Alignment of the (3d104s5s)3S1

Abstract

We measure the integrated Stokes parameters of light from Zn (4s4p)4^{3}P_{0,1}-(4s5s)5^{3}S_{1} transitions excited by a transversely polarized electron impact at energies between 7.0 and 8.5 eV. Our results for the electron-polarization-normalized linear polarization Stokes parameter P_{2}, between incident electron energies 7.0 and 7.4 eV, are consistent with zero, as required by basic angular-momentum coupling considerations and by recent theoretical calculations. They are in qualitative disagreement with previous experimental results for the P_{2} parameter.

Effect of cascade transitions on the polarization of light emitted after electron-impact excitation of Zn by spin-polarized electrons

“…Our results are in excellent agreement with the general theoretical predictions made by Bartschat and Blum [6] many decades ago. Consequently, they also agree well with the P 2 /P e data of Clayburn and Gay [1] below the cascade threshold. However, our calculations raise new questions regarding, in particular, the relatively large magnitude of P 2 /P e reported in both experiments above the cascade threshold, where the agreement between the…”

“…For P 2 /P e , we continue to predict essentially zero values. Our results agree with the measurements of Clayburn and Gay [1] below the cascade threshold, while their data above that threshold agree, within the error bars, with those of Pravica et al [3]. Hence, both experimental datasets above the cascade threshold contradict general theory [6] as well as the present numerical calculations.…”

“…The dashed lines (almost indistinguishable from P1 = P2/Pe = 0 and P3/Pe = −1) are the results without cascades, while the solid lines and small circles represent the BP-BSR-43 and RCCC-94, respectively, with the cascades included. The experimental data are: triangle-up: Clayburn and Gay [1]; triangle-down: Pravica et al [3]. The published error bars on the latter are generally smaller than the symbol size.…”

“…In a recent paper, Clayburn and Gay [1] reported their measurements of the angle-integrated relative Stokes parameters (P 1 , P 2 , P 3 ) in the (4s5s) 3 S 1 → (4s4p) 3 P 0 transition in Zn. These light polarizations completely characterize the polarization state of the emitted radiation.…”

Electron-impact coherence parameters for 41P1excitation of zinc

“…This fact was discussed theoretically [4][5][6]. The experimental work by Clayburn and Gay [7] yielded the Stokes parameters P 1 and P 3 that agreed with Pravicaʼs results [3]. However, obtained P 2 values below the cascade threshold showed zero, which was in contradiction to previous measurements [3], but agreed with theoretical predictions.…”