The calculated asymmetry parameters β<sub>2</sub> and β<sub>4</sub> for second-step photoelectrons in selected transitions of sequential 2PDI S Mondal M Yao Y Mizoguchi S Yase K Nagaya A Yamada H Fukuzawa K Motomura R Ma A Rouzée 10.6084/m9.figshare.1012444.v1 https://iop.figshare.com/articles/figure/_The_calculated_asymmetry_parameters_sub_2_sub_and_sub_4_sub_for_second_step_photoelectrons_in_selec/1012444 <p><strong>Figure 2.</strong> The calculated asymmetry parameters β<sub>2</sub> and β<sub>4</sub> for second-step photoelectrons in selected transitions of sequential 2PDI. Solid (black) lines: <sup>2</sup>P<sub>3/2</sub> → <sup>3</sup>P<sub>2</sub>; long-dashed (red) lines <sup>2</sup>P<sub>3/2</sub> → <sup>3</sup>P<sub>0</sub>; short-dashed (blue) line: <sup>2</sup>P<sub>3/2</sub> → <sup>3</sup>P<sub>1</sub>; dot-dashed (green) line: <sup>2</sup>P<sub>1/2</sub> → <sup>3</sup>P<sub>2</sub>; double-dot-dashed line (magenta): <sup>2</sup>P<sub>1/2</sub> → <sup>3</sup>P<sub>0</sub>; dotted line (violet): <sup>2</sup>P<sub>1/2</sub> → <sup>3</sup>P<sub>1</sub>. The β<sub>4</sub> parameter is shown for two transitions only: <sup>2</sup>P<sub>3/2</sub> → <sup>3</sup>P<sub>2</sub>, solid (black) line and <sup>2</sup>P<sub>3/2</sub> → <sup>3</sup>P<sub>0</sub>, long-dashed (red) line. For other transitions, β<sub>4</sub> = 0 (see the text).</p> <p><strong>Abstract</strong></p> <p>Xenon atoms are double-ionized by sequential two-photon absorption by ultrashort extreme ultraviolet free-electron laser pulses with a photon energy of 23.0 and 24.3 eV, produced by the SPring-8 Compact SASE Source test accelerator. The angular distributions of photoelectrons generated by two-photon double ionization are obtained using velocity map imaging. The results are reproduced reasonably well by the present theoretical calculations within the multi-configurational Dirac–Fock approach.</p> 2013-08-13 00:00:00 velocity map imaging Photon energy sase sequential 2 PDI transition Abstract Xenon atoms Atomic Physics Molecular Physics