus the slow drift of ions (and electrons) in a gas-discharge plasma can compete with alignment as the result of fluxes of charged particles. We shall formulate the sum rules for anisotropic collisional relaxation of atomic polarization moments. It follows from these that for the appearance of alignment in intramultiplet mixing under the action of anisotropic collisions we require a nonuniform population of multiplet levels that differs from the more » ratio of their statistical weights. « less

Optics and SpectroscopyAug 1, 19840 citations

Transitions in Two-Level Systems in Atomic Collisions

E. Duman

peacJan 1, 19750 citations

Observation of three-body collisional transfer between atomic levels

Martin A. Harris, James Floyd Kelly, Alan C. Gallagher

Collisional $J$ -mixing rates between the $J=0, 1, 2$ states of the $\mathrm{Sr}(5^{3}P_{J})$ multiplet have been measured in the presence of rare-gas perturbers. For Kr and Xe pressures above 100 Torr, the rates are dominated by a component which is quadratic in pressure. We believe this very unusual behavior is brought about by the simultaneous interaction of a Sr atom with two perturbers and not by excimer formation.Collisional $J$-mixing rates between the $J=0, 1, 2$ states of the $\mathrm{Sr}(5^{3}P_{J})$ multiplet have been measured in the presence of rare-gas perturbers. For Kr and Xe pressures above 100 Torr, the rates are dominated by a component which is quadratic in pressure. We believe this very unusual behavior is brought about by the simultaneous interaction of a Sr atom with two perturbers and not by excimer formation.

Physical Review AAug 1, 198712 citations

Collisional

J

-mixing rates between the

J=0, 1, 2

states of the

\mathrm{Sr}(5^{3}P_{J})

multiplet have been measured in the presence of rare-gas perturbers. For Kr and Xe pressures above 100 Torr, the rates are dominated by a component which is quadratic in pressure. We believe this very unusual behavior is brought about by the simultaneous interaction of a Sr atom with two perturbers and not by excimer formation.