Polarization of TargetKX-Rays

We point out that the $K\alpha$ satellite spectra of Al target x rays exhibit strong polarizazation in ion-atom collisions. The $K{\alpha }^{\prime } ({}_{}{}^1{}_{}{}^{}P_1^{}{}_{}{}^{}\to {}_{}{}^1{}_{}{}^{}S_0^{}{}_{}{}^{})$, $K{\alpha }_3 ({}_{}{}^3{}_{}{}^{}P_{2,1,0}^{}{}_{}{}^{}\to {}_{}{}^3{}_{}{}^{}P_{2,1,0}^{}{}_{}{}^{})$, and the $K{\alpha }_4 ({}_{}{}^1{}_{}{}^{}P_1^{}{}_{}{}^{}\to {}_{}{}^1{}_{}{}^{}D_2^{}{}_{}{}^{})$ transitions are, respectively, (+52 ± 5)%, (-9 ± 5)%, and (+9 ± 5)% linearly polarized following 1.9-MeV ${\mathrm{He}}^{+}$ bombardment and (+28 ± 5)%, (-6 ± 5)%, and (+6 ± 5)% linearly polarized following 1.9-MeV ${\mathrm{H}}^{+}$ bombardment.