Radiation from Caesium and other metals bombarded by slow electrons

The absolute intensity and intensity wave-length distribution of the radiation from Cs, Cr, Ni, Mo., and W is measured and found to be similar for all five metals. Control measurements are also made allowing the effect of surface contamination to be estimated. It is found that tiie radiation from contaminated surfaces is usually much more intense than from clean metals. It is pointed out that the similarity between the radiation from caesium and other metals makes it probable that the radiation is analogous to the continuous X rays and is not due to the excitation of electron levels characteristic of the metal.