The Heating of Anodes in X-Ray Tubes

Abstract

IN reply to Mr. Walter Chamberlain's inquiry (p, 198), it must be borne in mind that spark length is not per se a criterion of the energy delivered to a vacuum tube. The length of spark is more or less proportionate to the maximum E.M.F. of the discharge, while the energy of a discharge depends upon the nature of the curves of both E.M.F. and current, and may bear but a small relation to the maximum E.M.F. Large coils which have secondary wire of considerable section and comparatively large electrostatic capacity, give a much greater electric quantity and, consequently, much more energy for each discharge, even when worked so as to give only short of arks, than do smaller coils the secondary wire of which is of smaller section and capacity.