Title: On the accuracy of a one-dimensional approach to the solution of kinetic equations with velocity-dependent collision frequencies

The solution of many problems in light-induced gas kinetics can be simplified significantly using quantum kinetic equations in the context of the so-called one-dimensional approximation, in which the initial equations are averaged over transverse (relative to the direction of radiation) velocities. The errors introduced in such an approach are usually assumed to be small; however, this has been confirmed quantitatively only on the basis of the simplest (two- and three-level) particle models. We analyze the accuracy of the one-dimensional approximation for multilevel particles quantitatively for the light-induced drift (LID) effect in cesium atoms in the atmosphere of inert buffer gases. It is shown that in the case of the so-called “normal” LID, one-dimensional kinetic equations can always be used instead of three-dimensional equations without a risk of losing some important fine details in the dependence of the drift velocity on the radiation frequency. In the case of anomalous LID, the error of the one-dimensional approximation is also insignificant, but it can be disregarded only in the case of light buffer particles. For comparable masses of resonant and buffer particles, the one-dimensional approximation may give a noticeable error in determination of drift velocity amplitudes; however, the positions of drift velocity zerosmore » and extrema depending on radiation-frequency detuning can be described successfully. Results show that the error introduced by using the one-dimensional approximation for multilevel particles turns out to be more significant than for the simplest particle models.« less

Russian Academy of Science, Institute of Automation and Electrometry, Siberian Branch (Russian Federation)

Publication Date:

OSTI Identifier:

22309106

Resource Type:

Journal Article

Resource Relation:

Journal Name: Journal of Experimental and Theoretical Physics; Journal Volume: 119; Journal Issue: 5; Other Information: Copyright (c) 2014 Pleiades Publishing, Inc.; Country of input: International Atomic Energy Agency (IAEA)

Country of Publication:

United States

Language:

English

Subject:

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; APPROXIMATIONS; CESIUM; KINETIC EQUATIONS; MATHEMATICAL SOLUTIONS; ONE-DIMENSIONAL CALCULATIONS; PARTICLE MODELS