1. Pohl E 1914 Über relativbewegung von kathode und Antikathode Germany Patent DRP 376 359

2. Antikathode, there is probably at the Antikathode a greater acceleration along the line of propagation of the kathode rays than in a direction at right angles, conse-quently in a beam of X-rays proceeding in a direction perpendicular to that of the kathode stream it might …