On the angular dependence of L X-ray intensity ratios for Au following photoionization

The typical L X-ray spectra for Au induced by 15.9 keV photons have been measured at emission angles ranging from 110° to 150° at intervals of 10°. The intensities of L_α, L_β1, L_β2 and L_γ1 X-rays are obtained and the angular dependence of L X-ray intensity ratios is determined experimentally. It is found that the L_β1, L_β2 and L_γ1 X-rays present isotropic emission, while the measured L_α X-rays show anisotropic distribution spatially. The unexpected isotropic emission of L_β2 X-rays is explained with Coster-Kronig vacancy transfer process. Moreover, the anisotropy parameter for L_α X-ray emission is deduced. - Highlights: • Lα X-rays are found to have an anisotropic emission in the measurement. • The alignment of L₃-subshell is disturbed by vacancy transfer process. • Different alignment behaviors in previous work have been clarified.