The N Series in X-Ray Spectra

V. Dolejsek. On the N-Series in X-Ray Spectra.
Nature. 109, p. 582 (1922).

With the aid of a powerful spectrograph for X-rays, constructed by M. Siegbahn1, the author succeeded in observing a group of lines even softer than those which belong to the \(M\) series. The author measured several such lines in the spectra of uranium and thorium. Their wavelengths lie, for uranium, between \(8.6\) and \(12.0\) Å; for thorium—between \(9.4\) and \(13.5\) Å. Apparently, these lines should be assigned to the \(N\)-series of uranium and thorium.

On the basis of the theoretical work of Coster and others, it is possible to estimate the wavelengths in the \(N\) series. In doing so, for uranium and thorium one obtains values approximately coinciding with the author’s indicated measurement results. But for bismuth and the following elements the wavelengths of all the lines prove to be greater than \(13\) Å, so that, in the present state of X-ray spectroscopy, measuring the wavelengths of these lines appears exceedingly difficult.—The author is continuing research in this direction2.

E. Shpolsky.

1. See, for example, M. Siegbahn. Jahrb. d. Rad. und El., 1921. ↩

2. At present the detailed results of this investigation have already been published. They will be reported in the next issue. —Ed. ↩