Xenon spin polarization parameter

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. 

Figure 5.21 Spin-polarization parameters a, A, and tj as functions of the photon wavelength in the continuous range for photoelectrons leaving the xenon ion in the 5p5 2P1/2 and 2P3/2 states, respectively. The J value of the final state is indicated on the curves the vertical dashed line shows the J = 1/2 ionization threshold. Experimental data full circles [HSS86], Theoretical data full curves, relativistic random-phase calculation [HJC81] dashed curves non-relativistic random-phase calculation [Che79], From [HSS86] note /[HSS86] = 0.5 rj.

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