Polarization of theLα1X Rays of Mercury

The polarization of the $L{\alpha }_1$ characteristic x rays of mercury has been measured with respect to the emission plane. A mercury-vapor-target x-ray tube was used with a jet density such that most electrons encountered only a single exciting collision. A quartz crystal ($23\overline{5}4$) plane which diffracted the $L{\alpha }_1$ line (1. 241 20 ${\mathrm{\AA }}^{*}$) at an angle $2\theta ={104}^{\circ }$ was used as the analyzer. The observed polarization was (- 14±4)%.