A new K-Series x-ray line due to Fermi-Sommerfeld electrons

Duane(1) has recently reported the observation of a new K-series line or band situated between the familiar gamma line and the critical limit of the K-series (position of the K absorption discontinuity.) This band is of great interest because in all probability it can be ascribed to transitions to the K level of electrons which in their initial state are dissociated from particular atoms and from a group resembling that predicted by Sommerfeld based on the Fermi statistics.