Parametrization for spin observation

1 Parametrization for spin observation In analogy with the parametrization of the angle-dependent partial cross section for photoionization discussed in connection with equ. (1.50), the parametrization for the additional observation of the electron spin has to be worked out. It depends on 

With these introductory definitions, the general parametrization can be represented as [HJC81]  

The spin-dependent terms of the photoionization process are those associated with the spin-dependent Stokes parameters of the detector. There it can be seen that 

From the formulas listed, the components Px., Pr and Pz. of the photoelectron s spin-polarization vector P defined in the /, z detector frame can be calculated (for the definition of P see Fig. 1.5 and equ. (9.15)). If tr stands for transverse, long for longitudinal, and if the subscripts and 1 indicate the component within or perpendicular to the scattering plane, respectively, one gets1  

From these relations it can be seen that only circularly polarized light (nonvanishing S3) allows the determination of all spin-polarization parameters, , rj, C linearly polarized (St = 1) or unpolarized light (Sj = S3 = 0) yields only tj. Therefore, a complete experiment for 5p3/2 photoionization in xenon, where a, / , t], are needed, relies on the availability of circularly polarized synchrotron radiation. 

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