Radiations from RaD and RaE

The electron and gamma-spectra from RaD and RaE have been thoroughly investigated. The gamma-radiation from RaD was studied with both krypton and argon proportional counters with brass and aluminum cathodes. The $L_{\alpha }$, $L_{\beta }$, and $L_{\gamma }$ radiations of Bi were observed and identified with a critical absorber. The intensity ratios of $L_{\alpha }:L_{\beta }:L_{\gamma }$ are 1:1:0.2. The previously reported 7.8-kev (10 percent) line was not found but could be strongly excited by copper backing. The weak 23-kev line (${10}^{-3\mathrm{}}$ per disintegration in our measurements) could be contributed from the piling effect of the detecting system.