The Simplest Ubitron in Crossed Fields

We present the simplest type of an M-type ubitron in the form of a magnetically insulated coaxial diode with a cathode consisting of N individual longitudinal strips (explosive electron emitters) periodically arranged on an imaginary cylindrical surface mounted coaxially within a pipe. In spite of the simple design the operation of this device is not easily predicted, although we can definitely state that in the ubitron, as in the RPM, azimuthal recurrence provides inner feedback that leads to an absolute instability in the electron sheath-electromagnetic field interacting system; in other words, the ubitron can operate as an oscillator. The suggested oscillator can be interesting owing to its simple design and simple control of characteristics of radiation (with single frequency radiation as well as multi-mode one) by variation of the value and direction of the guide magnetic field