A New Rectifier

The authors describe a new type of cold electrode power rectifier tube utilizing gaseous conduction, and based on the following principles: No considerable gaseous conduction occurs between coaxial cylindrical electrodes separated by less than the mean free path of the electrons. An axial magnetic field (perpendicular to the electric force) will cause the electrons to pursue a longer path, and thus permit considerable conduction provided the magnetic field intensity exceeds a critical value. The critical value of the magnetic field required for producing conduction is greater for conduction from the inner to the outer electrode than in the reverse direction (that is, there are two critical values). By choosing a magnetic field intensity intermediate between the two critical values, unilateral conductivity results. Tubes constructed on this basis are described, and their performance given. The approximate mathematical theory of their action is derived.