Optical Orientation of Atoms and Its Applications

Theory of spin polarization phenomena in atomic and molecular photoeffects

“…Based on the general structure of the transition probability (4) and density matrix of the polarized atom (3), we obtain that where γ 1 and γ 2 are scalar dynamic parameters, while the scalar A 0 coincides with the total photoionization cross section σ of the unpolarized system. Substituting these expressions for A r (n) into (22) and taking into account the definition (10) of the tensors T r and identities (9) and (15), we obtain the following general expression for the total photoionization cross section of a polarized atomic-molecular system:…”

“…With the help of formulas (A.5) and (A.6), reducing bipolar harmonics; definition (10) of tensors T r ; and identities (9) and (15), we can obtain from (11) and (12) the following expression for the sought quantities:…”

“…Let us introduce the scalar product of two irreducible tensors, (9) and the irreducible tensors T r of the rth rank, proportional to the tensors defined by (8) [17],…”

“…In deriving (14), we also used the identity [12] (15) which expresses one of the scalar products in (11) (see (9) at r = 2) in terms of the scalar products of the vectors contained in it, and took into account the explicit expression (1) for . By comparing (14) with the standard form (7) of the angular distribution of photoelectrons, we can relate σ and β with the dynamic atomic parameters introduced,…”

“…An atom is polarized upon light absorption, col-lisions, and other processes disturbing the equilibrium population of its magnetic sublevels. A special method of polarization of atoms, namely, optical pumping, has been developed (see reviews [9,10]). The state of an axisymmetrically polarized system is specified by 2 j independent quantities ( j is the quantum number of the total angular momentum), for which so-called state multipoles can be taken [11].…”