Experimental investigation of the origin of the TiKα″satellites

Abstract

The Ti $K{\ensuremath{\alpha}}^{\ensuremath{''}}$ satellite is investigated using a Johann-type spectrometer on the BL15XU undulator beam line of SPring-8 at excitation energies between 4996 and $7000\phantom{\rule{0.3em}{0ex}}\text{eV}$. The intensity of the $K{\ensuremath{\alpha}}^{\ensuremath{''}}$ satellite relative to that of $K{\ensuremath{\alpha}}_{1,2}$ exhibits an abrupt jump from $0%$ to $\ensuremath{\sim}1%$ in a range of $10\phantom{\rule{0.3em}{0ex}}\text{eV}$ around an excitation energy of $5010\phantom{\rule{0.3em}{0ex}}\text{eV}$. The energy range to reach saturation is $\ensuremath{\sim}500\phantom{\rule{0.3em}{0ex}}\text{eV}$. The creation of spectator holes is implicated to be due to shake-up processes, inducing the emergence of the $K{\ensuremath{\alpha}}^{\ensuremath{''}}$ satellite. The onset energy for the appearance of the satellite is $5011.0\phantom{\rule{0.3em}{0ex}}\text{eV}\ifmmode\pm\else\textpm\fi{}0\text{.8}\phantom{\rule{0.3em}{0ex}}\text{eV}$, corresponding to the $[1s3p]$ double-ionization threshold energy by a $Z+1$ approximation. The experimental results obtained in this work confirm that the $K{\ensuremath{\alpha}}^{\ensuremath{''}}$ satellite originates from a $3p$ spectator hole, as predicted theoretically by Scott [Phys. Rev. A 34, 4438 (1986)].